Randy Forbes Rear Diff Strengthening Kit

UK forum for general and technical discussion about the Z3 roadster
Post Reply
User avatar
Rocketman
Joined: Sat 24 Jun, 2006 16:46
Posts: 61

  M roadster S50
Location: St Neots

Randy Forbes Rear Diff Strengthening Kit

Post by Rocketman »

Would anybody be interested in purchasing an unused Randy Forbes Rear Diff Mount Strengthening Kit?

I purchased and imported the kit from the USA many years ago and for various reasons it was never fitted to my car. My car has recently been in for a 'mid-life refurb' and I decided to go with a more traditional / OEM fix to the 'popped spot weld' problem.

The kit, as such, is brand new and unused. I'm sure if you are looking into this problem you will know the kit already.

It would require an experienced welder to install.

I would be looking for £ 300.00 (plus the cost of Postage and Packing) but obviously if you live in my area (St Neots, Cambs area) pick up would be an option.

Rocketman
petecossie
Joined: Wed 11 Apr, 2007 13:13
Posts: 157

  M coupe S50
Location: Billingham

Re: Randy Forbes Rear Diff Strengthening Kit

Post by petecossie »

It might help if you put a couple of pictures up to show what parts the strengthen kit contains so people know what they are buying. Is it just the mild steel parts which are welded to the existing weak points in the diff area? Randy also does a double eared diff cover, I presume this isn't part of the kit you are selling?
GLWTS
Pete C

2000 Z3M Coupe - Cosmos Black Metallic/Black Interior.

Previous BMWs
2003 E46 M3 6 speed manual - Carbon Black/Black Interior.
2000 Z3M Coupe - Cosmos Black/Black Interior
1986 M635
1985 E28 M5
1983 E28 528i Alpina
Juvvajuvva
Joined: Sun 06 Nov, 2016 16:52
Posts: 86

  Z3 roadster 2.8

Re: Randy Forbes Rear Diff Strengthening Kit

Post by Juvvajuvva »

PM’d
Yelton
Joined: Sun 27 Mar, 2022 07:48
Posts: 3

  Z3 roadster 3.0i

Re: Randy Forbes Rear Diff Strengthening Kit

Post by Yelton »

I was really interested to hear about the "more traditional / OEM fix to the 'popped spot weld' problem" - I have a Z3 3.0i which looks to have 'popped' one spot weld and am keen to understand what this OEM fix is. Please tell
Yelton
Joined: Sun 27 Mar, 2022 07:48
Posts: 3

  Z3 roadster 3.0i

Re: Randy Forbes Rear Diff Strengthening Kit

Post by Yelton »

I was really interested to hear about the "more traditional / OEM fix to the 'popped spot weld' problem" - I have a Z3 3.0i which looks to have 'popped' one spot weld and am keen to understand what this OEM fix is. Please tell
LaRy
Joined: Mon 12 Nov, 2018 17:47
Posts: 124

  Z3 roadster 2.8

Re: Randy Forbes Rear Diff Strengthening Kit

Post by LaRy »

Number one, I had about 8 spot weldings that had cracket, but no deformation in the chassi. Number two, just 192HP engine.

But after a discussion with an experienced BMW repair technicians, I change the partly cracked spot weldings for M8 bolts, good quality and used also washers. Has been working now for 8 years. The technician said that M8 bolts repair is better than any attempt to re-weld. It's stronger.
Yelton
Joined: Sun 27 Mar, 2022 07:48
Posts: 3

  Z3 roadster 3.0i

Re: Randy Forbes Rear Diff Strengthening Kit

Post by Yelton »

LaRy - thanks that's an interesting solution especially as it seems to have worked okay.

Any other solutions out there???
User avatar
Rocketman
Joined: Sat 24 Jun, 2006 16:46
Posts: 61

  M roadster S50
Location: St Neots

Re: Randy Forbes Rear Diff Strengthening Kit

Post by Rocketman »

Yelton, I eventually decided to get the job done by Classic Heroes. They prefer to keep any work done on cars to be as original as possible. They basically drilled out any suspect spot welds, filled the holes and re-spot welded and re-enforced with seam welds along the ridges in the floor pressings. The diff mount was also re-enforced by using doubled up original bracket. My car had a 'mid-life' refurbishment and this job was part of a larger programme of 'future proofing'. Contact Barney at Classic Heroes for a better description. Regards Jeremy
LaRy
Joined: Mon 12 Nov, 2018 17:47
Posts: 124

  Z3 roadster 2.8

Re: Randy Forbes Rear Diff Strengthening Kit

Post by LaRy »

z3pop.jpg
Hi, I just want to show how my replacement of broken spot weldings look like. As I say, has been working for 8 years, still checking every year for eventualy new broken spotweldings or lose bolts.
You do not have the required permissions to view the files attached to this post.
Post Reply