I admit to roughing up the car a little but I can't imagine having done anything to damage the differential.

My car has developed a "roughness" in the rear end and I am thinking it may be the diff.

At my latest time-trial(Solo 1) I felt a vibration coming from the rear in a low speed turn with lots of gas on. At the time I thought it may of been a tire(Hoosiers) but an inspection between trials showed nothing wrong and the vibration came back the next time out.

Now I feel a roughness from the rear during straight line accleration in the street.

Are the two related ? Could it be the diff ? Has anyone else encountered these sympthoms ?

Thanks,

Pierre

 

The vibration in low speed turns is a feature of the Torsen differential - I have experienced this since new and my Stook is now 21 months old.

Don't know about the straight line acceleration issues though.

 

If your tires are out of balance or have been dragged you could develop the behavior you are describing. The tire structure itself may be damaged. Does this only happen at low speed? Does the shaking still occur or get worse at 100+ mph(I don't know the kph).

 

How do you know if it doesn't cause by your differential fluid? Has you replaced your diff. fluid? How many miles do you have on your STooK? Just a thought...

 

My car also has a bit of vibration under acceleration. It has had it for about a year now. In the past year (since it started to have the vibration), I have changed the clutch, flywheel, pressure plate, differential, and tires. None of those things made it go away. I have checked the runout on my propshaft and it's not bent. So either something in my transmission is bent (which I doubt because it would probably grind a lot if something was) or the pinion gear in my rear end is slightly bent. I eye-balled all the parts in my rear end to see if anything was bend when I re-built the rear end and nothing appeared to be, but I really should have checked the runout.

Another possibility is the axles. I believe I did check the runout on them a few months back and they were fine. But - the vibration did start around roughly the time I lowered the car. So (this is a stretch) I guess maybe the car doesn't like the angle from the diff housing to the wheels now and the cv joints are causing the vibration. That's especially far fetched because I only lowered it 1.1" (used HKS springs), but I still have to consider it a possibility since there was a strange correlation between when I lowered the car and when I noticed the vibration. Pierre, is your car lowered also???

In my car, the vibration is present when I accellerate, at any speed. It doesn't get worse with higher speeds, maybe just a little higher frequency. I don't think it's an engine issue because it seems to correlate more to wheel speed than engine speed, but I could be wrong. It hasn't really gotten any worse in the past year. I don't worry too much about it except that I hope it's not related to something being broken. My friend notices it more than I do and he considers it a pretty significant vibration But, like I said - I don't think it's all that bad - just bothers me that I can't figure out what's causing it.

 

[QUOTE]Originally posted by Pierre'stook
[B]I admit to roughing up the car a little but I can't imagine having done anything to damage the differential.

My car has developed a "roughness" in the rear end and I am thinking it may be the diff.

At my latest time-trial(Solo 1) I felt a vibration coming from the rear in a low speed turn with lots of gas on. At the time I thought it may of been a tire(Hoosiers) but an inspection between trials showed nothing wrong and the vibration came back the next time out.

Now I feel a roughness from the rear during straight line accleration in the street.

Are the two related ? Could it be the diff ? Has anyone else encountered these sympthoms ?

 

Mine is doing a clunk/click/clank sound when I start from a dead stop of come to a complete stop. It also does it when I'm in first and I blip the thottle or let off. I have mine in the shop right now and they are looking at it. They get the same problem but haven't figured out what it is yet. They suspect a loose bolt in the rear suspension so they are going to retorque them and see if that helps.

 

This would be a rolling clinking sound that would only be heard at lowest speeds almost before a dead stop. At higher speeds the clinking becomes a higher frequency "whirring" which is much harder to hear.

 

I had vibration under acceleration too this week. I took my car in to get an alignment and now it is gone. They said that i had too much Toe-in. I would tell you all with this problem to get an alignment. I thought it was my new diff. that i have had for 3 days now. But it was not. To my relief.

 

I have already had mine aligned and it did not fix the problem.

My list of things I've tried to get rid of the vibration currently stands at:

-Alignment
-New tires
-Clutch
-Flywheel
-Differential
-Checked runout on propshaft and axles
-Sacred dance around car while praying to gods to make it stop