We dismantle the flange of the elastic coupling from the toe of the output shaft (see Replacing the output shaft seal) …
...and reverse light switch (see Replacement of the switch of lanterns of a backing).
The gear selector mechanism can be dismantled on the vehicle without removing the gearbox. For clarity, these operations are performed on the removed gearbox.
Remove the cuff of the gear selection mechanism.
Set the gear lever to the neutral position.
head «on 10» unscrew the three nuts securing the gear lever housing..
... and take out the gear selection mechanism.
The connection is sealed with a gasket.
With a marker we mark the relative position of the washers and the guide plate of the mechanism.
head «on 10» unscrew the two nuts securing the reverse locking plate, holding the bolts with a wrench of the same dimension,..
... and remove the blocking plate.
Loosen one more nut...
... remove the bottom washer of the guide plate.
Having taken out one guide bar with two springs,..
... remove the guide plate from the lower end of the lever.
Remove the top washer of the guide plate.
Remove the shift lever housing.
We take out the rubber sealing rings of the bolts from the grooves of the housing.
Remove the bottom gasket of the ball joint housing.
We remove the flange with a protective cover..
...and the upper body gasket.
Remove the retaining ring with pliers.
Remove the washer and spring.
We remove the spherical washer..
... and disconnect the lever and the ball joint housing.
We install the gearbox with the clutch housing on the workbench.
head «on 10» unscrew the ten nuts securing the lower cover of the gearbox.
Taking off the lid..
...and a gasket.
Using a screwdriver, through the hole in the gear selection mechanism, we move down the stem of the I-II gear fork (2nd gear is engaged).
key «at 13» unscrew the rear cover fastening nut located inside the box body.
key «at 13» unscrew the five nuts securing the rear cover located outside the case.
We tap with a hammer on the tides of the cover, while using a screwdriver (or a suitable piece of pipe with the output shaft seal removed) hold the rear bearing on the output shaft.
Slide the cover off the studs and remove by turning it clockwise (viewed from the side of the output shaft shank), to prevent the cover from touching the rods and the gear unit of the 5th gear and reverse.
Remove the cover gasket.
To replace the bearing of the gear unit of the 5th gear and reverse…
... pry the bearing rollers with a screwdriver...
... and remove the rollers from the separator.
We take out the separator.
Hook the outer race of the bearing..
... take it out of the back cover slot.
Remove the thrust ring of the rear bearing of the secondary shaft.
Remove the bearing outer ring with cage and rollers.
Remove the bearing inner race.
Removing the spacer..
...and an oil slinger.
To stop the shafts from turning, two gears must be engaged. 2nd gear was engaged when the back cover was removed. Before turning on reverse or V gears, we release the fork for engaging these gears. For this…
... the key «on 10» unscrew the bolt securing the fork to the stem.
By pressing the screwdriver on the fork down, we turn on the reverse gear.
ring wrench (head) «at 17» unscrew the bolt securing the gear unit of the V gear and reverse.
Removing the bolt..
... and remove the gear block from the splines of the intermediate shaft.
We clamp the V gear and reverse gear unit in a vise with soft metal jaw pads.
Using two screwdrivers, we compress the inner ring of the bearing of the gear block..
... and remove the inner ring.
Remove the 5th gear bushing..
... the gear itself with the synchronizer blocking ring,...
... hub..
...and a synchronizer clutch.
By turning the fork for engaging the V gear and reverse gear on the rod to the secondary shaft,..
... remove the intermediate reverse gear.
ring wrench «at 13» unscrew the two bolts securing the cover of the clamps.
Remove cover and gasket.
Removing the retainer springs (the spring of the rod of the V gear and reverse is longer than the other two and has a dark color of the coating).
Using a magnetized screwdriver, remove all three latches.
We take out the rod for engaging V gear and reverse gear with a fork.
We remove the fork from the stem.
With a magnetized screwdriver, we take out the locking cracker from the hole in the gearbox housing, which is located between the crankcase slots for the rods of the V gear and reverse and III-IV gears.
Remove the reverse gear from the output shaft.
We take out the key from the groove of the shaft.
head «on 10» we turn off the bolt of fastening to the rod of the fork of inclusion of III–IV gears.
We take out the stock.
A blocking cracker is inserted into the stem hole,..
... we take it out.
