Rebuilding the New Process 435
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Ford & Chrysler 4-speed manual transmissions use aluminum identification tag secured by 2 bolts on power take-off cover. Information on tag includes part number, model, and build date. The main case of an NP435 is 10 13/16" front-to-back across the mounting surfaces; the 4WD extension is 8".
New Process 435 4-speed transmission uses top-mounted shift lever and cover. Spur cut gears are used for 1st and reverse speeds. Helical cut gears, synchronized for easier shifting are used for 2nd, 3rd and 4th speeds.
Input shaft is supported at front by tapered roller bearing. Endplay is controlled by gasket thickness between case and bearing retainer. Front of mainshaft is supported by pilot roller bearing in input shaft. Rear of mainshaft is supported by ball bearing that is pressed onto shaft and held in case by snap ring.
Countershaft and gears are integral one-piece design. Countershaft gear is supported by caged roller bearings at each end. Roller-type thrust bearing and race are provided at rear of countershaft gear, with thrust washer at front of gear.
Reverse idler gear is serviced as assembly. The 3rd-4th speed synchronizer is mounted at front of mainshaft. The 2nd speed synchronizer and 1st speed sliding gear is mounted at rear of mainshaft.
SERVICE (IN VEHICLE)
Following gearshift lever procedure applies to Ford Motor Co. vehicles only. Remove shift ball only if shift ball, boot or lever is to be replaced. If ball, boot, or lever is not being replaced, remove ball, boot and lever as an assembly.
1) Remove plastic insert from shift ball. Warm ball with heat gun to 140-180°F (60-80°C). Knock ball off lever with block of wood and hammer, taking care not to damage finish on shift lever.
2) Remove rubber boot and floor pan cover. Remove shifter cap and remove shift lever from shifter housing.
1) Lubricate shift lever. Install shift lever in shifter housing, making sure that slot in lever aligns with tab in housing. Install shifter cap. Install rubber boot and floor pan cover.
2) Remove shift pattern insert from ball. Warm ball with heat gun to 140-180°F (60-80°C) and tap ball on lever with 7/16" socket and mallet. Install insert.
1) Mount transmission assembly in holding fixture and remove drain and filler plugs, collecting oil for recycling. Place gearshift lever in Neutral position. Remove shift control cover bolts,
2) Remove cover by lifting and rotating slightly counterclockwise to provide clearance for shift forks. Remove cover and discard gasket. See Fig. 5.
3) On 2WD, lock transmission in 2 gears. Remove yoke nut and yoke. Remove extension housing and slide speedometer drive gear mainshaft. On 4WD, remove extension housing nuts and housing, and discard gasket.
4) Measure and record synchronizer outer stop ring and 3rd gear endplay for reference during reassembly. See Fig. 15.
5) Remove input shaft bearing retainer and gasket. Rotate gear to align notch in input shaft gear clutch teeth with countershaft drive gear teeth.
6) Remove input shaft assembly and tapered roller bearing. Remove snap ring, washer and pilot roller bearing from recess in rear of input shaft. See Fig. 2
7) Place brass drift in front center of mainshaft and drive mainshaft to rear. Remove rear bearing with puller. Move mainshaft to rear and tilt front of mainshaft upward.
8.) Remove roller-type thrust bearing. Remove synchronizer and stop rings separately. Remove mainshaft assembly. See Figs. 3 and 4.
9) Remove reverse idler shaft bolt and retainer plate. Use brass drift at angle to drive idler shaft to rear. Remove shaft and lift reverse idler gear from case.
10) Remove bearing retainer from rear of countershaft. Roller bearing remains with retainer. Tilt cluster gear assembly and work out of case. Use driver to remove front bearings from case.
COMPONENT DISASSEMBLY & REASSEMBLY
SHIFT CONTROL COVER
Gearshift housing should be disassembled only if it is necessary to replace rails, poppets, interlock plungers, broken springs or If shift forks or cover itself need replacing.
1) Using No.2 screw extractor, remove roll pins from 1 st-2nd shift fork and gate. Push shift rail out through front to force plug out of housing. See Fig. 5. Cover detent ball hole to prevent ball and spring from flying out. Remove rail, fork and gate.
2) Remove back-up light switch. Remove remaining shift rails in same manner. Compress reverse gear plunger and remove retaining clip. Withdraw plunger and spring from gate.
Cleaning & Inspection
1) Examine housing for cracks or other damage. Inspect shift forks for wear and/or distortion. Check detent ball springs for distortion or collapsed coils.
2) Examine detent balls for corrosion and wear. If shift lever shaft detents show signs of wear, replace them. Replace all gaskets, expansion plugs and roll pins. See Fig. 10.
1) Place spring on reverse gear plunger, install and compress assembly in reverse shift gate. Install retaining clip. Start reverse shift rail in cover. Place detent spring and ball in position, depress ball and slide shift rai1 over it.
2) Install gate and shift fork on rail and install new roll pins. Apply film of sealer to plug, seat at front of cover. Install new plug in reverse shift rail bore.
3) Place reverse fork in neutral position and install 2 interlock plungers in bores. Insert interlock pin in 3rd-4th shift rail. Install remaining rails in same manner as reverse rail, making sure that interlock plunger in 1st-2nd shift rail is in place.
4) Install back-up light switch. Install new expansion plugs and rail interlock hole plug (if equipped).
