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Poly bushes in suspension?
Hi guys,

In the middle of a much needed suspension overhaul and I was thinking about improving the handling and long term reliability with poly bushes in the leaf springs.

Anybody else done this? If so how do you find the handling? Any help and advice as always very much appreciated.


Unlikely to change the handling unless your current pins and bushes are really shot.
Maintenance free once fitted, possible less road noise, but it is an old car, how modern do you want
it.l have polybushed the rear springs on my Morgan, only because the pins seize in the metalastic bush, then the whole lot moves and wears the eyes in the Chassis.
One of the joys of the Seven is the traditional engineering. A practical person with a lathe can fix much often at very little cost. The front axle has to be located very rigidly fore and aft. Sorting this without resort to metal to metal contact is not straightforward. Non metallic bushes generally require more room than is available.
The lubrication requirements for normal hobby use are negligible, very simple in any case, and part of the fun.
I concede that the sideways location of the rear axle is not well suited to metal to metal. The spacing betwen spring eyes varies markedly with bumps and turns.
The handling peculiarities of Sevens are somewhat beyond such minor tweaks!
The only place that I use different bushes is on the shock absorber links.
Mine are delrin I have seen tufnol used as well.
The brass bushes in the axle eyes will last for years with a bit of grease and give good location.
Polybushing anything is a total waste of time.

The vast majority of Poly Bushes offered are made of inferior material & will wear & crack much worse than the correct rubber item.

While these were "the thing to use" a few years ago, those in the know are switching back to rubber.  It looks much better than a purple, red or fluorescent green bush & doesn't crack & loose its elasticity.  While there are serious benefits swapping to rigid materials like Tufnol or even Aluminium in competition cars the drawbacks hugely outweigh the advantages in normal road use.

And finally, all that vibration & movement has to go somewhere, it doesn't just vanish!

[Image: 20130722_105215_zpsf11d202b.jpg]
I agree with Mk I Mark… don't use those modern 'stiff' bushes.. I've had them in the distant past in my Citroen AX Sport (a nice homologation special on sizzling rorty twin Solex carbs )… together with yellow Koni shocks; they made me negotiate roundabouts and other bends at quite elevated speeds…. however the guy who bought the car from me with more serious rallying in mind discovered that the suspension pick up points had sheared from the bulkhead…...

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