Vibration woes 05 Monaro

[aboomshanker]

So.....a few months ago my mechanic recommended a new prop shaft centre bearing for my 05 Ro, which was duly fitted. Since then there's been a fairly significant vibration from the drivetrain. It seems to be speed related not revs. Had prop shaft rebalanced and new UJ fitted. Thought "great, sorted now" But it's actually made it much worse!

Today my mechanic put it on the ramp. Removed drive shafts, ran car and still the vibration. Then disconnected prop from gearbox and vibration gone!
Prop shaft back on, vibration returns. Hoping it's not the diff as it's an upgraded one from Monkfish which they installed

Does any kind soul have a prop kicking around I could try swapping out to see if that makes any difference as I don't really wanna buy one as it's about £1000 and might not fix the problem

Oh, we also rotated prop every which way to no avail and donuts look good. Might anyone have any suggestions please? At my wits end!

Any help much appreciated as usual

Thank all

Pete

[SturdyHSV]

When replacing the centre bearing, the prop needs to be marked and then put back together exactly the same as it was, else it won't be balanced.

I'd guess that it wasn't put together exactly the same as it was, it wouldn't be hard to get it a tooth out on the spline to be honest.

For reference I don't mean put back the same in the car, I mean as in the front and rear halves of the prop must go back together in exactly the same orientation relative to each other as they were.

[aboomshanker]

Hey, that was quick lol. thanks for replying. Yeh it was put back in the same place, my mechanic marked it up. And then I'm assuming the guys who rebalanced it did the same. They were a company in Sheffield used by AAS

[Lincsls1]

So from your post I'm making the assumption that before you had a new centre bearing fitted, you weren't experiencing any vibrations? That should really eliminate the gearbox, diff and even driveshafts.
Really does seem like the prop hasn't been done properly. Mistakes happen at the end of the day. I'd be tempted to try and get it rechecked at this place in Sheffield or somewhere different.
Years ago I had a centre bearing changed on my 300zx, upon getting on the motorway the vibrations were horendous, I went straight back to the garage and they split it, spun it 180 degrees and the problem was solved.

[Lincsls1]

There is always this to try, offer him £40...
https://www.ebay.co.uk/itm/166305825780?hash=item2...qYAAOSwScJk7yNO&amdata=enc%3AAQAIAAAA4F6EkEtsucGyofSJjKaG76bug%2F31acNSiTrU2SPe0sV253%2BskqI1L087KAfkdTs%2B2jH%2F2QSmt4Gpr8PW%2FUpWzsAx08gp0wdRnEEsgN%2BcdFlYO%2FPwdiaoAYqtRgoXsZvE10Effl5jhn3GIG3Sfv%2BRSCWPYXiunC66JhqHRVqZogSxmfTRCwcaLI4j6nasqKzoCKcMZe8%2FPF7ECueQkKWHmw8BkhLUvvWYm6ORpEAceAJk3tpO%2FyQzzswwpFDQ1ina1TBepTStVi3ROXnf73MYP6if69AiTPgif1bfzxg2hQUp%7Ctkp%3ABFBMkNDfzMli

Despite the strange listing, it came from a 6.0VXR. This will fit small boot 5.7 too, but there are differences with the big boot models.

[aboomshanker]

Hey, thanks for getting in touch
Yes there was no vibration before new centre bearing was fitted. Mechanic did say maybe it's not been done properly or damaged in transit

My Ro is a 2005 small boot so I'm gonna get that prop you sent the link for. Deffo worth trying for that price. Thanks very much again!

Had my Ro for 15 years and no intention of getting rid, still gives me a buzz after all this time

Must say yours looks nice and you've done a lot to it.

[Lincsls1]

Thank you kind sir! It's been a labour of love, a rolling rejuveniation project rather than restoration if you like. Not finished yet!
Keep us posted with how you get on.

[aboomshanker]

I certainly will. Offered the £40 so will see, I'll have it anyway for £50 TBH

Keep up the good work