See Figure 1
- Remove drain bolt on transmission case and drain lubricant.
- Thoroughly clean the exterior of the transmission assembly.
- Using pin punch and hammer, remove roll pin attaching offset lever to shift rail.
- Remove extension housing-to-transmission case bolts and remove housing and offset lever as an assembly.
Do not attempt to remove the offset lever while the extension housing is still bolted in place. The lever has a positioning lug engaged in the housing detent plate which prevents moving the lever far enough for removal.
- Remove detent ball and spring from offset lever and remove roll pin from extension housing or offset lever.
- Remove plastic funnel, thrust bearing race and thrust bearing from rear of countershaft.
The countershaft rear thrust bearing, bearing washer and plastic funnel may be found inside the extension housing.
- Remove bolts attaching transmission cover and shift fork assembly and remove cover.
Two of the transmission cover attaching bolts are alignment-type dowel bolts. Note the location of these bolts for assembly reference.
- Using a punch and hammer, drive the roll pin from the 5th gearshift fork while supporting the end of the shaft with a block of wood.
- Remove 5th synchronizer gear snapring, shift fork, 5th gear synchronizer sleeve, blocking ring and 5th speed drive gear from rear of countershaft.
- Remove snapring from 5th speed driven gear.
- Using a hammer and punch, mark both bearing cap and case for assembly reference.
- Remove front bearing cap bolts and remove front bearing cap. Remove front bearing race and end play shims from front bearing cap.
- Rotate drive gear until flat surface faces countershaft and remove drive gear from transmission case.
- Remove reverse lever C-clip and pivot bolt.
- Remove mainshaft rear bearing race and then tilt mainshaft assembly upward and remove assembly from transmission case.
- Unhook overcenter link spring from front of transmission case.
- Rotate 5th gear-reverse shift rail to disengage rail from reverse lever assembly. Remove shift rail from rear of transmission case.
- Remove reverse lever and fork assembly from transmission case.
- Using hammer and punch, drive roll pin from forward end of reverse idler shaft and remove reverse idler shaft, rubber "O'' ring and gear from the transmission case.
- Remove rear countershaft snapring and spacer.
- Insert a brass drift through drive gear opening in front of transmission case and, using an arbor press, carefully press countershaft rearward to remove rear countershaft bearing.
- Move countershaft assembly rearward, tilt countershaft upward and remove from case. Remove countershaft front thrust washer and rear bearing spacer.
- Remove countershaft front bearing from transmission case using an arbor press.
- Remove thrust bearing washer from front end of mainshaft.
- Scribe reference mark on 3rd-4th synchronizer hub and sleeve for reassembly.
- Remove 3rd-4th synchronizer blocking ring, sleeve, hub and 3rd gear as an assembly from mainshaft.
- Remove snapring, tabbed thrust washer, and 2nd gear from mainshaft.
- Remove 5th gear with Tool J-22912-01 or its equal and arbor press. Slide rear bearing off mainshaft.
- Remove 1st gear thrust washer, roll pin, 1st gear and synchronizer ring from mainshaft.
- Scribe reference mark on 1st-2nd synchronizer hub and sleeve for reassembly.
- Remove synchronizer spring and keys from 1st-reverse sliding gear and remove gear from mainshaft hub. Do not attempt to remove the 1st-2nd-reverse hub from mainshaft. The hub and shaft are assembled and machined as a matched set.
DRIVE GEAR DISASSEMBLY
- Remove bearing race, thrust bearing, and roller bearings from cavity of drive gear.
- Using Tool J-22912-01 or its equal and arbor press, remove bearing from drive gear.
- Wash parts in a cleaning solvent.
- Inspect gear teeth and drive shaft pilot for wear.
DRIVE GEAR ASSEMBLY
- Using Tool J-22912-01 or its equal with an arbor press, install bearing on drive gear.
- Coat roller bearings and drive gear bearing bore with grease. Install roller bearings into bore of drive gear.
- Install thrust bearing and race in drive gear.
- Coat mainshaft and gear bores with transmission lubricant.
- Install 1st-2nd synchronizer sleeve on mainshaft hub aligning marks made at disassembly.
- Install 1st-2nd synchronizer keys and springs. Engage tang end of each spring in same synchronizer key but position open end of springs opposite of each other.
