Rear Strut Tube Repair

[Vanden Perre]

Hello,

For the second time in one year I have had a problem with one of the rear strut tube of my S3. The thread on the top of the tube is badly damaged and the cap is no longer properly fixed on the tube allowing the damper to move out of the strut tube. Twice I have had the cap welded on the tube but I would like to fix it definetely.
The thing is that I doubt it is possible to remove the tube from the bearing housing as it is a heat shrink fit assembly. I don't want to have to buy a new bearing housing (and I am not sure I can easily find one for an S3: Paul Matty mentions only spares for 68 on models and mine is 2 years older) and I am looking for a cheap but proper fix.
Any suggestion?
Any comment on my idea: why not cut out the damaged threaded extremity of the tube have a new extremity machined with the proper inside thread (or maybe even easier buy a new strut tube and cut the extremity) and after that having a good welder (pipe fitter for example) welding the new threaded extremity on the assembly. Together with a new cap, it seems to me that it could do the job. What do you think?
Thanks for your comments.

Olivier

[john.p.clegg]

Olivier

If you're going to go the trouble of welding two tubes together why not kill two birds with one stone and use a threaded sleeve to cover the join (adjustable perch for 2 1/4" springs)?

John

[johnsimister]

There's a pair of rear uprights on eBay UK at the moment which might suit. You would need to fit new wheel bearings. Item no is 260441430981.

Hope that helps.

John

[enskr]

Olivier
It is possible to replace the tubes - Paul Matty did both of mine last year. They warned me that it would be difficult and that there was a risk of irreversible damage to the aluminium housings, but they managed to do them both without a problem, using heat on the casing and ice in the tube. Wasn't all that cheap though - the tubes were about ?120 each for starters.
Careful when you refit them though - despite being careful I cross threaded one of the retaining nuts at the top of the tube and nearly had to have it all done again - it's a very fine thread and easy to do.

Personally I don't like the sound of welding 2 tubes together, but I guess if it was done carefully it should do the job.

Kevin

[512BB]

Olivier

Any REPAIR to the top of the strut tube is a bodge in my opinion, and if it were my car i would not entertain it.
Either find yourself a competent workshop and new or secondhand tube and have the replacement fitted, or, much simpler, buy another GOOD housing and tube.
If you let me know what side you need, i MAY have an early unit spare.

All the best,

Leslie

[ill_will]

One other problem you might have is welds protruding into the inside of the tube in places: clearance is quite tight and you might not be able to fit the dampers without spending some time filing down any welds that have come through to the inside.

will

[andyelan]

Hi Olivier

Just a thought but how about reversing the original design. Make an externally threaded sleeve to slide over the tube and be welded in place, then make a internally threaded cup shaped nut to hold the shock.

On my car (a '73 Plus 2 ) there's a 2.25" diameter x 1" long spacer pushed over the tube to limit the suspension travel. If I were to do a repair like this, I might consider making this spacer and the shock retaining nut as one item.

Andy