Hey guys.. i've had a problem for a while now.. a shuttering when downshifting and when I reverse and take off... I originally thought it was the diff bushings... so I replaced them and helped but didn't elimate it completely.. so I jacked the rear end up... and reversed while the rear end was up and noticed the diff was very lose and shaking causing the sound and vibration. Is it possible to tighten it up somehow? I did replace the bushings myself, is it possible that I didn't tighten them up enough?

Dennis,

 

Well...if you don't trust yourself enough to say that you did torque the nuts and bolts down properly, then that would be the first thing to check in my opinion.

 

The only bolts I undone were the bolts that go through the diff bushings and the nuts to get the diff mount off... do they play a big part in getting the diff stable? I tighten them as much as I could, but the sound and vibrations did occur as soon as I bought the car... Are their are nuts I can tighten? Or do I need to do something totally different?

 

What part of the diff is free to move? The whole diff assembly?

Look for play in the diff flange. If you have worn bearings in the diff assembly you can get shuddering from the driveshaft.

Dave

 

As you look at the rear end... whatever you can see of the diff from that view of shaking quite alot... it seems like its shaking towards the left side (facing the bonnet direction)... I think... any ideas??

 

Bump!

 

Is your shifter moving?

In any case look at your powerplant frame too.

Dave

 

i'm having the same problem, it didnt happen until i replaced my diff, so i'm sure it has something to do with the bolts holding it in place, buying a diff brace wouldn't hurt either.

 

At this point, just slappping a diff brace on there would be a band aid fix. find the source of the movement first, then decide if you want to add a diff brace to the mix.

 

Ok... tighten everything up... it didn't seem to move while the car was up on stands, so i'll put it back down and see... but I think I can still hear the noise... I just can't hear it as much due to no weight... I think the sounds coming from the the joining of the crankshaft and diff but then again, it could be from anywhere...

 

Prop shaft installed slightly off centre?

I've never looked at the FD prop shaft but with some cars if you install it off centre it wobbles like hell.

 

I re-tighten the bolts...went for a drive... at start, nothing changed... **** shudder.. after driving it a little... it all went away... I was able to downshift without any noises! But by the end of the drive, it back to normal... i'm not very strong, so if I get the bolts very tight, could it stay? I want to loctite... good idea?

 

get a torque wrench and use some lictite. check everything. including your powerplant frame.

 

That's a good idea. It only takes 10min to unbolt it and rotate it 90° and bolt it back in again.

Dave

 

Had a very good look today at everything... Diff seems to be fine... not moving anymore.. PPF is fine... checked the crankshaft, that seems to be fine... after examining more... it seems like it coming from the rear suspension? Pillow *****? I took off my rear wheels, I was messing around the my brake rotor, pushing it up and down and noticed the noise... while it was up on stands... I reversed it... than quickly applied the brake and you can hear the shudder as rear stops...?? Could pillow ***** cause this?