- Install blocker ring and 2nd gear on mainshaft. Install tabbed thrust washer and 2nd gear retaining snapring on mainshaft. Be sure washer tab is properly seated in mainshaft notch.
- Install blocker ring and 1st gear on mainshaft. Install 1st gear roll pin and then 1st gear thrust washer.
- Slide rear bearing on mainshaft.
- Install 5th speed gear on mainshaft using Tool J-22912-01 and arbor press. Install snapring on mainshaft.
- Install 3rd gear, 3rd-4th synchronizer assembly and thrust bearing on mainshaft. Synchronizer hub offset must face forward.
- Coat countershaft front bearing bore with Loctite 601, or equivalent, and install front countershaft bearing flush with facing of case using an arbor press.
- Coat countershaft tabbed thrust washer with grease and install washer so tab engages depression in case.
- Tip transmission case on end and install countershaft in front bearing bore.
- Install countershaft rear bearing spacer. Coat countershaft rear bearing with grease and install bearing using Tool J-29895 and sleeve J-33032, or its equivalent. The bearing when correctly installed will extend beyond the case surface 3mm.
- Position reverse idler gear in case with shift lever groove facing rear of case and install reverse idler shaft from rear of case. Install roll pin in idler shaft.
- Install assembled mainshaft in transmission case. Install rear mainshaft bearing race in case.
- Install drive gear in case, and engage in 3rd-4th synchronizer sleeve and blocker ring.
- Install front bearing race in front bearing cap. Do not install shims in front bearing cap at this time.
- Temporarily install front bearing cap.
- Install 5th speed-reverse lever, pivot bolt and retaining clip. Coat pivot bolt threads with nonhardening sealer. Be sure to engage reverse lever fork in reverse idler gear.
- Install countershaft rear bearing spacer and retaining snapring.
- Install 5th speed gear on countershaft.
- Insert 5th speed-reverse rail in rear of case and install in to reverse 5th speed lever. Rotate rail during installation to simplify engagement with lever. Connect spring to front of case.
- Position 5th gear shift fork on 5th gear synchronizer assembly and install synchronizer on countershaft and shift fork on shift rail. Make sure roll pin hole in shift fork and shift rail are aligned.
- Support 5th gear shift rail and fork on a block of wood and install roll pin.
- Install thrust race against 5th speed synchronizer hub and install snapring. Install thrust bearing against race on countershaft. Coat both bearing and race with petroleum jelly.
- Install lipped thrust race over needle-type thrust bearing and install plastic funnel into hole in end of countershaft gear.
- Temporarily install extension housing and attaching bolts. Turn transmission case on end, and mount a dial indicator on extension housing with indicator on the end of mainshaft.
- Rotate mainshaft and zero dial indicator. Pull upward on mainshaft until end play is removed and record reading. Mainshaft bearings require a preload of 0.025-0.130mm. To set preload, select a shim pack measuring 0.025-0.130mm greater than the dial indicator reading recorded.
- Remove front bearing cap and front bearing race. Install necessary shims to obtain preload and reinstall bearing race.
- Apply a 1 / 8 in. bead of RTV sealant, #732 or equivalent, on case mating surface of front bearing cap. Install bearing cap aligning marks made during disassembly and torque bolts to specification.
- Remove extension housing.
- Move shift forks on transmission cover and synchronizer sleeves inside transmission to the neutral position.
- Apply a 1 / 8 in. bead of RTV sealant, #732 or equivalent, on cover mating surface of transmission
- Lower cover onto case while aligning shift forks and synchronizer sleeves. Center cover and install the 2 dowel bolts. Install remaining bolts and torque to specification. The offset lever to shift rail roll pin hole must be in the vertical position after cover installation.
- Apply a 1 / 8 in. bead of RTV sealant, #732 or equivalent, on extension housing to transmission case mating surface.
- Install extension housing over mainshaft and shift rail to a position where shift rail just enters shift cover opening.
- Install detent spring into offset lever and place steel ball in neutral guide plate detent. Position offset lever on steel ball and apply pressure on offset lever and at the time seat extension housing against transmission case.
- Install extension housing bolts and torque to specification.
- Align and install roll pin in offset lever and shift rail.
- Fill transmission to its proper level with lubricant.