what trans did you install. is it a T5? I have read a ton of threads with this same issue on a T5 conversion. infact i am having the same issue.

I have found after going through everything including new rear end, new drive shaft balanced to 10k rpms and changing my pinion angle that the T5 is slightly rubbing on the tunnel support.

 

Yeah that could do it..did you correct that issue Billy? Did it solve that vibration issue you were having?

 

Driveshaft guy called me and said that the U joints where causing the vibration. I guess the greasable U joints go out pretty quick? Installing better U joints and re-balance driveshaft $200. I have a feeling that when I re-install the DS its still going to vibrate

 

ya, put it back in and report back. As monsterbilly said, T5s are notorious for hittijng trans-tunnels. I had that in mine as well when installed, but that was most worse at around 50mph. was the first thing I changed, then I did the puinion angles with angle finder. now it only vibrates at 75+mph and I never pushed it passed 80 with that. simply scared to drive a vi9brating car at 80mph. in my case I'm betting it's the driveshaft as it's the only 'used' part. all else was brand new. bought it 2nd hand, so I couldn't tell if it ever was bad.
But ya, a buddy of mine had a problem with his up in Dublin about 2 years ago. he sent the driveshaft away to UK and they told him as well it was the u-joints. They replaced them and he never had a problem since. So there's hope for you :-)
I am in contact with the same crowd, they're going to make me one measured to size. so when I change the wheels on the weekend I'll measure the old shaft up and order.

 

order an aluminum...they are a whole lot lighter. i wish i had

 

+1 on that

 

So I got the DS back tonight and installed it put nice sealed ujoints. It is a lot better but there is still vibration there. It goes higher into the RPMs about 3k which is probably 80 or so before it starts to vibrate. Not window shattering anymore. Should I try playing with the pinion angle again now that the driveshaft is better? I have not checked the axles yet. I will also probably get the tires rebalanced as it looks like a couple weights came off one of the wheels.

Thanks guys
Dan

 

I bet its just tires now....I spent hrs messing with pinion angle...I was able to make things worse but that's only because it wasn't pinion angle in the first place.

I would go back and set pinion angle to +2 -2 OR if you can get a +1 -1 even better BUT there should be absolutely no issue with +2 -2 since you already have the wedges for +2 -2 set it and forget it. Its not pinion angle

-Gun

 

Its actually a 4 link set up so no wedges

 

not real familiar with how that works but if you can dial in any number split the difference and shoot for a +- 1.5

That enough to keep the bearings in the U joints spinning and keep operating angle to a minimum.

-Gun