drive shaft differential help needed

[Kedzierski]

I was shifting into reverse and I heard a small knock coming from the bottom rear. I checked underneath and noticed that the input shaft on the rear diff. had around quarter inch play on it. Removed dip stick found very small quantity of metal filings. Any suggestions??? Thanx all...

 

[B.G. Smith]

If you mean the drive shaft can be turned 1/4" back and forth, that's probably normal. A little fine metal particles in the differential after several thousand miles is also not something to be too alarmed about. If on the other hand, you can move the drive shaft up and down 1/4" inch, that is serious problem. If you hear bearing noise or roar from differential along witl abnormal amount of metal, that too would be serious. bg

 

[Kedzierski]

There is no up and down play but it has a small nock when drive shaft is moved by hand. It only has 24000 miles on it.

 

[Nate]

1/4" is normal. What your seeing is the backlash with the ring and pinion and also the spider gears.

 

[Kedzierski]

what do I need to do?Should i live it alone?That noise just bugs me. I never had it there before.

 

[Nate]

The rotation of the driveshaft is normal. In fact, if there was no backlash, you'd burn up the ring and pinion set, since when it heats up, it needs that room to expand.



The clunk though, that may be a u joint going bad.

 

[Gunny]

I think Nate has this right on the money. The clunk you are hearing could very easily be a U-Joint getting ready to head south, this also could be the reason for "SOME" of the play in the shaft, maybe, maybe not, but worth checking out.



Gunny

 

[Kedzierski]

It is not my u U-joint I just replaced two of them. I went under the truck and i definitely heard it coming from the rear differential. I moved the drive shaft with my hand and i could hear the hollow knock from the differential.

 

[Nate]

Without me actually seeing it, it's hard to say.



You could always pop the cover and take a look to make sure everything it ok.



Nate

 

[Kedzierski]

I left it at the shop this morning and I should know tomorrow what is making that knock.