SHOP MANUAL ALLIS-CHALMERS MODELS D-21, D-21 SERIES II, TWO-TEN AND TWO-TWENTY Tractor serial number is located on the front flange of the torque (clutch) housing at left hand side of tractor. Engine serial number is located on nameplate which is attached to the upper rear corner of cylinder block on the left hand side of tractor. Model D-21 tractors were available with a naturally aspirated diesel en- gine. D-21 Series II, Two-Ten and Two-Twenty tractors are equipped with a turbo-charged diesel engine. All models are available with an adjustable, wide front axle. Two-Twenty models are also available with a driving front axle (Front Wheel Assist). INDEX (By Starting ParagrapK) BRAKES Adjustment (D-21 & D-21 Series ID 105 Two-Twenty 106 R&R and Overhaul (D-21 & D-21 Series 11) 105A Two-Twenty 106A CLUTCH Engine Clutch 72 Engine Clutch Shait 76 COOLING SYSTEM Radiator 67 Water Pump 68 DIESEL FUEL SYSTEM Filters and Bleeding 51 Injection Pump 56 Injection Pump Gears 34 Nozzles 53 DIFFERENTIAL Adjustment 95 R&R and Overhaul 96 F.W.A 172 ELECTRICAL 70 ENGINE Assembly—R&R 20 Cam Followers 26 Camshaft 36 Connecting Rods & Bearings 41 Crankshaft & Bearings 42 Cylinder Head 21 Cylinder Sleeves 39 ENGINE (Cont) Flywheel 45 Front Oil Seal 43 Injection Timing 56 Main Bearings 42 o n Cooler 49 Oil Pan 46 Oil Pump 47 Piston Pins 40 Piston & Rod Removal 38 Pistons & Rings 39 Rear Oil Seal 44 Rocker Arms 27 Speed Adjustments 58 Timing Gear Cover 30 Timing Gears 31 Turbochargar 60 Valve Guides 24 Valves & Valves Seats 22 Valve Springs 25 FINAL DRIVE & DIFFERENTIAL Bevel Gears, Adjust 97 Bull Gears, Renew 100 Bull Pinion Bearings, Adjust 99 Bull Pinion, Renew 99 Differential Overhaul 96 Wheel Axle Shafts 103 FRONT SYSTEM (Without Front Wheel Assist) Adjustable Front Axle 1 Power Steering 8 FRONT WHEEL ASSIST Drive Adapter 165 Front Axle Assembly 168 Idler Gear, Shaft and Bearings 167 Lubrication 164 Power Steering 8 POWER LIFT SYSTEM Checks and Adjustments 12L 123 Filters .155 Pump 137 Valves 150,154 Work Cylinders 129 POWER STEERING 8 POWER TAKE-OFF Clutch and Brake 114.115 Controls 110,112 Output Shaft and Bearings 116,117 Reduction Gears and Shafts 113 Test and Adjust 107,109 TRANSMISSION (FRONT) Assembly, R&R 80A Countershaft 87 Mainshaft 86 Reverse Idler 85 Shifter Assembly 80 TRANSMISSION (DUAL RANGE) Bevel Pinion Shaft 92 Countershaft 94 Shifter Assembly 90 CONDENSED SERVICE DATA GENERAL Liquid Capacities D-21 Series II Cooling System 21 Qts. 31 Qts. Crmkcase (with filter) .... 12 Qts. 12 Qts. Fuei Tank 52 Gals. 52 Gals, Transmission (approx.) 21 Gals. 21 Gals. tCapacity is 15 qts. for 220 model. Front Wheels Toe-In iV-% Inch- Speeds Number Forward 8 Number Reverse 2 Electrical System Voltage ' 12 Ground Polarity Negative — No. of Batteries 2or4—— Battery Yoltage, each 12 210 21 Qts. t21 Qts. 51 Gals. 27 Gals. Printed in U.S.A. Copyright 1971 by Intertec Publishing Corp.,

D-21, D'21 Series II. 210, 220 Paragraphs 1-5 CONDENSED SERVICE DATA (Cont.) DIESEL ENGINE D-21 210 General D-21 SeHes II 220 Make Own Model 3400 3500 3500 No. of Cylinder 6 6 6 Bore—Inches 4 1/4 4 ^4 41/4 Stroke—Inches 5 5 5 Displacement-Cubiclnches 426 426 426 Compression Ratio 16:1 16:1 16:1 Firing Order 1-5-3-6-2-4 Compression Pressure @ 150 RPM* 400 psi 400 psi 400 psi 600 RPM* 500 psi 500 psi 500 psi ^Compression pressures given are approximate and at sea level. Tappets & Valves Tappet Gap, Hot 0.015 0.015 0.015 Cold 0.018 0.018 0.018 D-21 210 Valve Face & Seat Angle<- D-21 Series II 220 Intake 30'' 30* 30" Exhaust 45" 45* 45" Diesel System Pump Make Roosa-Master Injection Timing. Static . . . 34"BTDC 34"BTDC 34"BTDC Timing Mark on Crankshaft Pulley Nozzles Make Own Opening Pressure 2750 psi 2900 psi 3125 psi Governed Speed Low Idle RPM 675 675 675 High Idle RPM 2400 2400 2400 Rate Load RPM 2200 2200 2200 Tightening Ibrques (Ft.-Lbs.) General Recommendations See End of Shop Manual Cylinder Head See Paragraph 21 Crankshaft Pulley 200-220 200-220 200-220 Flywheel 95-105 95-105 95-105 Main Bearing Cap Screws. 170-190 170-190 170-190 Rod Cap Screws See Paragraph 38 FRONT AXLE SYSTEM (Models without Front Wheel Assist) SPINDLES 1. K&R SPINDLES. To remove front spindle (10—Fig. ACl), support front of tractor, remove front wheel and proceed as follows: Remove snap ring (6) and pull steering arm (8) from spindle. Remove key (K) from spindle and withdraw spindle from bottom of axle extension (5). Remove thrust washers from spindle. 2. SPINDLE BUSHINGS. Spindle bushings can be renewed after remov- ing spindle as outlined in paragraph 1. Remove bushings (7) using suitable drift punch. New bushings are pre- sized and should not require ream- ing if carefully installed. Renew thrust washers if necessary before reinstall- ing spindle. TIE-RODS AND TOE-IN 3. Refer to Figs. ACl and AC2. Toe- in of front wheels should be 1/16 to Vs-inch, and can be adjusted by lengthening or shortening tie-rods (12) equally as follows: Remove bolt (B) from outer ends of tie-rods and loosen clamp bolts (C) at inner ends. Turn the tie-rod tubes (12) in or out on inner tie-rod ends (13) to obtain correct adjustment. Reinstall and tighten bolt (B), then tighten clamp bolt (C) and recheck toe-in. Readjust if necessary. Tie-rod end sockets are non-adjust- able automotive type and except for dust cover, must be renewed as a complete unit. AXLE EXTENSIONS 4, To renew either axle extension (5—Fig, ACl or Fig. AC2), remove spindle as outlined in paragraph 1; then, remove tread width adjusting bolts and withdraw axle extension from main member. STEERING ARM 5. To renew the steering arm (15— Fig. ACl) or steering arm bushings (16), proceed as follows: Disconnect steering cylinder piston rod and tie- rods from the steering arm, then re- move steering arm from pivot pin (P) on the crossbar in front axle main member. 17 Fig. ACl — Exploded view of Model D-21 front axle ossembly. Bolt (R) retains front pivot pin (3). To ad|ust front wheel toe-in, remove boit (B), loosen clamp (C) and turn tie rod tube (12) In or out as required. B. Bolt C. Clamp K. Key P. Pivot for (15) R. Retainer bolt 1. Rear pivot bolt 2. Axle main member 3. Front pivot pin 4. Flat washer 5. Axle extension 6. Snap ring 7. Spindle bushings 8. Spindle arm 10. Spindle 11. Outer tie rod end 12. Tie rod tube 13. Inner tie rod end 15. Steering arm 16. Bushings 17. Retainer washer 3

