Rear end

[Bulldog]

Did a rebuild on my 8.8 rearall new bearings etc. after break in noticed some slack at the opinion flange how much is ok ? Set up went well everything seemed fine rear very quite .just wondering how much slack is ok thanks Bulldog.

[eschaider]

Where did you set the pinion depth and the backlash?


Ed

[Grubby]

There is noticeable backlash in a correctly setup differential. That is the clunk you hear when you go from drive to reverse in your daily driver.

My Dana 44 manual shows .005"-.008" backlash.

John

[Bulldog]

Edthanks for reply, opinion depth I can't ember shim thickness but backlash was about 8thousand.just seems like flange has some play in it it did t have when I assembled it.everything sounds ok maybe am just over thinking it!

[Bulldog]

Thanks John my backlash is in the range

[eschaider]

Originally Posted by Bulldog

Edthanks for reply, opinion depth I can't ember shim thickness but backlash was about 8thousand.just seems like flange has some play in it it did t have when I assembled it.everything sounds ok maybe am just over thinking it!

Pinion depth is not the thickness of the shim it is the distance from the center of the carrier bearings to the face of the large bearing seat on the backside of the pinion. It is apparent that you did not set this dimension when you assembled the ring and pinion to the carrier. This needs to be done.

Once you have pinion depth correct then you want to assemble the ring gear to the carrier to minimize runout. Both the ring gear and the carrier will have some amount of runout. What you want to do is measure the runout and then clock the two during assembly to minimize the assembled run out. That will allow you to run less back lash without the ring and pinion binding up.

Rotate the pinion multiple times to be sure it has no crabs anywhere throughout a complete rotation of the ring gear. If you have a 3.08 ratio it will take 3.08 turns of the pinion. If you have a 3.55 ratio it will take 3.55 turns of the pinion. Always round up so 3.08 will become 4 turns and 3.55 will also become 4 turns.

If you have properly minimized the runout you can easily run with a 0.005" backlash. If you have very good control of the runout you can go as low as 0.003" to 0.004" but you will need an oil cooler because the tighter clearance will add heat to the operating assembly, especially on the highway. Do not go below 0.005" back lash without an oil cooler.

If this type of setup is a bridge too far, then you need to take your rear end to a shop to have the work done for you.


Ed

[Bulldog]

Thanks Ed for additional info. Its apparent i slipped up on the opinion depth, it has been many years since I attempted to set up a rear end.i will have to rethink this.