Lotus Elan

Polyurethane bushings

PostPost by: bengalcharlie » Sat Nov 05, 2011 8:40 pm

I also bought a set of autobush suspension bushes a few years ago. They are inexpensive and easy to fit. I did not notice any real difference in the ride, defenitely not harsher but the advantage of easier to fit and remove ( you only need a bench vice) and the fact that they are not affected by oil/grease make it an easy decision. I also bought the front bushes but they are still on the shelf waiting to be fitted one day.
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PostPost by: RotoFlexible » Thu Mar 17, 2016 12:20 am

Reviving this old thread to report that I had to replace the rear-end inner Autobush wishbone bushings after about eight years and 17,500 miles of normal road use. I started to hear and feel a clunk in the rear when engaging and disengaging the clutch. Twisting a rear wheel side to side produced a slight movement that I could see in the inner wishbone mounts. When I removed the wishbones, the wear between the stainless steel sleeves and the bushings was obvious, and some of the bushing flanges were badly mangled.

I got Superflex bushings from RD Enterprises. Fitting them was a pain for the same reason as the Autobush bushings: the spacing of the wishbone ends is slightly less than the spacing of the brackets that hold them. (This is probably why the old bushing flanges were mangled.) I had to reduce the thickness of the inner bushing flanges by more than a third to get them to fit. At least I didn't chop off any body parts this time...

The new bushings have eliminated the clunk and noticeably improved the feel of the car - it seems tighter and more solid. I hope they last a bit longer than the last set.
Andrew Bodge
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I love the sound of a torque wrench in the morning. Sounds like... progress.
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PostPost by: Sea Ranch » Thu Mar 17, 2016 12:34 am

Thanks for updating this thread with your experience, Andrew. I haven't yet purchased new bushes yet (all 16 original factory bushes are pressed out - that was interesting :mrgreen: )

I can almost understand from your explanation what was not the right dimension in the new parts, but would love some further clarification (of course, a pic would be even better . . . :wink: )

Thanks so much . . .

(Still considering stock style bushings as I'm after the absolute best NVH performance I can get)

Randy
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PostPost by: RotoFlexible » Thu Mar 17, 2016 12:06 pm

Randy,

Yes, it's difficult to explain the dimensional problem in one sentence. Each bracket is wide enough to accommodate its wishbone end with the bushings installed. However, the center-to-center spacing of the brackets is slightly (about 1/8") wider than the center-to-center spacing of the wishbone ends. Whether this is the fault of the wishbones or the (Lotus replacement) chassis, I cannot say. So, with the bushings installed, there is interference between the (longitudinally) inner bushing flanges and the (longitudinally) inner bracket flanges. Reducing the thickness of the inner wishbone flanges allows the wishbone to be fitted, with difficulty.

Each bushing consists of a pair of top-hat-shaped halves each of which is inserted into one end of the wishbone end. The picture on Ray's site doesn't show this correctly. The "brim" of the "hat" is the flange I'm talking about.

Hope this helps, and good luck when you get to this step.
Attachments
win_20160317_08_48_55_pro.jpg and
Old bushing with mangled flange
Andrew Bodge
'66 Elan S2 26/4869
I love the sound of a torque wrench in the morning. Sounds like... progress.
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PostPost by: Sea Ranch » Thu Mar 17, 2016 2:10 pm

Thanks, Andrew, and I totally get it now. Good description.

And it reminds me of what Col Croucher says on his webpage regarding making and installing bushings, and the correct torque to be placed on the inner steel tube which the bolt goes through. He calls it a crush tube, and I believe the idea is that there should be a certain squeeze on that tube, but not much on the bushing flanges, and there should be pretty free movement/rotation of the swing arm, etc. Interesting read, in any case . . .

Thanks again,

Randy
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