Paragraphs 6-7 Drive the bushings (16) out of steering arm using a suitable bushing driver. New bushings are pre-sized and should not require reaming if carefully installed. The steering arm pivot pin (P) is an integral part of the axle center (main) member and radius rod assem- bly. AXLE CENTER (MAIN) MEMBER AND PIVOT PINS 6. The axle center (main) member and the radius rods are welded one- piece assembly (2—Fig. ACl or Fig. AC2). The center member pivots on a bolt (1) at rear end of assembly and a pin (3) at front end. The bolt and pin pivot in renewable bushings in the clutch (torque) housing and in the front support casting. To renew the pivot bolt or pivot pin, proceed as follows; Support trac- tor under the torque housing so that no weight is carried on the front axle. Then, remove the retaining bolt (R— Fig. ACl) and drive the front pivot pin out towards front of tractor. The plug (3—Fig. AC3) with lubricating fitting will be driven out with pin. Then, raise front of tractor until front support is clear of axle and drive bushing (2) out to rear with suitable driver. New bushing is pre-sized and should not require reaming if care- fully installed. Install pivot pin and retaining bolt, then drive the plug (3) into front support with a hollow driver so that plug is flush with cast- ing. To remove rear pivot bolt, support rear (radius rod) end of axle main member and remove cotter pin and Fig. AC2 — View show- ing front axie extension. Toe-in should be correct for each treod width po- sition when bolt (B) is iocated in proper notch (N) in tie rod. Refer to Fig. ACl for iegend. slotted nut from pivot bolt. Then, re- move pivot bolt from axle and torque housing. Drive bushing out of torque housing. New bushing is pre-sized and should not require reaming if care- fully installed. Install pivot bolt through torque housing, install slotted nut and tighten nut to a torque of 150 Ft.-Lbs. If slot in nut does not align with hole in bolt, continue to tighten nut until cotter pin can be inserted. To renew the axle center (main) member, remove both axle extensions as outlined in paragraph 4, disconnect rear end of power steering cylinder, remove steering arm from pivot pin and remove the front axle pivot pin and rear pivot bolt. i^ ALLIS-CHALMBRS FRONT SUPPORT 7. The front support (1—^Fig. AC3) is a heavy one-piece casting. The front axle pivot bushing (2) and plug (3) can be renewed as outlined in para- graph 6 without removing the front support. To remove front support for other jobs, proceed as follows: Drain the cooling system. Remove hood and air cleaner to intake manifold tube. On Two-Twenty models, disconnect hydraulic lines to the oil cooler. On all models, disconnect both radiator hoses, then unbolt hood front support panels from side rails, and remove the panels, radiator and air cleaner as a unit. Disconnect front of steering cyl- inder from steering arm (15—^Fig. ACl). Support the tractor under torque housing so there is no weight on front axle pivot pin. Attach a hoist to front support at lifting point pro- vided, remove cap screws retaining side rails to front support and remove the front support from side rails and front axle pivot pin. NOTE: If front support casting binds between the side rails, loosen the bolts retaining side rails to engine front support plate. Any front end weights attached to front support casting should be re- moved before unbolting and removing the front support. POWER STEERING SYSTEM All models are equipped with hydrostatic power steering system that has no mech- anical linkage between the steering wheel and tractor front wheels. Refer to Fig. AC4 for drawing showing the steering system. Power for steering is supplied by a gear type pump that is driven from the engine timing (camshaft) gear. On models with a hydraulic lift system, the hydraulic and power steering pumps are an integral unit. Transmission oU is utilized as fluid for the system. The control valve unit (1—Fig. AC4) con- tains a rotary metering motor, a commuta- tor feed valve sleeve and a selector valve spool. In the event of engine or hydraulic power failure, the metering motor becomes a rotary hand pump to actuate the power steering cylinder when the steering wheel is turned. A check valve within the control Fig. AC3—View of front support easting and r^ iated parts. Additional flat front weigiits can be boited onto the weight shown. 1. Front support 2. Pivot bushing 3. Plug 4. Front weight valve housing allows redrculation of fluid within the control valve and steering cylin- der during manual operation. NOTE: The maintenance of absolute cleanliness of all parts is of the utmost importance in the operation and servicing of the hydraulic power steering system. Of equal importance Fig. AC4—Drawing showing components of hydrauiic power steering system. No me- clionicoi linicage is used between the steer- ing wheei and troctor front wheeis. Note that the components are not located in po- sition in which they are installed on trac- tor. Cooier (8) is not used on D-21 modeis. 1. Control valve unit 2. Pressure tube 3. Return tube 4. "Right turn" tube 5. "Left turn" tube 8. Oil cooler 9. "T" fitting to PTO valve

