Gear change thud

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Jones67
Joined: Fri 10 Aug, 2012 12:00
Posts: 22

  Z3 roadster 3.0i

Gear change thud

Post by Jones67 » Mon 20 Apr, 2015 17:14

Hi all, I have a thud when my auto changes from 2nd to 3rd is doesn't seem to be there between 1st and 2nd and the others aren't so bad either. I change the gearbox filter last year and the fluid but the problem is still there:head:

Any ideas what it could be I have read on other sites that it could be an number of things like the propshaft coupling or rear bush wear??

Brian4
Joined: Mon 19 Dec, 2011 19:02
Posts: 539

  Z3 roadster 3.0i
Location: Hinckley

Re: Gear change thud

Post by Brian4 » Mon 20 Apr, 2015 19:03

Can you tell where the thud is coming from rear or centre of the car.
Probably is the diff mounting bush from the diff to the subframe.

The flexible coupling is propshaft to rear of gearbox so would come from centre of the car.

Have a look for any cracks in the rubber or movement in both of these .
Brian
3.0I Topaz Blue


2000 E36/7 Z3 3.0i
2016 F31 335d
2015 F21 118i

Jones67
Joined: Fri 10 Aug, 2012 12:00
Posts: 22

  Z3 roadster 3.0i

Re: Gear change thud

Post by Jones67 » Mon 20 Apr, 2015 19:32

Thanks for the reply, it seems to be more at the back it as if the drive is suddenly taken up. if it is the is the diff mounting bush from the diff to the subframe is something that I could do myself or would the car need to be on a ramp??

Brian4
Joined: Mon 19 Dec, 2011 19:02
Posts: 539

  Z3 roadster 3.0i
Location: Hinckley

Re: Gear change thud

Post by Brian4 » Mon 20 Apr, 2015 20:06

I think it needs to be on a ramp as the diff has to come out.
The bush is in the diff but the bracket the diff is bolted to is on the underside of the car, ( I said to the subframe before but meant the body ) and this goes both sides of the diff bush so it can't be accessed in place.
Brian
3.0I Topaz Blue


2000 E36/7 Z3 3.0i
2016 F31 335d
2015 F21 118i

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pingu
Joined: Fri 30 Apr, 2004 17:01
Posts: 3363

  M roadster S50

Re: Gear change thud

Post by pingu » Mon 20 Apr, 2015 21:23

Brian4 wrote:I think it needs to be on a ramp as the diff has to come out.
The bush is in the diff but the bracket the diff is bolted to is on the underside of the car, ( I said to the subframe before but meant the body ) and this goes both sides of the diff bush so it can't be accessed in place.
The diff can stay in the car. There is a proper tool to do the job, but I would remove the diff cover an use a modified exhaust clamp.

Get the car in the air and support it on the rear suspension, so the wheels are in the normal running position relative to the wheel arches (but free to rotate). Get somebody to "drive" the car and listen / watch for the clunk.

Run the car like this...

Pingu

Jones67
Joined: Fri 10 Aug, 2012 12:00
Posts: 22

  Z3 roadster 3.0i

Re: Gear change thud

Post by Jones67 » Tue 18 Sep, 2018 14:11

So time for an update on this issue and it's been a while since posting on the forum. The Z has been off the road since late 2016 due to my wife being ill thankfully all is ok with her now. So this year I decided to get the car back on the road.

The car had been sitting on my drive way and then in my garage which was damp so the underneath has corroded a little over the time the car was however started and left to run on occasions. We moved house last year and the car now has nice modern garage to reside in and be attended to. I got her started up cleaned her off and checked her over, fresh oil and filter and took her for the MOT, it failed :(

But only on one brake pipe that was corroded :) so new MOT, the car was running but I still had this problem with the shifting. I took it to Bryn Motors in Swansea where Gary was very helpful he checked it over and told me the problem was within the gearbox, and that he didn't really work on the automatic boxes. He put me in touch with Mike Tucker autos an local gearbox specialist, Mike had the car and confirmed then was a problem in the box.

So the the outcome is that the gearbox was totally stripped and it looks like that sometime in the past someone had has a go at the gearbox because the springs in the vale bodies were the wrong length. With the gearbox it bits I called in to see mike he showed me the parts and told me what he was going to do.

The gearbox has now been fully rebuilt with a new valve body new solenoids clutches, well basically everything was replaced so part from the case it's all new.

The car now drives and shifts as it should come the winter it will be in the garage for a underside clean up ready for next years glorious summer.

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