Disassembly of the gearbox was considered in the article - How to disassemble the gearbox of a Gazelle Next car.
In this article, we will consider how to properly assemble and adjust the gearbox of the rear axle of a Gazelle Next car
We assemble the main gear in the reverse sequence to disassembly, lubricating the bearings and gears with transmission oil.
Having installed the drive gear in the gearbox housing, tighten the flange nut with a torque of 16–20 kgfm with a torque wrench, while the gear must be turned to correctly install the rollers in the bearings.
We install an indicator with a graduation value of not more than 0.01 mm on a tripod, resting its leg against the end of the flange and moving the shaft behind the flange, measure the axial play of the drive gear.
To eliminate the backlash, we take out the spacer ring installed on the gear shaft and measure its thickness with a micrometer.
We select and install a new spacer ring. It should be thinner than the removed backlash and an additional 0.05 mm thinner if the pinion bearings are new, or 0.01 mm if the bearings are the same.
In the absence of axial play of the drive gear, we check the torque of resistance to the rotation of the shaft with a special torque wrench with a division value of up to 0.5 kgfm.
With the correct adjustment, the moment of resistance should be 15–20 kgfcm for new bearings or 7–10 kgfcm if the bearings are the same.
With sufficient accuracy, the moment of resistance can be measured with a household steelyard by hooking its hook over the hole in the flange. In this case, the required values will be less - 3.8–5 kgf and 1.8–2.5 kgf, respectively.
If the moment of resistance is greater, we change the spacer ring to another one, thicker by 0.01–0.02 mm, if it is less, we accordingly select a ring of smaller thickness.
The bolts of fastening parts of the differential box and the bolts of the driven gear, as well as their threaded holes, are degreased and covered with an anaerobic sealant before assembly.
We pay special attention to the cleanliness of the end faces of the gears and the gearbox of the satellites, the slightest dirt or nicks are unacceptable.
When installing the driven gear on the satellite box, we center it using long M10x1 bolts (bolts from old connecting rods can be used).
Using the adjusting nuts, we tighten the differential bearings with a slight preload, while turning the gear in one direction or the other so that the bearing rollers take the correct position.
To measure the lateral clearance in the meshing of the main gears on the rear axle housing, we fix the indicator by bringing its probe to the top of the tooth on the outside of the driven gear.
The gap should be 0.15–0.20 mm. The measurements should be repeated on at least six teeth in opposite areas of the rim.
To reduce the gap (with a screwdriver or a thin steel rod), loosen the adjusting nut on the side opposite the driven gear, and tighten the other.
Unscrew one nut and tighten the other by the same amount, focusing on the grooves of the adjusting nuts.
In this case, each unscrewing of the adjusting nut must be completed by slightly tightening it.
For example, to loosen a nut five notches, unscrew it six and then tighten one notch.
This will ensure that the outer ring of the bearing is in constant contact with the nut, thereby ensuring that it is secured during operation.
To increase the gap, repeat the entire procedure in reverse order.
After adjusting the lateral clearance in the engagement, we check the axial play in the differential bearings, for which we fix the indicator on the tripod, resting its probe against the end of the driven gear.
Swinging the gear in the axial direction, we measure the backlash in the differential bearings.
Using the adjusting nut located on the opposite side of the driven gear, we set the axial play 0.035–0.055.
Further, tightening the nut, set the bearing preload: 0.1 - when the bearings run less than 10 thousand km; 0.05 - with a run of more than 10 thousand km.
Turning the nut one groove corresponds to "compression" of the bearing by 0.03 mm.
After adjusting, tighten the bearing cap bolts and install the lock plates and re-check the side clearance.
Adjustment of the main gear according to the contact patch of the teeth
Before the final tightening of the cover bolts, turn them out one by one and apply an anaerobic sealant to the threaded part.
Adjusting the final drive according to the contact patch of the teeth is an effective way of adjusting the gear engagement.
It also allows you to check the quality of adjustments made in other ways.
Apply paint, preferably a bright one, to the teeth of the driven gear.
We rotate the drive gear flange several times in both directions, at the same time slowing down the driven gear until the paint abrades at the contact points of the teeth.
We examine the contact spots on the teeth of the driven gear from the convex and concave sides.
If the contact patch is located at the top of the teeth, it is necessary to increase the thickness of the adjusting ring at the pinion gear, and if at the base, reduce it.
If the contact patch is displaced to the center of the gear, it is necessary to increase the gap between the driven and driving gears, and if outward, to reduce.
After adjustment, we install the gearbox in the rear axle, while applying a thin layer of oil-resistant sealant to the mounting bolts and flange.
Having assembled the rear axle and filled it with oil, we test the gearbox on the go.
To do this, we make a trip at a speed of 60–70 km / h for 20–30 minutes.
Heating of the crankcase throat should not exceed 95 ° (water droplets should not boil).
Otherwise, it is necessary to reduce the preload of the pinion bearings.