Q.21. D-21 Series II. 210, 220 Poragraphs 8-lOA i8 the avoidance of nicks or hvms on any of the working parts. Do not use cloth shop towels in cleaning the system internal parts; use only lint free power shop towels. TROUBLE SHOOTING 8. Before attempting to adjust or repair the power steering system, the cause of any malfunction should be located. Refer to the following para- graphs for possible causes of power steering system malfunction: Irresrular or "Sticky" Steering. If irregular or **sticky" feeling is noted when turning the steering wheel with forward motion of tractor stopped and with engine running at rated speed, or if steering wheel continues to ro- tate after being turned and released, foreign material in the power steering fluid (transmission oil) is the prob- able cause of trouble. Clean or renew all hydraulic system filters. It may be necessary to also drain the trans- mission oil and refill with clean oil. If trouble is not corrected, the power steering valve assembly should be re- moved and serviced; refer to para- graph 12. Steering Cylinder "Hesitates". If steering cylinder appears to pause in travel when steering wheel is being turned steadily probable cause of trouble is air trapped in the power steering cylinder. Bleed the cylinder as outlined in paragraph 9. Slow Steering. Slow steering may be caused by low oil flow from pump. Check time required for full stroke travel of power steering cylinder; first with tractor weight on the front wheels, then with front end of trac- tor supported by a jack. If time be- tween the two checks varies consider- ably, overhaul the power steering pump as outlined in paragraph 139. Loss of Power. Loss of steering power may be caused by system re- lief setting being too low. Check and adjust relief valve setting as outlined in paragraph lOA or lOB. System Overheats. Overheating of system may be caused by neutral (by- pass) pressure being too high. Check neutral pressure as outlined in para- graph lOA. If neutral pressure is ex- cessive, check for obstructions in sys- tem such as kinked tube, etc. If neu- tral pressure is erratic, check for bind- ing of control valve shaft, spool and/ or sleeve. LUBRICATION AND BLEEDING 9. Transmission lubricating oil is utilized as the power steering fluid; refer to note preceding paragraph 80. The power steering system is usually self-bleeding. With engine running at high idle speed, cycle system through several full strokes of the cylinder. In some cases, it may be necessary to loosen connections at cylinder to bleed trapped air. Fig. AC4A—View of OTC hydraulic fesfer connected to D-21 fracfor for testing the power steering system. Both pressure and return tubes must be disconnected from pump and return connection must have cap CO installed. Outlet hose must return oil to sump OS shown. SYSTEM OPERATING PRESSURE AND RELIEF VALVE 10. Tests of the power steering sys- tem will disclose whether the pump, relief valve or some other unit in the system is malfunctioning. To make such a test, proceed as outlined in the appropriate following paragraph: D-21 and D-21 Series II 10A. Power steering relief pressure can be checked by connecting a high pressure (3000 psi) hydraulic gage into the pressure line between the pump and power steering control valve. Turn the steering wheel to one end of its travel and hold in that position only long enough to read the pressure gage. CAUTION. Never hold steering wheel in this position for longer than a few seconds at a time; overheating of oil and possible damage to pump will occur if wheel is held in this position for an extended period of time. System relief pressure should be 1500 PSI at 2200 engine RPM. Pres- sure relief valve is located in mani- fold of hydraulic pump and can be adjusted as outlined in paragraph 141. Check the neutral (by-pass) system pressure as follows: With pressure gage connected as outlined in preceed- ing paragraph, slowly turn steering wheel in each direction and stop wheel in position that shows lowest gage reading; this reading is the neu- tral (by-pass) pressure. Turn wheel to limit stop in either direction and hold wheel against stop for one to two seconds, then release the wheel; gage pressure should drop to nearly the same as neutral pressure reading. If gage remains considerably higher than neutral pressure reading, a bind- ing control shaft or foreign material between control valve sleeve and valve spool is indicated. A hydraulic tester (such as OTC Y81-21) can be connected as shown in Fig. AC 4A to check pump volume and relief pressure. The outlet hose should be routed to sump as shown. With engine operating at approxi- mately 1600 RPM, close the tester valve until pressure is approximately 1200 psi. When oil temperature reaches 100* F., the volume of flow should be 5.25 GPM with engine speed be- tween 1050 and 2200 RPM. With tester valve completely closed, pres- sure should be 1500 psi. Add or re- move shims under pressure relief valve plug to change pressure. The pump and/or flow control valve should be serviced if volume of flow is incorrect.

