Knocking Under Heavy Acceleration

[TouringMatt]

Had to do a quick exit onto a roundabout yesterday, wheels started spinning then a massive judder/thumping came from the rear/left of the car

Now it happens when ever i boot it hard enough in first to get the wheels slipping, other than that it drives fine.

Had new rear bushes 12 months ago, checked under the back and all seems fine, can move the diff bush slightly using a 2 foot bar but it does not look worn or split

Any thoughts?

[clubfx2]

rear mont bushes, sounds like.

[1an]

beam bushes, are could be a nice bit of axle tramp.

[TouringMatt]

I changed the rear beam bushes just over 12 months ago though, is it usual for them to go that quickly??

[fuzzy]

id put my money on the prop centre bearing.ive destroyed a few with heavy acceleration.

[1an]

did you do the trailing arm bushes aswell? could also be top mount or as fuzzy said prop centre bearing

[TouringMatt]

Dont remember changing the trailing arm bushes, changed the top mounts for E46 ones.

Is it possible to check the prop bearing without removing all the gubbins first?

Could it be a knackered shock also?

Cheers

[fuzzy]

ive never had to do the trailing arm bushes yet so cant comment on that. i think the top mounts would knock at all times when driving over bumps and not just when accelerating. when my prop centre bearing went it was also when i accelerated hard .it was rattling about in the transmission tunnel from then on and would only knock on acceleration. it was banging in the centre of the car just behind the front seats though and not as you say rear left but worth checking.ive had a couple of bearings tear around the rubber but also ive had the metal ring around the rubber on the bearing snap away from the carrier at the welds .

[fuzzy]

just crawl under the car ,have a look up and wiggle the prop at the bearing . it should be pretty obvious if it is that.

[TouringMatt]

I think your suspicions were right Dr Fuzzy, tested it again and put my hand on the exhaust tunnel behind the passenger seat. I could feel the knocking there which also ties in with the rattling bag of spanners noise i heard the the first time it happened - the rear ash tray is full of coins!

Cheers!
Matt

[oze30]

I'd gpo with fuzzy and say the prop bearing. Mine did this but I thought it was the exhaust hitting. Changed the bearing when I did the M30 and no probs.

My front ashtray has all the coins!! The rear has numerous nuts and bolts that I keep finding in the touring!! but I had the same experience!!

[keego1ie]

i have to agree with the prop idea had ther same knocking myself last year it looked ok took it off it was in shite changed it problem solved

[TouringMatt]

I need to change the prop coupler anyway so at least i'll be working in the same area!

Cheers for the responses guys

Matt

[aceraf]

This bugs seems to be spreading, i think my tourings developed the same issue.

(325i sports auto).

I've noticed that on level ground or uphill it makes a knocking when reaching high revs, and the noise seems to come from behind the front seats around the middle of the car (doesn't seem to happen that much on downhill).

The car drives fine if i drive normally, but when you give it some, then you get the knocking sound!

Is this doing major damage, or is it okay to drive the car normally till i've rectified the problem?

Also can anyone suggest a rough price to get this fixed?

[aceraf]

To answer my own question about the price and anyone else who may be bit by this bug:-

ECP:-
LEMFORDER 652110045 PROPSHAFT CENTRE BEARING BMW E30/E32/E34 £20.54

Can anyone comment on how easy/hard it will be to do this job, and whether it's worth doing myself or giving it in to a garage.

[fuzzy]

easy easy easy do it yourself in an hour.its a nightmare job for me with my custom prop requiring driveshaft/diff removal but standard stuff is easy to remove.

[Chris-W]

Exhaust down, heat shield off, undo prop at rear, remove rear half of prop, unbolt bearing bracket, drift old bearing off / new one on, re-attach new bearing bracket, rear half of prop, pre-load bearing, re-attach shield and exhaust.

Not too hard.

[aceraf]

Thanks

[Dan318-is]

If you have been fiddling with the diff it can also be the four m12*1.5 bolts that hold the diff in through the subframe. They need to be tight / not missing.

[fuzzy]

I think your suspicions were right Dr Fuzzy,

woo hoo. after 3 years ive finally got something right.
id like to thank my mum and dad for making all this possible ,my teachers who taught me through school, god who has led the way ,my pet cats fuzzy and wuzzy and everyone who has helped me and believed in me over the years

[Stu_D]

I had a similar problem on my first touring went through all the suggestions up here, turned out to be some lovely guy had cut one of the rear springs, obviously figured it was a bad idea and just left it, nice or what!!

[TouringMatt]

Just waiting for a dry weekend now to fit it - the forecast looks bad!!

[TouringMatt]

after 3 years ive finally got something right

Alas, you were wrong my friend!

Turns out the prop coupler had just disintegrated, t'was a real mess, probably not helped by the muppet that fitted it with the arrows facing the wrong way

Changed the center prop support while i was there - the bearing was slightly noisy but for what im guessing was an original item on the car it was in bloody good nick!

Even managed to adjust my handbrake properly and rob some parts off my spare gearbox to repair the sloppy gear linkage bushes - all in the rain too

Cheers!
Matt

[fuzzy]

after 3 years ive finally got something right

Alas, you were wrong my friend!!
Matt

oh b0ll0cks you tease me with hints at glory then snatch it away from right under my nose at the last minute.thats just cruel.

[Nelly]

Fuzzy Wuzzy was a woman?? - classic film