INPUT SHAFT DRIVE GEAR
Remove tapered roller bearing from pinion shaft with puller. Remove snap ring, pilot roller bearing washer: and pilot bearing rollers from gear. Remove bearing race from front bearing retainer with puller. Remove pinion shaft seal.
1) Position drive pinion in arbor press. Place wooden block on pinion gear and press bearing until it contacts bearing inner race. See Fig. 7.
2) Lubricate pilot bearing rollers with light grease and insert in cavity at rear of drive pinion gear. Install washer and snap ring. Press new seal into place with lip of seal toward mounting surface. Press bearing race into retainer.
Roller Bearing Race
Bearing race is installed in bearing retainer. Use puller to remove race from retainer. Press new race squarely into retainer. See Fig. 8.
Oil Seal Replacement
Pry oil seal out of retainer and press new seal into place using sleeve. Lip of oil seal should point toward gasket surface of retainer.
Remove clutch gear snap ring. Remove clutch gear, synchronizer outer stop ring-to-3rd gear shim(s) and 3rd gear. Remove split lock ring with 2 screwdrivers. Withdraw 2nd gear & synchronizer assy. Remove 1st-Reverse sliding gear from shaft.
1) Place mainshaft assembly in soft-jawed vise with rear end up. Install 1st-reverse gear making sure 2 spline springs are in place inside gear as it is installed on shaft.
2) Move mainshaft in vise so that forward end is up. Install synchronizer spring and synchronizer on 2nd gear. Secure with snap ring, making sure snap ring tangs are away from gear. Slide 2nd gear assembly onto mainshaft making sure synchronizer is toward rear. Secure gear to shaft, with split lock snap rings, then install 3rd gear. Synchronizer clutching gear must be installed with BOTH oil slots facing 3rd gear. Oil slots must NOT face thrust bearing.
4) Install correct shim(s) between 3rd gear and 3rd-4th synchronizer stop ring. Refer to endplay measurement obtained during disassembly to bring endplay within specification. Exact determination of endplay will be made after mainshaft and main drive gear are installed in case.
REVERSE IDLER GEAR
Gear is serviced by assembly replacement only.
Replacement gear is equipped with integral bearings rather than bushing as on original gear. Do not attempt to disassemble roller bearing assembly. Bearing lock ring cannot be removed without damaging gear or bearing.
Press or drive old bearing out of case and discard. Install new bearing, pressing bearing cage into case until flush with front of case. Coat roller bearings with multipurpose grade 2 grease.
Using puller, remove rear bearing from retainer and discard. Position new bearing squarely in retainer bore and press into place until bearing bottoms in retainer. Coat roller bearings with multipurpose grade 2 grease.
CLEANING & INSPECTION
1) All parts should be thoroughly washed in cleaning solvent and air-dried. Remove portions of old gaskets with stiff brush or scraper. Clean bearings separately from other parts. Hold bearing races so bearings will not rotate and brush with soft brush to remove all foreign material.
2) Loose particles may be removed by striking bearing flat against wood block. Rinse bearings in clean solvent and air dry. Lubricate with light grade oil and wrap in clean paper until ready to reinstall. Do not spin bearings.
3) Examine all gear teeth and splines for chips, wear, breaks or nicks. Examine case, housing, retainers and covers for cracks or other damage. Inspect thrust washers, snap ring grooves, & spacers for wear or damage.
1) Press front countershaft roller bearing into case until cage is flush with front of case. Lubricate roller bearings with light coating of grease. Place transmission with front of case facing down. If uncaged bearings are reused, hold loose rollers in place with light film of grease.
2) Lower countershaft assembly into case placing thrust washer tangs in slots in case and inserting front end of shaft into bearing. Install countershaft gear rear thrust bearing and race on pilot diameter of countershaft.
See Fig. 12.
3) Install new rear bearing retainer gasket, rear bearing retainer and bearing assembly. Install bolts and tighten. Install reverse idler gear assembly in transmission case. Align reverse idler shaft so lock plate groove in shaft is in proper alignment to install lock plate.
4) Hold gear in position and tap shaft through case and gear. Install lock plate and washer. Tighten bolt. Ensure that gear turns freely on shaft. Lower rear end of mainshaft into case (holding 1st gear on shaft) and maneuver through rear bearing opening. Ensure that synchronizer and shims remain in position on mainshaft. Install roller thrust bearing. See Fig. 13.
5) Place block of wood between front end of mainshaft and front of case. Install rear bearing on mainshaft and drive into case until bearing snap ring is flush with case. Install rear extension housing on transmission.
6) With cutaway portion of clutch teeth in facing downward on input shaft, install gear into case. Install input shaft bearing retainer without gasket or retaining bolts. Hold shaft and retainer in line. Measure clearance between retainer and case. See Fig. 11.
7) Install .010-.015" (.254-.381 mm) larger shim pack than measured clearance. Install between retainer and case. This will provide the correct amount of input shaft endplay. See TRANSMISSION SPECIFICATIONS chart. Install and tighten retaining bolts and recheck endplay using a dial indicator. See Fig. 14.
8.) After endplay has been correctly set, recheck synchronizer clearance. See TRANSMISSION SPECIFICATION chart for synchronizer clearance specifications. See Fig. 15. Adjust if required. Lubricate extension housing bushing, seal and "U" joint flange. Install speedometer drive gear flange and tighten attaching nut.