Paragraphs 10B-13 ALLIS-CHALMERS 210 and 220 Models lOB. The PTO clutch (on models so equipped) is operated by return or by-pass oil from the power steering system. PTO clutch operating pres- sure must be tested as outlined in paragraph 109 before checking power steering relief pressure. Power steering relief valve pres- sure on all models can be checked by installing a high pressure (3000 psi) hydraulic gage in port (P-Fig. AC4B) after removing the plug. Turn the steering wheel briefly to one end of its travel and observe pressure. If tractor is not equipped with PTO, power steering relief pressure should be 1690-1810 psi. If tractor is equipped with PTO, relief pressure should be 1925-2075 psi. Power steering relief pressure can be adjusted at screw (S) after removing cap nut (C). The neutral by-pass system pressure can be checked as outlined in paragraph lOA. The flow divider located in pump rear cover first supplies 4.25 GPM of Fig. AC4B—Power sfeering pressure can be checiced at port (P) on 210 and 220 tractors. Reiief vaive adiusting screw (S) and cap nut (C) are iocated on engine Me of pump. Fig. AC5 — View of steering controi vaive showing port locations. Pressure tube from pump connects to " i N " port; return tube to sump connects to "OUT" port; tube to rear end of cylinder connects to "L" (left turn) port; and tube to rod end of cyiinder con- nects to "R" (right turn) port. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. Id. 20. 21. Oil seal Mounting plate Qua4 ling eeal "0" ring Bushing **0" ring Plug Check seat Check valve Valve spring Control valve body Centering springs (6) Centering pin Sleeve Valve spool Plate Drive shaft Rotor Ring Spacer Cover (cap) vr Fig. AC6—Exploded view of steering control valve assembly which is shown assembied in Fig. AC4. Centering springs (12) are instGiied in two groups of three springs with arch in each group back-to-bacic. Some modeis are equipped with needie thrust bearing (5A & 5B) and different type locator bushing (5C). oil to the power steering system, with remainder of oil used for the power lift system. A hydraulic tester (such as OTC Y81-21) can be attached to port (P—Fig. AC4B) with outlet from tester routed to sump filler opening. With engine operating at approxi- mately 1600 RPM, first check relief pressure. Refer to preceeding para- graph for recommended settings. Open tester valve until pressure is approxi- mately 300 psi below relief pressure and observe volume of flow. Volume should be 4.25 GPM with engine speed between 1050 and 2200 RPM. The pump and/or flow divider valve should be serviced if volume of flow is incorrect. POWER STEERING PUMP 11. A gear type pump driven from the engine camshaft gear is used as the power source for the steering system. On tractors equipped with a hydraulic system, the power steering pump is an integral part of the hy- draulic system pump. For service information on the pow- er steering pump, on tractors both with and without a hydraulic system, refer to paragraph 139. CONTROL VALVE 12. REMOVE AND REINSTALL. Remove the hood and disconnect the four hoses from control valve. Unbolt and remove the control valve as- sembly from the steering shaft hous- ing. Reinstall the control valve assembly by reversing the removal procedure. Refer to Fig. AC5 for proper hose locations. Install new "O" ring seals on the hose fittings before connecting hoses to control valve and tighten fittings securely. Bleed trapped air from the power steering cylinder as outlined in paragraph 9 after assembly is completed. 13. OVERHAUL CONTROL VALVE. After removing the control valve as- sembly as outlined in paragraph 12, proceed as follows: Clean the valve thoroughly and remove paint from points of separation with a wire brush. Note: A clean work bench is neces- sary. Also, use only lint free paper shop towels for cleaning valve parts. If oil leakage past seal (1—Fig. AC6) is the only difficulty, a new seal can be installed after removing the mounting plate (2) only. Remove plug (7) from valve body with a bent wire, install new "O" ring on plug, lubricate plug and *'O" ring with mo- tor oil and reinstall in valve body. In- stall new quad seal (3) and "O" ring (4) in mounting plate, reinstall mounting plate and tighten retaining cap screws equally to a torque of 250 inch-pounds. To completely disassemble and over- haul the power steering control valve, refer to exploded view in Fig. AC6 and proceed as follows: Clamp valve mounting plate in vise with cap end of valve up. Remove end cap retain- ing cap screws. Remove end cap (21), gerotor set (18 & 19), plate (16) and drive shaft (17) from valve body as a unit. Remove valve from vise, place a clean wood block in vise throat and set valve assembly on block with mounting plate (2) end up. Lightly clamp vise against port face of valve

