Jump to content

Front wishbone bushes


Recommended Posts

Repro parts strike again.

I'm refurbishing the entire front suspension on my GT6.  I have now got to the rubber bushes for the wishbones, four each side.  On assembly, I thought the rebushed wishbones felt loose on the 3/8" pivot bolts.  I checked with the old bolts, and some new ones.  Both loose.  So I took my digital calipers to the bushes - the old ones are 0.375" ID, the new ones are 0.388" - or, in modern, old are 9.55mm, new are 9.90mm.  No wonder they clatter around.  We have Rimmers (and no doubt all the others) supplying metric parts as a 'close enough' replacement for Imperial parts.

The question is, are these close enough, though?  Surely even tightened to torque, with the forces on them these are going to clunk around on the pivot bolt?  Or are they OK to use?  The rubber on the old ones is not great so I'm not keen to put them back in, and I definitely do not want to use Polybushes.  Don't ask, I just don't like them.  I don't suppose anybody knows of a supply of Imperial bushes?

Link to comment
Share on other sites

The part number on the old bushes is 'Clayflex SAB930'.  Clayflex appear to be long gone.

I've just found some SAB930 bushes at AVMR (Anti Vibration Methods (Rubber) online, so I'll try some of those and report back.  They spec them with a bore diameter of 9.6 +0.08/-0.05mm, which is better than 9.9 but not quite as tight as the originals.  Worth a try at £2.23 each, and at least in the applications they list 'Triumph cars: unknown models' and 'Ford & Alder cars.  Original part number: 8?04612'.  Interesting.

Link to comment
Share on other sites

I thought the bolt to sleeve clearance shouldnt matter as the sleeves are clamped in the brackets by the bolts. The sleeves certainly should be free to move on the bolts and to get them in the right position should be clamped up with the car weight on the wheels.... 

Link to comment
Share on other sites

OK - do you think the clamping effect will be enough to hold the inner sleeves firmly with no movement?  If they do, I suppose things should work OK... My concern was that on loose assembly the wishbone arms can really wobble all over the place.  Doesn't seem ideal to me.

Link to comment
Share on other sites

Surely everytime you go over a bump, the car goes up in the air, the weight is transferred from the bottom and the bolt rises up in the bush? Might not be a big deal but over time it adds up.

Original bushes were Metalastik, the part number on them is 13/1309. Used on a lot of cars of the period. I've seen sellers online selling modern replacement bushes with the centre tube diameter as high as 1cm; last ones I bought from James Paddock seem to be 0.375 diameter - it might be worth giving them a ring and asking if they'll confirm? Otherwise, you could just use a bigger bolt... :)

DSCF0054.jpg.dfb35957ce67290042f3855661ab7978.jpg

Link to comment
Share on other sites

13 minutes ago, Colin Lindsay said:

Surely everytime you go over a bump, the car goes up in the air, the weight is transferred from the bottom and the bolt rises up in the bush? Might not be a big deal but over time it adds up.

Original bushes were Metalastik, the part number on them is 13/1309. Used on a lot of cars of the period. I've seen sellers online selling modern replacement bushes with the centre tube diameter as high as 1cm; last ones I bought from James Paddock seem to be 0.375 diameter - it might be worth giving them a ring and asking if they'll confirm? Otherwise, you could just use a bigger bolt... :)

DSCF0054.jpg.dfb35957ce67290042f3855661ab7978.jpg

A bigger bolt would mean opening up the holes in the mounts - no going back then.  I wouldn't want to do that.

Link to comment
Share on other sites

58 minutes ago, Colin Lindsay said:

Surely everytime you go over a bump, the car goes up in the air, the weight is transferred from the bottom and the bolt rises up in the bush? Might not be a big deal but over time it adds up.

 

Surely neither the bolt nor the inner metal sleeve should be moving when tight? So even if the sleeve is a slightly rattling fit on the bolt when all is loose, when all is nipped up, laden or unladen the only movement should be between the bush and the clamped sleeve?

Gully

Link to comment
Share on other sites

2 hours ago, Colin Lindsay said:

Surely everytime you go over a bump, the car goes up in the air, the weight is transferred from the bottom and the bolt rises up in the bush? Might not be a big deal but over time it adds up.

The force downwards is a lot less plus the rubber cushions so if done up properly they wont move. The same design is used on many components like trunnions, radius arms, rear diff mountings....

Link to comment
Share on other sites

51 minutes ago, johny said:

The same design is used on many components like trunnions, radius arms, rear diff mountings....

It may be, but it's probably used with the correct sizes of bolts, which is the problem. It might not make any difference to many, but it still annoys the whatever out of me, so I'd be looking to source the proper sizes. Just me!

Link to comment
Share on other sites

Just fyi, the new bushes from AVMR arrived today and are spot-on.  ID of the central bush is 0.376" and - to my surprise - they are marked 'Clayflex' with the part number given above.  So they are the same as the old ones I am removing.  I have a suspicion these may be the originals, as they have clearly not been changed for many years.  I also have three large folders full of every invoice relating to my car since the previous owner bought it in 1976 (it's a '73/4), and there's no mention of suspension bushes being changed.

So I'd say the Rimmers bushes are ones to avoid!

Link to comment
Share on other sites

It's like bearings - if I can find the bearing type number I'll buy from a bearing specialist, not the marque specialists.  It's usually cheaper and there's more choice.  I guess when they design a car like this they go for a readily-available industrial bushing, nothing bespoke.  All you need is the dimensions.

  • Like 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...