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Mx5 rear upright sleeve
Slimy38 - 2/12/13 at 03:58 PM

I need to put a sleeve in the lower fixings of my MX5 rear upright. Courtesy of Skov's blog (http://mx5-haynes-roadster.blogspot.co.uk/2012/02/rear-upright-holes.html), I know it's a 14mm OD, 1mm tube, but I was wondering what is the best stuff to use.

My initial thoughts are to follow Skov and use stainless, considering how much hassle it was to remove the bolt from the donor I don't want to be in that position again. Alternatively, I could use normal steel, let it rust itself in place, and then just grease the bolt going through it. Or I could use aluminium, but I'm wondering whether that would be a good idea.

I did also wonder whether penny washers would be good on the outside edge of the bushes, so the bush was sliding on new smooth metal rather than old rough upright. Is that overkill?

chrism - 2/12/13 at 09:52 PM

I wouldnt bother with aluminium as I think thats what the uprights are made of and what causes the problems in the first place, some reaction happens between the ali and the steel that causes the bolts to stick, hence putting a steel or stainless sleeve in it and then the reaction wont happen between the bolt and the sleeve but may still between the sleeve and the upright but at least the bolt will come out.

Slimy38 - 3/12/13 at 08:26 AM

quote:
Originally posted by chrism
but may still between the sleeve and the upright but at least the bolt will come out.


That's kind of what I was thinking, the uprights are never going to return to an MX5 so I'm ok with the sleeve becoming a permanent part of the upright. And I did wonder whether mixing metals was a bad idea overall. Bog standard steel it is then!

indykid - 3/12/13 at 12:51 PM

The uprights are iron, not aluminium alloy.

Sleeve it with whatever you fancy, use plastic conduit if you're still concerned, but it's worth remembering that the upright bolts sieze in mx5 uprights after probably 100k miles of year round use.

A bit of copper slip on assembly will be more than sufficient to prevent further siezure for the life of most kits. The tube is more likely to trap water and cause the centre of the bolt to corrode.

Slimy38 - 3/12/13 at 02:10 PM

quote:
Originally posted by indykid
The uprights are iron, not aluminium alloy.

Sleeve it with whatever you fancy, use plastic conduit if you're still concerned, but it's worth remembering that the upright bolts sieze in mx5 uprights after probably 100k miles of year round use.

A bit of copper slip on assembly will be more than sufficient to prevent further siezure for the life of most kits. The tube is more likely to trap water and cause the centre of the bolt to corrode.


The sleeve isn't for corrosion resistance, it's to fit a 12mm bolt in a 14mm hole...

I just didn't want to add yet another corrosion factor into the whole thing. Hence the query about material.

[Edited on 3/12/13 by Slimy38]

chrism - 4/12/13 at 12:47 AM

quote:
Originally posted by indykid
The uprights are iron, not aluminium alloy.


my bad I thought they were ali and that was the problem with the bolt seizing.