D-21. D-21 Series II, 210. 220 Paragrapks 14-15 1 17 2 3 4 6 16 11 13 12 13 16 15 15 16 8 9 5 Fig. AC7—View of eorly power steering cylinder. Refer to Fig. AC8 for later type. 1. Cylinder rod 2. Snap ring 3. Spacer 4. Snap ring 5. Support G. *'O" ring 8. Back-up ring 9. "O** ring body and remove mounting plate re- taining screws. Hold spool assembly down against wood block while re- moving mounting plate. Remove valve body from vise and place on work bench with port face down. Carefully remove spool and sleeve assembly from 14-hole end of valve body. Use bent wire to remove check valve plug (7) and use ^^-inch Allen wrench to remove check valve seat (8). Then remove check valve (V4-inch steel ball) (9) and spring (10) from valve body. Remove centering pin (13) from spool and sleeve assembly, hold sleeve and push spools (splined end first) out of sleeve. Remove the six center- ing springs (12) from slot in spool. Separate the end cap and plate from the gerotor set and remove the drive shaft, rotor and spacer. Inspect all moving parts for scor- ing. Slightly scored parts can be cleaned by hand rubbing with 4D0 grit abrasive paper. To recondition gerotor section surfaces place a sheet of 600 grit paper on plate glass, lap- ping plate or other absolutely flat surface and remove sharp particles from paper with a flat piece of scrap steel. Stroke each surface of the gerotor section over the abrasive paper; any small bright areas indicate burrs that must be removed, Polish each part, rinse in clean solvent and air dry; keep these parts absolutely clean for reassembly. Renew all parts that are excessively worn, scored or otherwise damaged. Install new seal kit when reassem- bling. To reassemble valve, proceed as fol- lows: Install check valve spring with small end out. Drop check valve ball on spring and install valve seat with counterbored side towards valve ball. Tighten seat to a torque of 150 inch- pounds. 10. "O" ring 11. Piston 12. "O" ring 13. BacU-up rings 14. Lock nut 15. Swivei 16. Tube seats 17. Snap ring 18. Scraper Lubricate the valve spool and care- fully insert spool in valve sleeve using a twisting motion; be sure that spring slots in spool and sleeve are at same end of assembly. Stand the assembly on end with spring slots up and aligned. Assemble the springs in two groups with extended edges of springs down. Place the two groups of springs back-to-back (arched sec- tions together) and install the springs into the spring slot in sleeve and spool in this position. Use a small screwdriver to guide the springs through slots in opposite side of as- sembly. Center the springs in the sleeve with edges of springs flush with upper surface of sleeve. Insert centering pin (13) through the spool and sleeve assembly so that both ends of pin are below flush with outside of sleeve (14). On some models, nylon plugs are located at ends of centering pin to prevent pin from contacting inside diameter of valve body. Care- fully insert spool and sleeve assem- bly, splined end first, in 14-hole end of valve body (11). Set valve body on clean surface with 14-hole end down. Install new "O" ring (6) on check valve plug (7), lubricate plug and insert in check valve bore. Install locator bushing (5 or 5C) in valve bore with chamfered side up. On models so equipped, in- stall thrust bearing assembly (5A and 5B) over valve spool (15). Install new quad seal (3) and *'O" ring (4) in mounting plate, lubricate seal and in- stall mounting plate over valve spool and locator bushing. Tighten the mounting plate retaining screws evenly to a torque of 250 inch-pounds. Clamp the mounting plate in a vise with 14-hole end of valve body up. Place plate (16) and gerotor outer ring (19) on valve body so that bolt holes align. Insert drive shaft (17) in gerotor inner rotor so that slot in shaft is aligned with valleys in rotor and push shaft through rotor so that about Vi of length of the splines pro- trude. Holding the shaft and rotor in this position, insert them in valve housing so that notch in shaft engages centering pin in valve sleeve and spool. Install spacer (20) at end of drive shaft; if spacer does not drop down flush with rotor, shaft is not properly engaged with centering pin. Install end cap and tighten the retain- ing screws equally to a torque of 150 inch-pounds. POWER STEERING CLYINDER 14. REMOVE AND REINSTALL. Thoroughly clean cylinder and hose fittings to avoid entry of dirt when lines are disconnected. Turn front wheels to right as far as possible. Re- move the bolt at each end of cylinder. Disconnect hose fittings at cylinder and remove cylinder from tractor. Work the cylinder piston each way to end of stroke to expel all excess oil. Note: Only about 1 pint of oil will drain from hose when cylinder is disconnected. When reinstalling cylinder, first at- tach hose fittings leaving the flare nuts loose. Install the two bolts retain- ing cylinder to crossbar and piston rod to steering arm with bolt heads up, then tighten the nuts and secure with cotter pins. Check to see that hoses are properly located, then tight- en the flare nuts. Bleed the power steering system as outlined in paragraph 9, check trans- mission oil level and add oil as neces- sary to bring oil level to full mark on dipstick, 15. OVERHAUL STEERING CYL- INDER. After removing power steer- ing cylinder as outlined in paragraph 14, refer to Fig. AC7 or AC8. The earlier type is shown in Fig, AC7. On early models (Fig. AC7), re- move snap ring (2) and withdraw spacer (3) from cylinder tube. Push support (5) into tube far enough to remove snap ring (4), Remove snap ring, then use piston rod to bump the support out of the cylinder tube. Re- move nut (14) from inner end of piston rod, carefully remove the burr left from staking nut to rod, then remove piston (11). Remove **O" ring (10) and slide the support (5) off rod. On later models (Fig. AC8), re- move fitting (20) push support (5) into tube far enough to remove snap ring (4). Remove snap ring, then use piston rod to bump the support out of cylinder tube.

