Polyurethane, not stock.

Here is pic of one of them being extruded from its proper location.

I have on hand new, OEM style bushings from manners (IIRC) in the UK. (Thanks, Greg!)

I know NOT to tighten the nuts fully until the car is on the ground and has been bounced up and down several times.

The car only had 53K miles on it, not enough to justify new bushings. Based on other "modifications", it seems the previous owner was trying to make the car (an H&E convertible) into some sort of track car, or at least, performance car, thus the unnecessary switch to poly bushings.

The whole front suspension will be disassembled, cleaned and painted prior to reassembly.

Doug

 

Good decision. You will notice the difference.

 

Unfortunately not all poly bushings are high quality. Even IF you decide they're the right choice you have to be very selective in buying them.

We became aware of this 20+ years ago with rack bushings. Vendors were selling sub-grade poly bushings that turned to goo after just a year or two.

Cheers
DD

 

I discovered that merely Bouncing the car was insufficient to settle the suspension no matter how many friends you get on the bumper. One needs to DRIVE IT AROUND A BLOCK OR 2, preferably over a speed bump (nothing bad will happen in that short distance).

When you do this, you will see the front drop about 2 inches before your very eyes. And Then you know it's seated at the correct ride height and the bushings aren't stressed in incorrect positions, and you won't need to mess with it again for another 35 or 40 years.

And then do not jack it up again to tighten the nuts, do it from the ground (I found a pit) or the suspension will only drop out of position again.
(I'm so adamant about this, one of my Hobby Horses in fact, cuz I've seen it done wrong so many times and people wonder why even their Metalastik bushings lasted only 3 years; I could name names!)
(';')

 

Or drive it up on blocks at the front to get access; but as LnR says, it MUST stay on its own weight after the settling run when you tighten up the castellated nut.

The other point about the poly lower bushes, apart from their inability to reproduce the famous Jaguar ride/handling combination, is that they work in a different way from the metalastics. The metalastiks work by allowing the rubber to deform with the suspension movement, which is why tightening at their midpoint is so important if they are not to tear. None of the surfaces actually move; not the rubber against the inner steel core tube, nor the bush/suspension eye surfaces. This is why the special washers have knurled surfaces to grip the tube and the rubber is bonded to that tube.

Polys, by contrast, are meant to actually swivel about their central steel tube, the tube being fixed by the tightening process and the suspension arm eye/bush surface also not moving; the suspension movement SHOULD be accomodated by the 'bearing' surface between the poly bush inside surface and the steel tube, which should be able to move as the suspension does. This is why lubricating this poly/steel tube surface is advised to prevent squeaks. I believe that the problems with poly lower bushes sometimes arise because the Jaguar special washers that grip the inner steel tube ALSO tend to grip the ends of the poly bushes, thus preventing their ability to swivel about the tubes; so they have no option but to break up.

 

That all makes sense. Simply dropping the car down from some lifted position, sets the tires on the ground with a slightly narrower track, as the tire contact patch can't spread outward like it does when the tires are rolling, allowing the track width to return to normal and de-stressing the bushings.

I have a four post lift, so yes, its easy to drive the car onto that for final control arm nut torquing. Working on my back, under a car, has lost some of its appeal as i grew older.

Doug