Tailshaft issues

[someguy360]

Hi Guys.

around a week ago I had the uni joints & center bearing changed on my VS due to the bearing being on its way out and the uni's had a fair bit of play in them.

There was a little bit of vibration from the bearing before the change but not really noticeable.


Since the mechanic swapped the uni's and bearing over the whole car violently shakes from the rear end/tail shaft on light throttle, when I am up to speed its not as bad but its the worst during take off......also seems to get a bit better once the car has warmed up aswel

This has only happened since I left the mechanic after picking up the car so I took it back and he put it up on the hoist and said the shaft appeared to be aligned properly and there was nothing noticeable and to give it 100km or so for it to run in and settle .

I have now done 500km and its slightly better but not by much?

Anyone know whats causing this, I will be taking it back to the mechanic again but don't want to go in without any knowledge on what could be causing the problem


The only thing i can think of is he didn't mark the tailshaft when he took it apart and it didn't go back the right way

Thanks

[RX25SE]

Take it back.

I would say the front and rear shafts are out of 'phase', meaning he didn't mark it.

[Jxw]

yeah sounds like a phasing issue, i've never had to "wait for it to settle in" on any tail shaft i have ever done.

[strgas]

did the spacers get put back correctly on the centre bearing ? was the front and rear shafts marked before being removed , could be the B angle and the phasing of the shafts

[ephect]

Another for phasing, if he changes them and it doesn't help, u'll be up for a balance ~$100

[RX25SE]

Another thing may be the new uni's weren't centred when they were installed. (giving the yoke a sharp crack with a hammer)

[monkeys437]

Id be guessing phasing too. Get him to have it inspected by a driveshaft specialist if he cant fix it. The advice of giving it a while to "settle down" is rubbish. Tailshafts don't rebalance themselves and if its vibrating as bad as you say you can cause damage to the rest of the driveline by continuing to drive it

[Brett_jjj]

Ive had similar stuff happen. I had bad vibrations coming from the rear of the car after Id had tailshaft disconnected from the diff. I fixed it by removing the tailshaft from the diff again, rotating the tailshaft 180 degrees, and then reconnecting it again. You wouldnt think that this could upset the balance of the tailshaft that much, but it does, it makes it vibrate pretty bad actually, after Id rotated it, it ran heaps smooth again and was back to normal..

[ephect]

From memory the yolk on each end of the tail shaft should be 90deg from each other

[someguy360]

Well he said he is certain it was marked and put back the same way

Ive had similar stuff happen. I had bad vibrations coming from the rear of the car after Id had tailshaft disconnected from the diff. I fixed it by removing the tailshaft from the diff again, rotating the tailshaft 180 degrees, and then reconnecting it again. You wouldnt think that this could upset the balance of the tailshaft that much, but it does, it makes it vibrate pretty bad actually, after Id rotated it, it ran heaps smooth again and was back to normal..

Thanks, might give it a try on the weekend