ParograpKs 20-21 ALLIS-CHALMBRS 19 21 6 5 11 22 23 22 IB Fig. AC8—View 7. Cylinder tube 19. Scraper 20. FlttlnK 25 steering cyiinder. Refer to Fig. AC7 for iegend except tiie foiiowing. 21. Back-'ip ring 22. Split wear ring 23. Sealing ring 24. "O" ring 25. Nut The sharp edge of scrapers (18— ?ig. AC7 and 19—Fig. AC8) should 3e toward outside. Refer to Figs. AC7 k AC8 for remainder of assembly. Stake the piston retaining nut to rod ifter tightening. Support (5) must be )ushed into cylinder enough to in- tall snap ring (4), then bump the upport back out against snap ring )y pulling on rod. On later models, nake certain that hole in support is aligned with hole in cylinder, so that fitting (20—Fig. AC8) can be in- stalled. On all models be sure that all parts are lubricated when assem- bling and carefully work seals onto rod and into cylinder. ENGINE AND COMPONENTS R&R ENGINE WITH CLUTCH ASSEMBLY 20. To remove the engine, first re- move the cover(s) from the batteries and disconnect all battery ground straps. Note that each battery has a separate ground strap. Then, proceed as follows: Drain oil pan if engine is to be disassembled. It is not necessary to drain the transmission as front end of pump suction tube is higher than transmission oil level. Remove the front support casting as outlined in paragraph 7. Unbolt and remove both side rails from tractor. Disconnect the starter cable from starting motor and disconnect all wiring to engine elec- trical units by separating the plug-in connectors or detaching from elec- trical units. Move wires out of the way. Disconnect power steering, hy- draulic system and "Traction Booster** lines from pump, remove clamps and reposition lines away from^ engine. NOTE: Cap all openings as lines are disconnected. Shut off fuel supply and disconnect fuel lines. Disconnect speed control rod, fuel shut-off cable (or wires) and engine hour-meter cable. NOTE: Depending on reason for en- gine removal, it may be easier to re- move other components from engine at this time. Attach hoist to lift hooks provided at front and rear end of cylinder head, then unbolt and remove the en- gine from torque housing. Refer to Fig. ACIO. Reinstall engine and clutch assem- bly by reversing removal procedures. Bleed the fuel system as outlined in paragraph 51 and, if necessary, bleed the power steering system as outlined in paragraph 9. CYLINDER HEAD 21. REMOVE AND REINSTALL. Drain cooling system and remove air cleaner inlet cap and pipe, hood top and side panels. Disconnect upper ra- diator hose from thermostat housing and remove tube from air cleaner to intake manifold or turbocharger. Dis- connect water by-pass tube from wa- ter pump and thermostat housing, dis- connect temperature gage sender switch wire and remove thermostat housing from cylinder head. On turbo- charged models, remove the turbo- charger. On all models, remove ex- haust manifold. Remove the intake manifold if so desired. Disconnect breather tube from rocker arm cover, remove rocker arm Fig. ACIO—View of engine removed from D-21 tractor. Two-Ten, Two-Twenty and D-21 Series II engines are simiiar. 1. Lift hook 2. Lift hook 3. Oii filters 4. TDO timing pin 5. Fuel primer pump 6. Fuel filter 7. Timing window 8

D-21, D.21 Series II, 210, 220 Paragrophs 22-23 cover, remove oil supply line to rock- er arm assembly and equally loosen and remove the rocker arm assembly retaining cap screws. Lift off rocker arm assembly and remove the push rods. Disconnect fuel return line at front injector and cap all openings as each line is disconnected. NOTE: Although not required for removal of the cylinder head, it is recommended that the fuel injector assemblies be removed from cylinder head at this time. The in- jector nozzle tips protrude through the flat bottom surface of the cylinder head and, if injectors are not removed, extreme care must be taken when removing and handling the removed cylinder head. Remove the cylinder head retain- ing cap screws and carefully pry cyl- inder head up off of the dowel pins (DP—Fig. ACll) located at front and rear of cylinder block. Lift cylinder head from tractor. When reinstalling cylinder head, be sure that gasket surfaces of cylinder head and block are clean and free of burrs. Check cylinder liner standout as outlined in paragraph 39, Place new gasket with side marked "THIS SIDE DOWN" against cylinder block and be sure gasket is properly lo- cated on the two dowel pins. Note: Do not apply grease or gasket sealer to gasket surfaces, block or cylinder head; new gasket is treated with phe- nolic sealer. Locate fire rings around cylinder sleeves then position cylin- der head on the dowel pins. Lubricate the cylinder head retaining cap screws with motor oil and install the 20 short cap screws as indicated in View "A", Fig, AC12; tighten the short cap screws to a torque of 90-100 Ft.-Lbs. in sequence shown. Install the push rods and rocker arm assembly. Start- ing in the center and working toward each end, tighten the six long cylinder head retaining cap screws to a torque of 90-100 Ft.-Lbs. Retighten all 26 cylinder head retaining cap screws to a torque of 130-140 Ft,-Lbs, in se- 17 16 8 ? 14 15 20 Fig. ACl 2 — Drawing showing proper sequence for tightening cylinder head retaining capscrews. Refer to paragraph 21 for procedure and torque values. VIEW " ^ f oQo I oQoToQo T oOo foOo | , 18 14 10 6 1 15 19 23 quence shown in View "B'*, Fig. AC 12, and tighten the six %-in rocker arm bracket cap screws to a torque of 28- 33 Ft.