suspension probem but which way polyurethane bushes or standard bushes

[kagawa]

dear all, I hope you are all well, and in good form  I have found a fault on my jaguar s type 2002 suspension of uneven tyre wear on the inside edge , so I put my car on my local MOT ramp which is fitted with wobble plates and it wasn't long before I found the fault of failing bushes lower suspension arm. I can change them myself which is not a problem. but which way to go  polyurethane bushes or standard bushes..With standard bushes it seems quite straight forward but with  polyurethane bushes it is a science in its self  different colours represent different harshness and then there are  different colours by manufacture as well as quality between polyurethane bushes. its not a cheap option but is it  a better alternative.Polyurethane bushes can squeak if fitted badly and not lubricated on installation or poor design  but standard bushes can fail again and where do you stop , and as you are in the area you might as well do the drop links, lower ball joint  and anti roll bushes , any thoughts

regards to all liam

[JOE-DOT-COM]

Hi

I'd go with standard bushes, they generally last years and give the smoother drive

polyurethane bushes are good for fast road and track, but the main thing that put me off is, when they dry up, which does'nt take long, they can squeak really bad

cheers

Joe

[Lazlo Woodbine]

I fitted Polybush front anti-roll bar bushes to my S-type recently and have no complaints. Apparently the standard Jaguar ones are notoriously short lived, mine were completely shot at 100k and I reckon they had been for a while.

I've fitted polyurethane bushes to various cars and have never had any squeaks and although I have heard that they can I've never witnessed it myself.

In my opinion poly suits some bushes but not others. For example the front wishbones on VW A2 and A3 platform cars (Mk2/Mk3 Golf, Corrado etc.) swing around a horizontal fore-and-aft pin at the front with a bush that looks like a cotton reel but at the back have a vertical one and a bush that is shaped more like a donut.

I believe the front one is fine in poly as there's only rotational motion around the pin, the bush is purely an isolator. However the forces on the vertical back pin are trying to twist it side to side and so the bush is being severely deformed with every suspension movement. I have seen poly bushes fitted on these arms and the rear ones last no time at all, I don't think the load they're being put under suit poly at all. The material around the pin deforms permanently and quite quickly ends up allowing more unwanted movement than a standard void bush like the one in the picture. (Personally I use a poly on the front and a standard VW solid rubber (Golf R32 spec) one on the back whenever I rebuild these arms and they last.)

This is why I would happily put polyurethane all over the front of my S-type (my early type suspension anyway) where there is one motion (rotational) but am going with the original "pillowball" type on the lower rear arms because with normal use they have to flex around the pin.

 

[Russ68]

A comprehensive explanation there Ralph, thanks! I've fitted poly on my MGF, but generally the standard quality of nearly everything MG is worth upgrading! With higher quality jag bits I've been tempted to stick with OEM, but will bear your comments in mind when a change of mine come due. Did you press them out yourself and was this much of a job?

Cheers 

[Lazlo Woodbine]

Well it's only the conclusions I've drawn from messing about with such things.

I'd like to feel safe to assume that the Jag stuff is superior, to say, BL. But I don't. I've had some rubbish polyurethane stuff but some awful genuine stuff as well. Car manufacturers so rarely make these little parts themselves that I think it's best to assume that the manufacture of any OEM bush has been outsourced. I've had genuine VW bushes stamped Febi (absolute crap), Meyle, and Lemforder (good). I don't actually know which and/or how many firms Jaguar use for bushes so they may be good, but maybe isn't enough to make me pay higher prices for peace of mind.

The front ARB bushes are just clamped in. I say just because it's an absolute ballache of a job and I hope to never do it again. It looks quite simple but the clamp bolts are those horrible not-quite-a-bolt, not-quite-a-self-tapper sort of things. An absolute nightmare to get started in the captive nuts while fighting the ARB and trying to squash the new bush under the clamp. If it hadn't been getting dark I would have chiselled off or drilled out the captive nut and used a proper nut and bolt on it.

 

 

[Russ68]

Understood re the subcon of parts, but to date Jag bits seem a lot better! Took one of the door cards off last year fully expecting every trim clip to disintegrate (like the MG!), and they didn't, bought some spares and the only ones I broke were the spare ones, not the originals!