A-frame bushes: progress report...
Discussion
Right, I've finally managed to get somewhere with sourcing original-spec. bonded rubber bushes for the A-frames (and the diff. cradle: the diff sits on two more of them although the bushes are hidden by the brackets).
I approached a distributor of bushes with a view to finding some that were close to the correct dimensions and either shortening them or reducing the diameter as appropriate. Another option was to find some the right size with a larger bore and drill out the holes in the chassis to accommodate larger bolts, but I'd prefer not to do that.
In the course of discovering what was available it was suggested that if I was prepared to fund a short production run, then bushes could be made to the exact dimensions required. Of course I asked them to investigate the costs to do that - and it turns out that the tooling already exists to do it!
The minimum order quantity would be 20 (effectively two car sets including the diff cradle)... but they want £24.95 EACH BUSH plus carriage and VAT - delivery in approx. 6 weeks.
So comparable with Polyurethane I suppose, but as the nearest thing I can find can be had for more like a fiver, if I can work out a quick procedure to cut them to size I could probably make them available to the discerning Wedger for a more sensible unit price
I approached a distributor of bushes with a view to finding some that were close to the correct dimensions and either shortening them or reducing the diameter as appropriate. Another option was to find some the right size with a larger bore and drill out the holes in the chassis to accommodate larger bolts, but I'd prefer not to do that.
In the course of discovering what was available it was suggested that if I was prepared to fund a short production run, then bushes could be made to the exact dimensions required. Of course I asked them to investigate the costs to do that - and it turns out that the tooling already exists to do it!
The minimum order quantity would be 20 (effectively two car sets including the diff cradle)... but they want £24.95 EACH BUSH plus carriage and VAT - delivery in approx. 6 weeks.
So comparable with Polyurethane I suppose, but as the nearest thing I can find can be had for more like a fiver, if I can work out a quick procedure to cut them to size I could probably make them available to the discerning Wedger for a more sensible unit price
Ian
Put me down for at least a couple of sets no matter which type you go for!
I will be needing them for my perposed rebuilds in the next year or so. Better to get them now rather than find I can't source them when I need them.
Mind you when I did num 1, I used some from a Cerbera which fitted a treat (Via Mr Heath) I am not certain which part off the Cerbera the bush came from!
Andy
Put me down for at least a couple of sets no matter which type you go for!
I will be needing them for my perposed rebuilds in the next year or so. Better to get them now rather than find I can't source them when I need them.
Mind you when I did num 1, I used some from a Cerbera which fitted a treat (Via Mr Heath) I am not certain which part off the Cerbera the bush came from!
Andy
My mitre saw can go through steel and rubber no problems, and that cost me £100 from screwfix. I expect you can get similar ones for chopping only (no mitreing) even cheaper, or a chop tool which is essentially an angle grinder mounted on a swivel.
If doing a run all you then need is a stop set up on the saw base and a clamp to hold the piece (no fingers please!) it will take a minute per bush if you take it slowly.
If doing a run all you then need is a stop set up on the saw base and a clamp to hold the piece (no fingers please!) it will take a minute per bush if you take it slowly.
Wedg1e said:
Surely No. 1 isn't an A-framed car?
Hi IanCorrect but a lot of the bushes are the same. TVR just used them in different parts.
The only bush I am not certain were they come from are a set which hold the diff frame at the rear were it attaches onto the chassis. The bushes sit inside the rear of the chassis and the bolts for the frame go through them into the diff frame!
Andy
adam quantrill said:
My mitre saw can go through steel and rubber no problems, and that cost me £100 from screwfix. I expect you can get similar ones for chopping only (no mitreing) even cheaper, or a chop tool which is essentially an angle grinder mounted on a swivel.
If doing a run all you then need is a stop set up on the saw base and a clamp to hold the piece (no fingers please!) it will take a minute per bush if you take it slowly.
Good idea, but the inner and outer sleeves are different lengths. The inners are longer, otherwise wen you clamped to the chassis you'd nip up the outer at the same time.If doing a run all you then need is a stop set up on the saw base and a clamp to hold the piece (no fingers please!) it will take a minute per bush if you take it slowly.
