New z3 2.8

[Gareth Brass]

Hi there,
Looking for advice and probably a rough cost on repair.
I bought a z3 2.8 at the weekend.
On closer inspection I’ve noticed one possibly two of the spot welds in the boot starting to pop.
Has anyone had this repair done and if so what kind of cost are looking at?
It’s going into on Thursday for further assessment.
Any opinions greatly received.

I’ve posted a few other pics of work needed done too
Regards

Gareth

 

[Davyhoogy]

I had an issue with diff mount cracks on mine a few years ago. I took the opportunity to go b*lls deep on a full diy makeover.
Stripped the full rear end, cut out the diff mount and cracked subframe. Had my uncle weld in a new chassis section and diff mount. What we also did was made a 1mm steel plate and welded it in the boot floor over those areas where they pop to give it more strength. Plenty zinc paint to prevent rust. And been fine since. I think i covered it in my thread 'Hoogys 2.8'

 

[Davyhoogy]

I lied. I done it on a separate thread.
https://zroadster.org/threads/rear-end-maintenance-other-bits.22628/

 

[Gareth Brass]

I had an issue with diff mount cracks on mine a few years ago. I took the opportunity to go b*lls deep on a full diy makeover.
Stripped the full rear end, cut out the diff mount and cracked subframe. Had my uncle weld in a new chassis section and diff mount. What we also did was made a 1mm steel plate and welded it in the boot floor over those areas where they pop to give it more strength. Plenty zinc paint to prevent rust. And been fine since. I think i covered it in my thread 'Hoogys 2.8'

Thanks very much for the reply
Unfortunately I think repairing it myself is beyond my capabilities
It’s probably going to be an expensive garage job.
Really hacked off with myself as it’s the only thing I forgot to check!
Do you think it’s an expensive repair?

 

[Nodzed]

If they are just cracked and not pulled get them drilled out and welded back up.. Also looking at the diff bush it looks fairly knackered, I would change it ASAP as that wont help with the welds and was most likely adding to the cause if the diff was sloping around in the carrier.

 

[Gareth Brass]

If they are just cracked and not pulled get them drilled out and welded back up.. Also looking at the diff bush it looks fairly knackered, I would change it ASAP as that wont help with the welds and was most likely adding to the cause if the diff was sloping around in the carrier.

Great thanks.
That sounds like the cheaper option at the minute I’m pretty sure one has definitely popped with one possibly about to go.
I’ve ordered a new bush yesterday for the diff.
Do you think the driveshaft flex disc would add to the noise too?

 

[Davyhoogy]

The issue of cost will shoot up if the rear frame needs dropping. Any work on those areas under the car would require that. So would be alot of labour. I wouldn't fancy just welding them from the top without sorting the underside as it'll just rust again

 

[Nodzed]

Do you think the driveshaft flex disc would add to the noise too?

Yes if the diff is that bad the donut's newness has probably worn off

 

[Nodzed]

I wouldn't fancy just welding them from the top without sorting the underside as it'll just rust again

Best option short term until some refurb can be done (if its going to) and better than leaving as it is.

 

[Gareth Brass]

Best option short term until some refurb can be done (if its going to) and better than leaving as it is.

Thanks.
I’d probably like to get it done properly as I want to keep the car, but may have to settle for a short term solution.
Try to find rough estimate of cost for the full job, but can see to find costs.

 

[t-tony]

If you drill the spot welds off from the top using a proper spot weld drill bit it should just remove the top "layer" of metal leaving the bottom layer already cleaned up ready for welding. If you can drill the welds off it should be a simple job to re weld them. You do have to drill accurately in the centre of the spot weld.

These drills vary a lot in price.

https://www.ebay.co.uk/itm/10PCS-Cu...003488?hash=item56cf884be0:g:E8UAAOSwZ4pd1g6C

Tony.

 

[Shelly]

 

[Redsheep]

Is this essential at this stage?
Mine is almost identical and has been for a number of years - not getting any worse ( 2 indented with slight rust - before I cleaned).
I remember being worried about it initially and comparing it to others on one of the Scottish runs and about 4 cars had the same.

 

[Redsheep]

Just went out to check - yes almost identical

 

[Slam]

Hi and welcome from London

 

[Mint]

Hi @Gareth Brass, to the forum from me too in Staffordshire.

 

[Rha]

Hi and welcome from me in Hertfordshire.

RHA,ROY.

 

[Lee]

Welcome Gareth. I’ve just done a spot weld repair on a Zed. Drilled out the 6 spot welds to expose bare metal and plug welded them. Tidied it all up with a flappy wheel and sealed it in.