So I swapped the TII drivetrain into my car the other day. The diff whines at all speeds and has a very slight clunk/thud when I push the gas or engage the clutch hard. There is also a LOT of vibration when accelerating past 6k RPM.

The axles have a lot of up and down play from the diff side. Not the joints but the flange(?) that the axles bolt on to. Both wheels also have up and down play. One of the axleshaft nuts is crossthreaded and barely holds any torque.

I changed the diff fluid to Castrol GTX Hipoy C as suggested by Pep Boys. It didn't have a viscosity rating, wrong fluid? I'm changing it tomorrow anyway...

The diff is from Japan2LA and has nice poly mounts installed so that maybe be all the vibration is but I'm not sure. Other than this it drives fine..what could the problem be?

 

It might be those poly mounts, but maybe you might want to look into rebuilding it soon if it whines all the time. I'm not too sure. You never said what kind of TII drivetrain it was. It is from a s4 or s5? (Clutch type lsd or vlsd)

Go with 75-90w Mobile1 full synthetic, or red line, or royal purple, anything full synthetic that is heavy weight will do fine. Why cheap on on diff fluid when you only replace it once in awhile.

 

Get rid of all the play. That is the problem.

 

The stub shafts have up/down play?

 

So I went and checked my old diff which worked great and the axles have the same amount of play. Checked the diff fluid bottle and it actually does have a viscosity rating of 80W90 so its good. The whine kind of stopped somehow...it only does it sometimes. And the vibration I guess isn't bad and I can live with it. The up and down play of the wheels was just me compressing the shock since the springs put no tension on the wheels at full droop (Ground control coilover sleeves).

Its an S5 diff btw. I still get that clunk though when I engage the clutch, its definitely the diff hitting the subframe...Are the washers for the axle nut a different thickness on TIIs? The halfshalfs just don't seem to be completely inside the knuckle.

 

it IS mount related
get a pinion snubber, it is not gonna fix the problem entirely
but it'll help

 

what kind of poly mounts do you have?


cause i have mmr mounts and you could hear the diff in the car

 

I don't understand how it could be mount related when the two mounts were new and the front mount was in good shape (better than my old one). I don't know what brand the poly mounts are, I got the diff from Japan2LA with them already installed. They're kinda brownish and they're clear.

I think the problem is one of the halfshaft nuts not having any torque on it (crossthreaded)...going to replace that tomorrow and see what that does.

 

I have a very similar prob.

I have ALL poly mounts all the way around. But i still get play in the drivetrain. ANd my car likes to bounce on low speeds AS IF one of my rear tires(which are brand new) had a small titi on it. I could have play on the axles that could cause this slight bounce right?


It must be those subrame mmounts i never replaced. The big ones closer to the middle of the car.

 

Its the ******* front diff mount!!!

I jacked up the wheels today and had a friend engage the clutch for me and sure enough the front diff mount was flexing enough to allow the diff to hit the subframe and the chassis. What a BITCH. Can I use the mount from my NA diff?

 

yeah they are the same as far as I know.

Joe

 

yeah well thanks to sub9lulu it looks like I'll be installing a pinion snubber.

 

get a mazda comp front mount... the stockers are known to be weak.

goodluck! hope you get it sorted out.