-Lbs. NOTE: Adt.pter must be used to correctly tighten the screws located under rocker arm shaft. Ad- just valve tappet gap cold as outlined in paragraph 28, start engine and bring to normal operating tempera- ture. After engine has operated for one hour (preferably under load), re- torque the cylinder head screws and readjust valve gap hot. After ten hours of normal tractor operation, retighten the cylinder head cap screws to a torque of 130-140 Ft.-Lbs, and re- adjust valve tappet gap to 0.015 hot, NOTE: All torque values are given ior clean threads lubricated with motor oil. Allis-Chalmers recommends that no other type of thread lubricant be used, VALVES AND VALVE SEATS Intake Valves 22. Intake valves have a face and seat angle of 30 degrees, A one degree interference angle may be used by machining the seat to 31 degrees. The seat width can be narrowed by using 15 and 60 degree stones to obtain the Fig. ACn — View of engine showing cyiinder head removed. Note the cylinder head locating dowei pin CDP) at each end of biock. Cylinder numbers (CN) ore stamped on side of piston towards the camshaft. Disregard number stamped on opposite side of piston. desired seat width of ^-inch. Intake valve stem diameter is 0,3715-0.3720, Intake valves seat directly in the cylinder head although intake valve seats are available for service. When installing service intake valve seat in- serts, machine counter bore in cylin- der head to a diameter of 1.814-1,815 and to a depth of 0.4585-0.4605, Out- side diameter of seat insert is 1,816- 1,817 which provides a 0.001-0,003 in- terference fit. Surface of intake valve head must be recessed at least 0.054 from cylin- der head surface to provide proper clearance between valve head and the piston. Exhaust Valves 23, Exhaust valves have a face and seat angle of 45 degrees. A one degree interference angle may be used by machining seat to 46 degrees. The seat width can be narrowed by using 30 and 60 degree stones to obtain desired seat width of ^-inch. Exhaust valve stem diameter is 0,3705-0,3710. Exhaust valves seat in renewable inserts. Seat insert diameter of 1.667- 1.668 provides a 0.001-0,003 interfer- ence fit in the 1,665-1.666 diameter counterbore in cylinder head. If new exhaust valve seat insert fits too loosely, machine the counterbore di- ameter to 1,670-1,671 and install a 0,005 oversize insert. Depth of the counterbore should be 0,4735-0,4755 for both the standard size and 0.005 oversize inserts. Stake the seat insert at 3 points 120° apart after seat is in- stalled. NOTE: Do not stake the seat near the injector nozzle hole. Surface of exhaust valve head must be recessed at least 0.053 from cylin- der head surface to provide proper clearance between valve head and the piston.

Paragraphs 24-27 ALLIS-CHALMERS VALVE GUIDES 24. Renew valve guides when stem to guide clearance exceeds 0.0035 on intake valves or 0.0055 on exhaust valves. Desired stem to guide clear- ance is 0.001-0.0015 for intake valves and 0.002-0.0025 for exhaust valves. Intake and exhaust valve guides are interchangeable. When installing new guides, press new guides in from bot- tom of cylinder head. The top of in- take valve guides should be 25/32- inch from counterbore around guide and bottom of guide should be ap- proximately 1%-inches from cylinder head gasket surface. The top of ex- haust valve guides should be 1^- inches from counterbore around guide and bottom of guide should be approx- imately lH-inches from cylinder head gasket surface. Refer to Fig. AC13. After installing guides, ream inside diameter of both intake and exhaust valve guides to 0.373 to provide proper stem to guide clearance. VALVE SPRINGS 25. The interchangeable intake and exhaust valve springs should be re- newed if rusted, distorted or if they vary more than 5% from following specifications: Pounds pressure @ 2,237 inches 40-46 Pounds pressure @ 1.780 inches 105-115 Spring free length, approx 2JJ inches Spring are installed with flat steel dampener coil inside spring. Spring or dampener coil are not available sepa- rately. CAM FOLLOWERS 26. The 0.748-0.7485 diameter mush- room type cam followers (valve lift- ers) ride directly in unbushed cylin- der block bores and can be removed after removing the camshaft. Cam fol- lowers are available in standard size only and should be renewed if either end is chipped or worn or if they are loose in cylinder block bores. Desired follower to bore clearance is 0.001- 0.0025. Fig. AC13 —yr«w $how- inq method of measuring vaive guide height above eyiinder head counterbore when instaiiing new valve guides. Refer to para- graph 24. Fig. ACT4—^View of roeicer arm assembiy and related parts. Disconnect oUing tube (OT) from rear end of roeicer arm shaft before removing the assembiy. Note the position of shaft locating capscrew (LC). Oii return tube (RT) is iocated at front end of roeicer arm ROCKER ARMS 27. R&R AND OVERHAUL. Rocker arms and shaft assembly can be re- removed after removing hood top and rear side panels, disconnecting breath- er tube and removing rocker arm cover and oiling tube. Loosen and remove all retaining cap screws equally, then lift rocker arms and shaft assembly from the cylinder head. The hollow rocker arm shaft is drilled for lubrication