1 Peice Tailshaft Probs After Rb25 Box Conversion.

[dangerous_daveo]

Ok, so got the rb25 gearbox in. Car moves, so all is well. Get it up to speed it starts to vibrate. So back the car goes to check if the shaft is actually ballanced correctly and is straight, my mechanic went down with the car, so apparently thats fine. (apparently)

So the drivetrain people said the uni's have too much stress on them, the box needs to be raised. So, that was done, was rasied up 10mm, did bugger all to nothing (vibration moved from say 80kmh-90kmh, so an improvement).

Now my mechanic is saying it could be my diff angle. As I have those funky pineapple things, and the car being a cefiro, its most probably set up for drift.

So, now my question. Is chaning the diff angle going to help, or is the drivetrain mob trying to fob us off. Others oppinions so far is the shaft has a slight bow or bend in it. Therefore meaning even if balanced, it will still wobble. That said Id like to change the diff angle regardless.

Also what damage could I be doing by continuing to drive it?

BTW, as I forgot. Car is an 1988 cefiro, rb20det, with now an rb25det manual gearbox. One peice tailshaft like the topic says.

So any thoughts please post away.

[boostn32]

Dave its the tail shaft hands down. either its not ballenced properly or its bent. it will eventually flog out the unis and the bearings in the front of the diff and rear of the gear box

Edited August 16, 2005 by boostn32

[predator]

sounds like it hasn't been balanced correctly..

one piece tailshafts can be very difficult to get right..

[r33_racer]

Yep tailshaft...maybe try and source another one to see if its any different. Or take it to another balancing mob and see what they say about it...get another opinion. The blokes your going to now might be on drugs and off with the fairies.

[blind_elk]

Are the uni joints aligned properly - each end needs to have the correct angular relationship to the one at the other end, otherwise they "fight" each other.

[dangerous_daveo]

Well to give a quick update. We rasied the box up another 5mm today, did bugger all. However we also had the rear end up on stands, and took it up to about 100-110kmh, the tailshaft, diff, gear stick etc hardly moved, yet the left rear wheel, and not so much the right rear wheel did start to flop about a bit.

Now before you say wheel blanance, I have had two sets of wheels on the rear now, both didnt have a problem before, both now do, at the same speed. However having a 2 way diff, and no load could be playing with that a bit.

Anyway, its going on a dyno tomorrow to try and narrow it down more. We have decided to narrow it down to diff bearing, or the tailshaft.

But if anyone else has any ideas, post them up, we are all ears.

[r312dr]

if i understood what ur saying properly

why are u saying its the diff bearing if its only started since the new gearbox was put in

if so it has to be the output bearing in the gearbox or the tail shaft is not balanced properly

and dont worry about what it is doing on car stands u dont drive it there

[dangerous_daveo]

Sorry forgot to update this.

We put the car on the dyno, tailshaft just wobbled like nothing else. So we went back to the driveshaft place. They said AND I QUOTE!!! "yeahhh it was the uni's we have had a few probs with that sort recently, so we put another type and brand on, should be ok now, bye"

I was not overly impressed, if it was for the sake of $50, I would have paid the bloody money in the first place. But its fine now 180kmh still smooth.