Broken differential?
 

My 915 transmission (no LSD) started making a clunking noise today. I've checked the short shafts and don't think there's an issue there....

However, with the rear jacked up, I tried turning one rear wheel and noticed the other side not turning in the opposite direction. Shouldn't it?

Can you help me understand what's probably wrong? Can you identify what parts based on my brief description?

thanks,

Usually that does happen when both wheels are hanging clear, but if in neutral then not always if there is a bit of brake bind. If its in gear and you prevent one wheel from turning and you can turn the other you have issues.

Okay - I'll jack one side up (in gear) tomorrow AM and see if I can turn a wheel. If I can, what kind of issues internally?

Don't think I had sufficient brake bind to restrict rotation on the initial test I described above.


thanks,

CV joints clunk. pop. snap...

That's my thinking on it.

thank you John & Matt.... that was my first guess and that's what I went for. But when I lifted the rear end and the opposite wheel didn't counter rotate, I thought it might be internal.

I can now try and do some simple turns and see if it occurs in one direction vs. the other.

I also lifted one side at a time and while in gear, couldn't get either wheel to rotate, so I guess I passed whatever test that was for...

Can you guess why my turning one wheel and the other not counter rotating might be due to? Or, that was your point - the CV isn't linking to the trans?

thanks,

Make sure the axles are not spinning in the CVs (due to bad splines at the end of the shaft).

thank you.

aside: one of the first problems I ever had with a car was due to a bad spline. Year - 1964 on a 1957 Austin Healey... right rear wire wheel.... "you mean you need to put grease on that?"

thanks

… axles not spinning in the CVs - at least for turning wheels by hand.

So, I'm hoping someone will help answer the question - with the rear end jacked up, and assuming the CV joints are okay, why doesn't the opposite wheel counter-rotate when turning one side? (this isn't a limited slip)

Anybody experienced this - and what caused it?

thanks again,