Chevrolet Cobalt Service & Repair Manual: Drive Axle Assembly Leak, Inspection
| A visual inspection must always
be performed to confirm the presence of aftermarket components, potential
collision damage, or areas of concern. |
| A rear-axle oil leak is easy to
miss. The axle works normally until it suddenly seizes up, the expensive
and possibly dangerous result of it running dry of oil. |
| The clearest sign of a leak is
oil on the ground under the vehicle. Oil leaks from the hub oil seals of
a live rear axle, may also leave traces on the inner surfaces of the wheels,
or even get into the brakes. |
| Always clean drive axle assembly
before starting the inspection. The origination of a leak can be narrowed
down considerably during cleaning. |
| Axle oil is thick when cold and
unlikely to drip out of a very small opening, but it flows freely when warm
after a run. Any drip marks will probably be where you first parked the
car after returning from a run. Within an hour the oil thickens as it cools
and stops dripping. |
| You should also inspect the oil
level, generally every 6,000 miles. |
| Some vehicles have "sealed for
life" axles whose oil never needs changing. These axles do not have a drain
plug. But they, too, can leak and need refilling, which is done through
the plug hole by which they were filled originally. |
| 1. |
Drive vehicle until axle reaches operating
temperature. |
| 2. |
Raise and support vehicle using a suitable
lift. |
| 3. |
Inspect axle vent or vent tube for
leakage. Minor seepage around this area is normal. |
| 4. |
Inspect drain plug for leakage if equipped. |
| 5. |
Inspect fill plug for leakage. |
| 6. |
Inspect differential housing cover
gasket area for leakage. |
| 7. |
Inspect pinion yoke oil seal for leakage. |
| 8. |
Inspect for axle housing porosity. |
| 9. |
On models equipped with independent
rear suspension, inspect axle shaft oil seals for leakage. |
| 10. |
On models without independent rear
suspension, proceed as follows: |
| |
a. |
Inspect axle tube to differential carrier
housing joint for leakage. |
| |
b. |
Remove wheel and tire assemblies. |
| |
c. |
Inspect axle shaft oil seal for leakage.
Wheels or brake components may show signs of contamination. |
| 11. |
On all models, once leak has
been detected repair system as required. |
|
Disassembly
When pinion gears are removed,
place final drive carrier into a clean transmission oil pan in order to
prevent losing needle bearings.
1.
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Differential, Overhaul
Electrical