Mr Tank said:
Hi Ian
Correct but a lot of the bushes are the same. TVR just used them in different parts.
The only bush I am not certain were they come from are a set which hold the diff frame at the rear were it attaches onto the chassis. The bushes sit inside the rear of the chassis and the bolts for the frame go through them into the diff frame!
Andy
As far as I'm aware the A-frame bush is only used there and for the diff lower mounting to its cradle; the cradle/ subframe is bolted rigidly to the chassis... unless of course your car's different Correct but a lot of the bushes are the same. TVR just used them in different parts.
The only bush I am not certain were they come from are a set which hold the diff frame at the rear were it attaches onto the chassis. The bushes sit inside the rear of the chassis and the bolts for the frame go through them into the diff frame!
Andy
At the rear my car has two lengths of solid tube welded through the box rail, through which the rear cradle bolts pass.The chap at David Gerald told me that particular bush was a TVR special made by a long-defunct firm in Lancaster. I can believe there was a bush maker in Lancaster; after all it's just up the road from Leyland!
adam quantrill said:
How much difference do you need - a mm or two? (At each end?)
Aye, about 2.5mm. You could cut them flush and fanny about with washers but it'd be exactly that: a fanny-on.A lathe will whip through the outer shell easily enough; it'll be getting the rubber out of the way that makes the mess
Piece of piss then Ian.
Get an expanding bolt ( the type you use in a wall or masonry). Insert into inner sleeve. Get a few washers and pull the inside sleeve one direction against the outer sleeve so it's 2.5mm inside (stretching the rubber).
Then get the chop saw and saw it off flat.
Release the bolt, swap ends, repeat the process so the outer is the correct length. The inner will be 2.5mm longer on both ends. Simples!
If you send me one I'll do it here and send it back for inspection!
Get an expanding bolt ( the type you use in a wall or masonry). Insert into inner sleeve. Get a few washers and pull the inside sleeve one direction against the outer sleeve so it's 2.5mm inside (stretching the rubber).
Then get the chop saw and saw it off flat.
Release the bolt, swap ends, repeat the process so the outer is the correct length. The inner will be 2.5mm longer on both ends. Simples!
If you send me one I'll do it here and send it back for inspection!
Right, I sold the grandkids into slavery (haven't told their mother yet) and bought me some bushes to play with:
Essentially they're the same OD and ID as the originals, plus or minus a few tenths of a mil, but a good bit longer:
A quick measure with the Very-near caliper showed how much needed removing and from where (there's more of the inner sleeve protruding on the new ones, as well as the outer sleeve being too long) and a few minutes tickling with the lathe got to this:
Note the short lead-in taper on one end, this is to aid starting the bush in the bore when pressing it in. So one down, nine to go...
Essentially they're the same OD and ID as the originals, plus or minus a few tenths of a mil, but a good bit longer:
A quick measure with the Very-near caliper showed how much needed removing and from where (there's more of the inner sleeve protruding on the new ones, as well as the outer sleeve being too long) and a few minutes tickling with the lathe got to this:
Note the short lead-in taper on one end, this is to aid starting the bush in the bore when pressing it in. So one down, nine to go...
Fitted full new rear set of zinc coated grade 5 high tensile bolts on the 390SE late last year. Got all the bolts I needed from Westfield fasteners. £40 for all bolts including VAT and postage.
http://www.westfieldfasteners.co.uk/UNC.html
http://www.westfieldfasteners.co.uk/UNC.html
Hmm I was hoping I might be able to pick something up in Cambridge tomorrow to use but maybe that's too optimistic.
On the other hand I have a vague feeling there might be one lurking in the garage, although that might be a trailing arm one.
Thanks for the offers if I can't find anything I might take you up on it Andy.
At least I'll spend a few hours taking it to bits - that's usually the hard part.
On the other hand I have a vague feeling there might be one lurking in the garage, although that might be a trailing arm one.
Thanks for the offers if I can't find anything I might take you up on it Andy.
At least I'll spend a few hours taking it to bits - that's usually the hard part.
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