Z3 2.8. Diff mount has come away from chassis.

[cheeseandbeans]

So as some of you may have read I bought a 2.8 last week. In good condition internally and externally but sold as spares or repairs as it had not MOT. Took it for a drive when it arrived and it was making a loud and violent shaking noise from the rear end.

Meant to get it up to the garage this weekend but unfortunately didn't get time so just jacked it up on the drive for a quick look.

Unfortunately it looks like the rear diff mount has come away from the chassis. Obviously I'm going to get this sorted but any advice from people who may have experienced this issue themselves?

Thanks

 

[hard top]

Have you checked your boot floor spot welds?

 

[cheeseandbeans]

Have you checked your boot floor spot welds?

Just had a quick look. Well and truly shot:

https://ibb.co/frb9ev
https://ibb.co/hVKUev

 

[Grumps]

I believe there is a guy up west yorkshire way that does this repair. He's Huddersfield or Halifax I think. Sure someone will be along with the name of the place.

 

[GazHyde]

That's about as bad as I've seen, don't drive it. Find a decent automotive welder and get a quote. May well be fixable despite how bad it looks.

 

[mrscalex]

That's a bit of blow.

I would have the arch liners and sill covers off to check the structural sills before committing any more money.

In fact do an assessment of the whole car. Just in case it's a bad'un. No reason to think it is though.

 

[cheeseandbeans]

Cheers for the replies. It's booked in for Wednesday anyway to get it on the ramp so I'l have a good check around. It's such a nice car it would be a shame not to repair but it all comes down to cost I suppose.

 

[mrscalex]

Just be careful drawing conclusions about the structural sills from the outside. You can get clues but can't ultimately draw a conclusion.

 

[cheeseandbeans]

Just be careful drawing conclusions about the structural sills from the outside. You can get clues but can't ultimately draw a conclusion.

I'll take them off and have a look underneath. Presume I'm looking for cracks under there too?

 

[hard top]

I don't know what you paid for the car but I only know one bloke who makes a kit to fix this and he is in the USA, @Randy Forbes.
And it ain't cheep.
IMHO, I would break it to recoup some cash, other repairs, other then the bloke's above, never seem to work as far as I have read about.
Sorry to say....

First rule of buying a 6 pot, pull the boot carpet up.

 

[cheeseandbeans]

I don't know what you paid for the car but I only know one bloke who makes a kit to fix this and he is in the USA, @Randy Forbes.
And it ain't cheep.
IMHO, I would break it to recoup some cash, other repairs, other then the bloke's above, never seem to work as far as I have read about.
Sorry to say....

First rule of buying a 6 pot, pull the boot carpet up.

Paid £1650 for it knowing it had no MOT and it was a slight gamble. Won't lose out too much I wouldn't have thought. The panels are really straight and it has the sports seats etc.

 

[hard top]

Won't lose out too much I wouldn't have thought. The panels are really straight and it has the sports seats etc.

There you go, there is a lot of your cash back right there, I have seen sport seats go for silly money on there own.

 

[mrscalex]

I'll take them off and have a look underneath. Presume I'm looking for cracks under there too?

Not cracks. Rot.

In my view not worth starting to plough proper money into a car until you know it's solid.

Road silt enters behind the arch liners due to a poor design and it stays there - wet. It's shocking what can accumulate. Fistfuls of it.

The sill covers rot from the inside out. So if you wait for external evidence it can be too late.

Most Z3s are quite rusty under there but it cleans up. Some will be rotted though. Have a look here.

https://zroadster.org/threads/offside-sill-needed.19130

There's no connection between the diff mount and the sills. Other than if the car has been neglected. It's just general advice before you chuck money at a car not known to you.

 

[sirius-c]

I believe there is a guy up west yorkshire way that does this repair. He's Huddersfield or Halifax I think. Sure someone will be along with the name of the place.

He doesnt do them anymore, I enquired last year.
My boot welds had popped (no Diff tear) and a guy called Alan at Cracknell's Garage in Summerbridge, North Yorkshire did mine.
He did a fine job too, stitched and puddled those things

 

[Bumpa]

There are Youtube videos of the diff mounting and cross member repairs. In the one I watched the guy cut a long slot in the boot floor and welding lots of strengthening steel into the cross member, as well as putting extra metal at the sides of the boot floor as a support. Not a job for the faint hearted. The body was designed for a 4-pot 1.9 litre engine. Adding an engine with more than double the torque seems to be the problem as it mostly afflicts those with 2.8 or greater engines.

 

[lightning]

BMW do a repair piece for that. But it's only listed for the Z3 M.
A search by your dealer under Z3 won't find it. They will tell you the boot floor is "different" in the M version, but the part fits and it's under £50

 

[cheeseandbeans]

BMW do a repair piece for that. But it's only listed for the Z3 M.
A search by your dealer under Z3 won't find it. They will tell you the boot floor is "different" in the M version, but the part fits and it's under £50

That sounds very promising mate! Any links to more info on this?

 

[smiffy]

Also doesn't help that the Z3 uses a single mounting point whereas the 328i has dual mounts.

 

[lightning]

Yes two part numbers.

41118398664
Listed as "Gearbox suspension" but it's nothing to do with the gearbox, it's just a diff mount repair bracket
41117033491
Listed as "Repair part, insert, rear axle support (M Only)
This is a much bigger piece and has about 10" of the crossmember.

I fitted the smaller bracket to my 2.8. The larger piece was not necessary on mine.
This was back in 2008 and you'd have to check the parts are still available.
BMW are pretty good on parts though.

 

[Grumps]

Speak to Sopers at Lincoln.