Trailing arm bushes

[Clifford Pope]

Here we are:

http://www.ebay.co.uk/itm/triumph-stag- ... SwKtlWhnVn

[Dave B]

Here we are:

http://www.ebay.co.uk/itm/triumph-stag- ... SwKtlWhnVn

Its been a good few years since I did my 2500 with polybushes from CW, and this is how I remember them, half a bush pushed from each side of the casting, then insert the stainless steel tube. Simples!

[Forkie]

Um yes ok that makes more sense - a split bush slid in,in half,to each recipient. which is what had to happen to mine to fit them,albeit via a hacksaw as there was no way a single bush was going to be passed through. ( In our opinion).
But that doesn't answer my current position with arms fitted,but with 'opened up' shackles,that I don't feel will close up to original size when fully tightened due to the central tube being 'hard up' as they stand. i'm happy that nothing will happen in the future - I would just prefer a second opinion.

[tony]

Could you measure an unmolested shackle and have turned or grind the centre bush to length ?
Tony.

[Clifford Pope]

Something seems wrong with those bushes and pin - wrong car perhaps?
I can understand that the bush itself should be quite a squeeze - indeed when I did mine I used a small G-clamp to nip the edges together just to get it started as I re-engaged with the shackle - but surely the tube should be exactly the width of the shackle? If it is too long then the bush itself won't be being squeezed sufficiently when you tighten the bolt?

There's a difference in principle between an original bonded bush and a poly bush. With a bonded bush the pin locks the tube, so the inside of the bush is fixed to the car, and the outside is tight in the housing, so the rubber twists as the suspension moves.
But with polybushes the tube is not bonded, so if the bush is going to do anything it itself has to be squeezed by the shackle sides. They don't just rotate on the tube, surely?

[Forkie]

Have been out and took some measurements this eve. Internal of a shackle appears 62-3 mm. An old unmolested bush and tube comes in at the same. The new bush and tube measurement appears the same ( a little tricky to measure as both arms are now in-situ).

So I am even more confussed that I have had to open up the shackle ( should add at this point it is mainly the stubbier,outer shackle on both sides - the inner one not so bad) at the open end by 12 mm (open end now measuring 75mm) to enable siting the arm back far enough to line up the holes to fit the bolt through - which was still a rubber mallet job.

I'm just not sure whether to carry on rebuilding and see what happens when the time comes for tightening them up or....

At this stage when the arm is moved up and down the tube and bush move.

Will try and put up a few pics.

The only thing I can think of is there is absolutely no give in these black polys which is why there appeared no chance of compressing them down to fit through the arm. Has anyone else fitted these black ones?

[Mike Stevens]

I've certainly had to 'ease' the shackles out in the past to fit them over the newly fitted bushes, but when tightening up the bolt, they have gone back to the correct overall dimension. If that is not the case with yours, I would perhaps think they weren't the right ones. Maybe.

I don't think I've fitted the black ones, just the dark blue ones from Chris. They went in as a single bush with the tube being fitted afterwards.

Cheers,
Mike.

[Forkie]

Some pics :

[Forkie]

Am hoping the pics give an idea - first two maybe not but hopefully the third gives an idea - unfortunately a combination of not a lot of 'headroom' , my focusing not being brilliant due to hayfever season and an ever growing mid-drift made close up photography a trifle challenging this evening

Am aware of 'opening up ' being a course of action for some but how much...Am wondering whether to try G clamping the bend back before bolting up - as I see it at present with the bend to the open end - surely the bolt head is just going to cut into the bent out portion,as the bolt head is not 'seating' to a flat surface but an angled one. If you see what I mean.

[tony]

That's a bloody mile away. you'll have to either shorten the tube or get the correct one's IMO, and straighten the shackle bracket.
Tony.