LOWER WISHBONE

[bobwhittaker]

Put about 50 miles on the car yesterday with the solid nylon bushes in the front suspension. Certainly a different feel to immediately
prior to fitment and if anything a slight improvement, with no noticeable adverse effects on harshness / handling. Being realistic the
slight improvement could well be due to replacing the three torn , out of four, bushes on the lower arms. The next question is how
long will they last ? I have stated previously I intend monitoring the situation closely regards cracks and bush condition.

[Westfield 129]

Have you considered Delrin, with an internal sleeve to support the suspension bolt? Make the sleeve just long enough to clear a pair of thrust washers so the bush and arm remained centered in the suspension mount. This is a suspension bush design that has been around for about 30 years, and is proven technology.

The material that you are using currently would also work well with a proper sleeve.

This will allow you to tighten down the suspension bolt, and allow the suspension arm to rotate around what is essentially a fully lubricated bushing. The parts should last indefinitely if they are regularly lubricated (you can drill and install a grease nipple. The lubrication hole should extend through the entire bush to the center sleeve. You can machine a groove around the length of the sleeve to distribute the lubricant, like a single thread).

I have extensive experience with delrin bushings of this design (about 300,000 miles) on various road and competition cars. I have yet to wear out a set, and they don't distort over time.

My experience with early experiments resulted in oval holes around the bolts if no sleeve was used to distribute the load about the entire internal bore of the bushing body. Cracking often followed.

Or, you can just get a set of the latest Westfield poly bushes, which have a center sleeve, thrust washers and will likely last a very,very long time. Much longer than the metalsitic bushings.

If you try a set of ProFlex bushings, make sure that the center sleeve fits within the suspension mount tabs.

[bobwhittaker]

Have now done some 450 - 500 miles with the repaired wishbone and one piece nylon bushes fitted at all eight positions on
the front suspension. Whilst upgrading the front pads ( See other thread ) I inspected wishbones and bushes closely and all
looks good. I had already replaced the rear suspension metalastics with one piece bushes ( Previous thread ) and the car
drives well and is a little less harsh on indifferent road surfaces than it was with the metalastics all round, with no loss of
feel or stability.

[Westfield 129]

If you are using a non compliance bushing in the rear, you have to not only check the bushes for ovaling (not a problem with poly compliance bushings), but also frame cracking.

The equal length 4 link has quite a bit of binding built into its design (in roll, the arms push, pull and lock up), and can, without some compliance in the bushings, crack the chassis mount for the rear trailing arms. I have seen this on two cars, including my own, which required replacing both rear suspension mounting points.

If you drive the car hard, you might notice that it will transition to over steer quite a bit more quickly, and you may find traction problems off the corners due to the decrease in articulation with solid rear bushings.

I ran rod ends on my car for quite a while (no compliance), and found more problems were created in both the chassis and the handling than were solved. Having to replace the metalistics on a regular basis was a better option than having to re weld the chassis, and deal with somewhat dodgy handling at the limit.

In the end, I found that installing 4 proflex bushings fixed most of the problems. The remaining metalistics that I have at the axle end of the rear suspension are lasting quite a bit longer due to the increase in compliance of the Proflex bushings mounted to the chassis end of the arms. '

i have another set of the Proflex bushings for the rear, but they will require a little modification as they are marginally too wide to fit within the rear axle suspension arm mounts.

I have been using the metalistics up front, with minimal torque on the suspension bolts, and the bushings have been lasting for years without failure.

[bobwhittaker]

I hear and understand what you say about the the geometry of the rear suspension arms and the problems non compliant
bushes can give in this location. The material I have used appears to be compliant, although I don't have any hardness
figures. Being aware that problems can occour is a good start and it is a simple job on the Eleven to keep an eye on
things,both front and rear. I hope to be able recognise what is happening and intervene before any drama occours.
Cheers BOB

[Pluscat]

Take attention guys!
I have had the same problem!
A few years ago the righthandside lowerwishbone on my eleven cracked too.
I discovered this by coincidence when I was working on my westfield eleven series1

Had the wishbone welded and check regularly eversince.

I think this is a something more than an incident, and more like a structural design flaw

I recommend all owners to check the wishbone regularly!!!!

You wouldn't be the first lotus driver to get killed when a wheel came of a Lotus....