Do-it-yourself GAZelle gearbox adjustment

2024 Author: Erin Ralphs | [email protected]. Last modified: 2024-02-19 11:42

The well-known phrase about the impermanence of everything that exists under the Moon immediately pops up in the head of the owner of the GAZelle, as soon as his ear catches an extraneous rumble somewhere from below when the car is moving. Most often this is observed when driving at a speed of at least 30 km / h.

An experienced driver will immediately determine the cause of the “extraordinary” sound: the rear axle, the GAZelle gearbox needs to be adjusted. But the devil is not as terrible as he is painted. Extraneous hum is completely eliminated, and with our own hands.

This is serious

Doing "freelance" sound should be done immediately, as delay is like death (reducer). Violation of the mode of interaction of gears will lead to their rapid wear and damage to the gearbox. You should not postpone the problem indefinitely, you should immediately begin to fix it.

Of course, not a simple matter - gear adjustmentrear axle ("GAZelle" - a completely repairable car with your own hands, as you know). Therefore, one must be prepared that the first results may not be as expected.

But do not despair in case of unsuccessful adjustment, but you need to read the "Operation and Repair Manual" once again and repeat everything from the beginning.

Where to start

Adjusting the GAZelle gearbox will first of all require you to perform a banal operation - draining the transmission oil.

First of all, you need to heat the oil in the gearbox. To do this, you can drive a car or, by raising the rear axle on jacks or a lift, start the car and shift into gear. This is necessary to properly drain the oil from the gearbox.

Draining the oil into some commensurate container, you should immediately inspect it for the presence of metal chips. The presence of metal in the oil indicates wear on the gears of the gearbox and the need to replace them with subsequent adjustment of the gearbox.

Convinced of the need to repair the gearbox, remove it and disassemble it. If there are shells, chips and other defects on the parts of the mechanism, then such parts must be replaced, and the gearbox must be adjusted.

Adjusting the bearing clearance

Adjustment of the GAZelle gearbox is done after the final assembly of the mechanism. Having assembled the gearbox, you can begin to adjust it.

For the convenience of carrying out adjustment work, we install the assembled gearbox on the stand and fix the bearing yokes with a force of up to 9 kgf. Then with a special key (plate, possibly withwith a welded centering sleeve and a handle) we adjust the thermal gap in the bearings: we tighten the front yoke nut until it stops, and then loosen it by 3 mm (the distance is well determined by a special movement indicator).

Adjustment can be made without using the movement indicator. In this case, the yoke nut is tightened to the stop, and then released by one slot in it. The nut should turn freely by hand.

This is enough to create a bearing clearance.

Adjusting the engagement of the planetary gear with the shank

The clearance between planetary gear and shank needs to be set. To do this, make a mark on the yoke against the cutout of the yoke nut. We install the movement indicator on the "planetary" and, turning the gearbox shank, determine the desired gap. Its value should be 0.15-0.18 mm.

If the gap is large, then do the following:

• unscrew the front bearing yoke nut one notch from the mark made before;
• rear bearing yoke nut is tightened by one notch;
• check the gap obtained after adjustment;

If loosening the nut by one notch did not lead to the desired clearance, adjust the nuts for one more notch. This is done until the required clearance between the shank and the planetary is reached. After that, install the clamps onyoke nuts.

Such actions do not violate the adjustment of the differential temperature gap, which, in turn, will not cause the gearbox to overheat in the future.

Checking the quality of the adjustment on the stand

The tooth contact patch is a sure way to correctly determine how well the adjustment of the rear axle gearbox is carried out in any car (GAZelle is no exception).

To do this, the driven gear (its teeth) are painted with bright paint.

Then you should rotate (repeatedly and in both directions) the drive gear by the flange, slowing down the driven gear. This operation is done before removing the paint in the areas of contact between the teeth (the appearance of a contact patch).

The location of the spot will tell you the flaws in the adjustment made earlier.

If it is at the top of the teeth, then you should put a thicker pinion ring. But if the stain is located at the base of the tooth, then the thickness of this ring should be reduced.

In the case when the stain is on the narrow end of the tooth, increase the distance between the drive and driven gears. If the spot is observed at the wide end, then this gap must be reduced.

If the spot is in the right place, then this means that the adjustment of the rear gearbox has been successfully completed, the GAZelle is now ready for practicalchecking the quality of the performed adjustment work. Going on a short trip to make sure there is no "extraordinary" noise.

Checking the quality of adjustment in motion

After the GAZelle gearbox is adjusted, its quality should be checked practically, on the go. Do not forget to pour the oil prescribed by the "Operation and Repair Manual" into the axle gearbox.

Checking is carried out on the move, the speed should be about 60-70 km / h, the duration of the trip is 20-30 minutes. An indicator of the quality of the adjustment will be the crankcase heating temperature - no more than 95 degrees Celsius.

Take care of your gearbox

In order for the rear axle gearbox to work out its resource, it is necessary to operate it carefully and competently.

First of all don't:

• overload the car, especially in hot weather;
• pretend to be Schumacher and make sharp starts;
• overcome long climbs in one fell swoop - this will lead to overheating of the gearbox;
• fill any oil into the gearbox crankcase, as well as violate the frequency of its change: in summer - every 35 thousand km, in winter - after 40 thousand km.
• forget to check shank play at every oil change. If it is found, it should be eliminated immediately;

By the way, the adjustment of the steering gear ("GAZelle" means) is carried out according to a similar technology.