Hi all,

Is there a way to test a diff that is not in a car? Just spin it and see that it spins smoothly?

I found a used diff which is claimed to be in good working order so I figured I would buy it as a spare but don't want to be hosed.

 

The input shaft (where the propshaft connects to) should have NO axial / radial play.
The output shafts have a little radial play = normal.

Drain the oil, look for metal bits.
If the oil comes out black it hasn't been changed in a while.
Check the magnetic drain plug for big metal shavings.

It takes 3 hands: turn the input shaft and slip/hold the 2 output shafts, you should feel no crunches.
Also, hold the input and turn one output, the other output should turn the other direction.
Turning a cold diff on a bench by hand is hard though.
Even more if its still filled with thick oil.

All-the-way:
Pop out the output shafts and remove the back cover.
Look at the wear marks on the ring gear, check for missing pinion/ring teeth.
You'll need some liquid gasket to put the cover back on.

Note: there is a difference between '00-'03 and '04-now input flanges.
The holes are bigger in later models.
Swapping an input flange is possible but the officail way is to take the diff apart.
Swapping it ghetto-style is risky IMO.

 

What he said^^^^

 

Yeah! I agree as well.

 

some top tips for my first inspection of the differential...

any chance of maybe stickying this info... could be helpful for future members...?