Crimson Fox

We got the aluminum flywheel and the SPEC stage 1 clutch in and all went well. They are broken in and it grabs nicely.
Now we installed the 4.10 gears. Since then there is a strange vibration in the driveline. We did an index on the drive line and after that the vibration went away shortly, but has since returned.
I am running out of ideas as to the cause. We double checked the gears and they are adjusted correctly. Any ideas?
We are talking about a 99 Cobra

mysticsvtcobra96

sounds to me either the gears wasnt installed right or you have a defective driveshaft thats not balanced oh and if the car sat for a while then maybe you have a flat spot on your tires?...just some thoughts

Crimson Fox

If it is a defective drive shaft, could that be corrected by taking it to a machine shop and having it balanced?
-Nicholas

mysticsvtcobra96

[sm=exactly.gif]

Boltt

Im gunna say mistorqued bolts.... Sounds like a bolt vibration to me. Is it constant, or only under certain circumstances? Like accelerating, decelerating, turning, etc.

stangc83

i heard that buying a new aluminum drive shaft fixes that problem. Is this true?? did you do everything yourself or not?? on my last car it didn't really shake but the throw out bearing rattled and it stopped rattling when i pressed in the clutch. try that.

Boltt

That would imply a bad throwout bearing and would have nothing to do with a vibration lol. Throwout bearings aren't under a load when the clutch is depressed, so when a throwout bearing goes bad it will have too much slop between the two moving parts and cause it to squeek or rattle while spinning freely.

Crimson Fox

The work was done by a professional.
It only happens at speeds of 75+. It gets really bad around 110.
Bolt vibration where?
The throwout bearing is brand new, we replaced it with the new clutch and flywheel install.
So I guess the question now is:
Do we balance the existing driveshaft, or do we get a new aluminum shaft?

-Nicholas

Boltt

Bolt vibration wherever there are bolts? If it happens at a certain speed, you probably have a bolt loose at any of the points connecting the driveshaft, at either end. Check all the bolts, make sure they're tight and torqued.

GodAmGT00

I'm going to also mention that driveshafts should go back on the car the same way it came off.. It sounds more or less like a balance issue, which could also be the result of improperly torqued Pinion flange bolts...

When was the last time your U-Joints were done?? What shape is your tranny mount in??



JT