to each rocker arm. Lubricating oil to the oiling tube is supplied through a drilled passage in cylinder head and engine block. To disassemble the rocker arms and shaft assembly, remove the hex plugs, spring washers and spacer washers from each end of shaft and remove locating cap screw and lock washer from No. 3 rocker arm support. Slide the rocker arms, supports and spacer springs from shaft. Rocker arm shaft diameter is 0.999- 1.000. Bore in rocker arm is 1.001- 1.002 providing a clearance of 0.001- 0.003 between shaft and rocker arms. If clearance is excessive, renew the shaft and/or rocker arms. All rocker arms are alike. To reassemble the rocker arms and shaft assembly, proceed as follows: Place shaft on work bench with end nearest to the detent hole (DH—^Fig. AC15) to left. Slide rocker arm sup- port with locating capscrew (LC) on shaft with flat mounting surface down and large capscrew hole towards you. Tighten the locating capscrew into the hole in shaft to 28-33 Ft.-Lbs. torque. Complete the assembly of rocker arm shaft using Figs. AC 14 and AC 15 as a guide. End plugs (12—Fig. AC15) should be torqued to 40 Ft.-Lbs. The restrictor elbow (7) with a ^-inch opening should be installed in rear plug and the inlet oil line (16) should be attached. The elbow at front is not a restricted type. Before reinstalling the rocker arm assembly, loosen each tappet adjusting screw about two turns to prevent in- terference between valve heads and pistons due to interchanged compo- nents. Tighten the %-inch support re- taining capscrews to a torque of 28- 33 Ft.-Lbs. and the A-inch (cylinder head) capscrews to a torque of 130- 140 Ft.-Lbs. Adjust valve tappet clear- ance cold as outlined in paragraph 28. Complete the reassembly of tractor, then readjust tappet clearance after engine has reached normal operating temperature. 10

D-2T. D-21 Series II, 210. 220 Paragraphs 28-30 VALVE CLEARANCE 28. Because of the limited clearance between the head of the valve and top of piston, valve clearance (Tappet Gap) should be checked and adjusted only with engine stopped. After any service to valve system, valve clear- ance should be adjusted cold before engine is started. Valve clearance should be rechecked with engine at operating temperature. Clearance Cold— Inlet & Exhaust 0.018 in. Clearance Hot— Inlet & Exhaust 0.015 in. Fig. AC15 — View of vaive octuaffnq parts. Upper drawinq shows rocker arm shaft assem- bled with locating cap- screw at inset. Restrictor elbow (7) U on inlet tube at rear. Thrust plate (3) may encircie cam- shaft on some modeis. Locating capscrew Camshaft gear Lock plate Thrust plate Camshaft Cam follower Oiling tube Elbow fitting Pushrod Rocker arm shaft Washer Wave washer End plug on return tube Rocker arm Support Cylinder head capscrew Self-lock ing screw Spacer spring Two-position adjustment of all valves is possible as shown in Figs. AC15A & AC15B. To make the adjust- ment turn the crankshaft until No. 1 cylinder is at TDC on compression stroke. Mark on crankshaft pulley (Fig. AC43) indicates TDC and if clearances are nearly correct, both front rocker arms will be loose and both rear rocker arms will be tight with No. 1 cylinder on compression stroke. Adjust the six valves indicated in Fig. AC15A to the correct clear- ances. Turn the crankshaft one com- plete revolution until TDC marks are again aligned. This will position No. 6 cylinder at TDC on compression stroke. Adjust the remaining six valves shown in Fig. AC15B. NOTE: When adjusting valve tappet clear- ance, be sure to note that the intake valve rocker arm is always to the right side of rocker arm support (as viewed trom left side ol engine) and exhaust valve rocker arm is to left side of support. There is a rocker arm support between the rocker arms for the valves of each cylinder. Refer to Fig. AC14. TIMING GEAR COVER AND CRANKSHAFT FRONT OIL SEAL 30. REMOVE AND REINSTALL. To remove the timing gear cover, first remove the front support casting as outlined in paragraph 7, then proceed as follows: Remove the fan blades, fan belts and the cap screw and washer from front end of crankshaft. Using a pull- er threaded into the tapped holes in crankshaft pulley hub as shown in Fig. AC 16, remove pulley from crank- shaft. CAUTION: Do not attempt to remove pulley by pulling on outer diameter as vibration dampener built into pulley will be damaged. It is suggested to loosen all oil pan cap screws enough to lower the front of oil pan or preferably remove oil pan. Remove the plate from cover in front of the fuel injection pump drive gear and remove the thrust plunger if so equipped. Remove screws that attach timing gear cover to front of crankcase, and carefully pry cover forward to slide seal and cover for- ward off of crankshaft. NOTE: Some of the attaching screws enter from FRONT E l E l E l E l E l E I E I E I E 1 E 1 Fig. AC15A—With No. T cylinder at TDC on com- pression stroke, a d I u s t toppet gap on valves shown. Refer to text for clearance. Fig. AC15B—With No. 6 cylinder at TDC on com- pression stroke and No. 1 cylinder at TDC of ex- haust sTroke, adiust valves shown. Refer to text for recommended clearance. E I Fig. ACT6~Do not pull crankshaft pulley by outer rim; thread iiuliers into hub of pulley as shown. Place correct size center plug over end of cranicshaft after remov- ing pulley retaining oipscrew (CS) and washer. 11