We dismantle the flange of the elastic coupling from the nose of the secondary shaft (see Replacing the secondary shaft seal)…
…and the reversing light switch (see Replacing the reverse light switch).
The gear selection mechanism can be dismantled on the vehicle without removing the gearbox. For clarity, these operations are performed on a removed gearbox.
We remove the gear selection mechanism cuff.
We set the gear shift lever to neutral position.
Using a 10 mm socket, unscrew the three nuts securing the gear shift lever housing…
…and we take out the gear selection mechanism.
The connection is sealed with a gasket.
Using a marker, mark the relative positions of the washers and the guide plate of the mechanism.
Using a 10 mm socket, unscrew the two nuts securing the reverse gear locking plate, holding the bolts with a wrench of the same size,…
…and remove the locking plate.
After unscrewing one more nut,...
…remove the lower washer of the guide plate.
By removing one guide bar with two springs,…
…remove the guide plate from the lower end of the lever.
Remove the upper washer of the guide plate.
We remove the gear shift lever housing.
We remove the rubber sealing rings of the bolts from the grooves of the housing.
We remove the lower gasket of the ball joint housing.
We remove the flange with the protective cover..
…and the upper housing gasket.
We remove the retaining ring using pliers.
We remove the washer and spring.
We remove the spherical washer..
…and we separate the lever and the ball joint housing.
We install the gearbox with the clutch housing on the workbench.
Using a 10 mm socket head, unscrew the ten nuts securing the lower gearbox cover.
We remove the lid..
…and a sealing gasket.
Using a screwdriver, move the rod of the fork for engaging I–II gears down through the hole in the gear selection mechanism (in this case, the second gear is engaged).
Using a 13 mm spanner, unscrew the rear cover mounting nut located inside the gearbox housing.
Using a 13 mm spanner, unscrew the five nuts securing the rear cover, located on the outside of the case.
We tap the lid lugs with a hammer, while using a screwdriver (or with a suitable piece of pipe with the secondary shaft seal removed) we hold the rear bearing on the secondary shaft.
We move the cover off the studs and remove it by turning it clockwise (looking from the secondary shaft tailstock), to prevent the cover from touching the rods and the block of gears of the 5th gear and reverse gear.
We remove the cover gasket.
To replace the bearing of the 5th gear and reverse gear block…
…we pry up the bearing rollers with a screwdriver...
... and remove the rollers from the separator.
We remove the separator.
By hooking the outer ring of the bearing,…
…we remove it from the socket on the back cover.
Remove the thrust ring of the secondary shaft rear bearing.
We remove the outer bearing ring with the separator and rollers.
We remove the inner bearing ring.
We remove the spacer sleeve..
…and an oil deflector washer.
To lock the shafts from turning, it is necessary to engage two gears. The 2nd gear was engaged when the rear cover was removed. Before engaging the reverse or 5th gear, we release the fork for engaging these gears. To do this…
…using a 10 mm spanner, unscrew the bolt securing the fork to the stem.
By pressing the fork down with a screwdriver, we engage reverse gear.
Using a 17 mm open-end wrench (head), unscrew the bolt securing the 5th gear and reverse gear block.
We take out the bolt..
…and remove the gear block from the splines of the intermediate shaft.
We clamp the block of gears of the 5th gear and reverse gear in a vice with soft metal jaw pads.
Using two screwdrivers, press off the inner ring of the gear block bearing…
…and remove the inner ring.
We remove the 5th gear bushing,…
…the gear itself with the synchronizer locking ring,...
…hub…
…and the synchronizer clutch.
By turning the fork for engaging the 5th gear and reverse gear on the rod towards the secondary shaft,…
…we remove the intermediate gear of the reverse gear.
Using a 13 mm open-end wrench, unscrew the two bolts securing the clamp cover.
We remove the cover and gasket.
We take out the retainer springs (the spring of the V gear and reverse gear rod is longer than the other two and has a dark color coating).
Using a magnetized screwdriver, remove all three fasteners.
We take out the rod for engaging the 5th gear and reverse gear with the fork.
We remove the fork from the rod.
Using a magnetized screwdriver, remove the locking cracker from the hole in the gearbox housing, which is located between the housing sockets for the 5th gear, reverse gear, and 3rd–4th gear rods.
We remove the driven gear of the reverse gear from the secondary shaft.
We remove the key from the shaft groove.
Using a 10 mm head, unscrew the bolt securing the III–IV gear fork to the rod.
We take out the rod.
A locking cracker is inserted into the hole in the rod,…
…we take it out.
Using a magnetized screwdriver, remove the locking cracker from the hole in the gearbox housing, which is located between the housing sockets for the I–II and III–IV gear rods (this cracker is noticeably longer than the cracker located between the V gear–reverse gear rod and the III–IV gear rod).