With a magnetized screwdriver, we take out the locking cracker from the hole in the gearbox housing, which is located between the housing nests for the rods of I–II and III and IV gears (this cracker is noticeably longer than the cracker located between the engagement rod of the 5th gear - reverse and the engagement rod of the III-IV gears).
head «on 10» we turn off the bolt of fastening to the rod of the fork of inclusion of I-II gears.
We take out the stock.
Using an impact screwdriver with a Phillips tip, we unscrew the three screws securing the lock plate of the intermediate bearing of the secondary shaft.
The screws are secured with special washers.
Remove the stop plate.
ring wrench «at 19» unscrew the nut securing the axis of the intermediate reverse gear, holding the axis from turning with a wrench «at 24».
Remove the reverse intermediate gear shaft.
Loosen the nuts securing the clutch housing (see Replacing the input shaft seal),...
... we share clutch and gearbox housings.
We remove the lining.
We remove the spring washer with a conical surface from the input shaft (with a smaller diameter it faces the bearing).
We clamp the splined part of the input shaft into a vice with soft metal jaw pads.
ring wrench «at 19» unscrew the bolt of the clamping washer of the front bearing of the intermediate shaft.
Remove the bearing retainer.
With two screwdrivers, we pry the front double-row bearing of the intermediate shaft by the adjusting ring..
... and remove the bearing.
When the bearing is removed, its rear inner ring may remain on the shaft.
Use two screwdrivers to compress the rear inner ring of the bearing..
...and 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 gear of the 1st gear of the intermediate shaft, we shift the rear bearing.
We take out the outer ring of the bearing with the cage and rollers.
Remove the bearing inner race from the shaft end.
By moving the intermediate shaft back,..
... we take it out of the gearbox housing.
Prying with two screwdrivers for the adjusting ring the rear bearing of the input shaft,..
... we take out the input shaft assembly with the bearing and the synchronizer blocking ring.
Loosen the retaining ring with pliers..
...and take it off.
Remove the spring washer.
We rest the end face of the outer ring of the bearing on the vise jaws.
With a hammer with a plastic striker, we strike at the end of the input shaft..
... and compress the bearing.
Unclip the adjusting ring with tongs..
...and take it off.
Having shifted the synchronizer blocking ring, we open the retaining ring with tongs..
...and take it off.
Removing the blocking ring..
...and a synchronizer spring.
Blocking rings of synchronizers of other gears are removed similarly.
Remove the needle bearing from the front toe of the secondary shaft.
We remove the forks of inclusion of I and II, III and IV gears.
Using two screwdrivers, we pry the intermediate bearing of the secondary shaft by the adjusting ring..
...and take it off.
Having tilted, we remove the secondary shaft assembly from the gearbox housing with gears, couplings, hubs and synchronizer blocking rings.
We remove the bushing and gear of the 1st gear assembly with the blocking ring from the rear side of the shaft.
We take out the bushing from the gear.
We remove the clutch of the synchronizer for switching on I and II gears.
Remove the synchronizer hub.
Remove the 2nd gear gear assembly with the blocking ring.
From the front end of the output shaft, remove the synchronizer clutch of III and IV gears.
Clamping the secondary shaft in a vise with soft metal jaws,..
... use pliers to remove the retaining ring.
Removing the spring washer (it is installed with the convex side towards the front end of the shaft).
Remove the hub of the synchronizer of III and IV gears...
... and the third gear gear assembly with the synchronizer blocking 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..
... carefully remove the separator with balls with a screwdriver..
... and put it on the inner ring (removed from the shaft).
The separator with balls and the inner ring is inserted into the outer ring of the bearing.
When assembling the input shaft..
... with a suitable piece of pipe we press the bearing onto the shaft, relying on its inner ring.
After installing the secondary and intermediate shafts into the crankcase of the gearbox, we press in the front and rear bearings of the intermediate shaft, the intermediate bearing of the secondary shaft and the inner ring of the gear block bearing.
The outer ring of the bearing of the gear unit of the 5th gear and reverse…
... we press in with a tool head of a suitable size (pipe section) into the slot on the back cover.
We insert a separator and rollers into the outer ring of the bearing.
To prevent loosening of the bolt for fastening the gear unit of the 5th gear and reverse gear, we apply thread sealant to the thread of the bolt.
For ease of installation of the rear cover, we install the rear bearing assembly on the secondary shaft.
It is advisable to lubricate all gaskets with a thin layer of silicone sealant.
When assembling the gear selection mechanism, apply Litol-24 grease to the ball joint.