Using a 10 mm socket, unscrew the bolt securing the 1st-2nd gear fork to the rod.
We take out the rod.
Using a Phillips-head impact screwdriver, unscrew the three screws securing the secondary shaft intermediate bearing retaining plate.
The screws are secured with special washers.
We remove the locking plate.
Using a 19 mm open-end wrench, loosen the nut securing the reverse intermediate gear axle, holding the axle from turning with a 24 mm wrench.
We take out the axle of the intermediate reverse gear.
After unscrewing the clutch housing mounting nuts (see Replacing the primary shaft seal),...
…we separate the clutch and gearbox housings.
We remove the gasket.
Remove the spring washer with a conical surface from the primary shaft (its smaller diameter faces the bearing).
We clamp the splined part of the primary shaft in a vice with soft metal jaw pads.
Using a 19 mm open-end wrench, unscrew the bolt of the clamping washer of the front bearing of the intermediate shaft.
Remove the bearing clamp washer.
Using two screwdrivers, pry up the front double-row bearing of the intermediate shaft by the mounting ring…
…and remove the bearing.
When removing a bearing, its rear inner ring may remain on the shaft.
Using two screwdrivers, press off the rear inner bearing ring…
…and we take it off.
We take out the thrust ring of the rear bearing of the intermediate shaft.
By inserting a screwdriver between the ends of the bearing and the 1st gear of the intermediate shaft, we move the rear bearing.
We take out the outer bearing ring with the separator and rollers.
We remove the inner bearing ring from the shaft nose.
By moving the intermediate shaft back,…
…we remove it from the gearbox housing.
Using two screwdrivers, pry the rear bearing of the primary shaft by the mounting ring,…
…we remove the primary shaft assembly with the bearing and synchronizer locking ring.
We use pliers to open the retaining ring..
…and we take it off.
Remove the spring washer.
We rest the end face of the outer bearing ring on the jaws of a vice.
Using a hammer with a plastic striker, we strike the end of the primary shaft..
…and press the bearing.
We use pliers to open the mounting ring..
…and we take it off.
Having moved the synchronizer locking ring, we use pliers to open the retaining ring..
…and we take it off.
We remove the blocking ring..
…and the synchronizer spring.
The synchronizer locking rings of other gears are removed in a similar manner.
Remove the needle bearing from the front end of the secondary shaft.
We remove the forks for engaging I and II, III and IV gears.
Using two screwdrivers, pry up the secondary shaft intermediate bearing by the mounting ring…
…and we take it off.
By tilting it, we remove the secondary shaft from the gearbox housing, complete with gears, couplings, hubs and synchronizer locking rings.
We remove the sleeve and the 1st gear gear assembly with the blocking ring from the rear side of the shaft.
We remove the sleeve from the gear.
We remove the synchronizer clutch for engaging 1st and 2nd gears.
We remove the synchronizer hub.
We remove the 2nd gear gear assembly with the blocking ring.
From the front end of the secondary shaft we remove the synchronizer clutch of the III and IV gears.
By clamping the secondary shaft in a vice with soft metal jaw pads,…
…we remove the retaining ring using pliers.
Remove the spring washer (it is installed with its convex side towards the front end of the shaft).
We remove the synchronizer hub of III and IV gears...
…and the third gear assembly with the synchronizer locking ring.
We assemble the gearbox in the reverse order.
If, when removing the front double-row bearing of the intermediate shaft, its rear inner ring remains on the shaft, then the bearing must be assembled before installation. To do this, from the outer ring of the bearing…
…we carefully remove the separator with balls using a screwdriver…
…and put it on the inner ring (removed from the shaft).
We insert the separator with balls and an inner ring into the outer ring of the bearing.
When assembling the primary shaft…
…using a suitable piece of pipe, we press the bearing onto the shaft, resting on its inner ring.
After installing the secondary and intermediate shafts into the gearbox housing, press in the front and rear bearings of the intermediate shaft, the intermediate bearing of the secondary shaft and the inner ring of the bearing of the gear block.
Outer ring of the bearing of the 5th gear and reverse gear block…
…we press it in with a tool head of the appropriate size (with a piece of pipe) into the socket of the back cover.
We insert the separator and rollers into the outer ring of the bearing.
To prevent the 5th gear and reverse gear block mounting bolt from loosening, apply thread sealant to the bolt threads.
For ease of installation of the rear cover, we install the rear bearing assembly on the secondary shaft.
It is advisable to lubricate all sealing gaskets with a thin layer of silicone sealant.
When assembling the gear selection mechanism, apply Litol-24 grease to the ball joint.