Beware continued

[MACCA.GLM]

Hi all

Just to keep you posted on the problems with the wishbones moving over the bushes( poly type). The problem is now solved.As I said earlier bigger washes are now fitted approx 32mm od 13mm bore and 1 1/2 mm thick. I also had the steering rack reconditioned by Kyley Clinton Birmingham . My rack was a total mess with all parts except the tube scrap. I have all the worn parts to show for it.They did a great job and I'm glad I took it to them as I could have been in big trouble.Even the tie rods had corroded on the threads and were scrap.Anyway a new set of boots Nangkang 155/70/13. Recommended by Tony Thompson lotus.The car now handles as it should with pinpoint accuracy. Just the rear to sort Later on in the year.

Cheers

G

[l10tus]

Wouldn't be happy to think my wishbone bushes were that sloppy so as to have to rely on metal washers stopping them sliding about!

The washers coming into contact with the metal wishbones is very undesirable!

Can't imagine the clanks, bumps and bangs that will transmit through the steering!

In my opinion, from experience, never ever use poly bushes where metalastic rubber ones were originally used.

Also, and probably most importantly, part of the inherent turning resistance provided by the rubber/metalastic bush, contributed to the original design of the spring / damping resistance in the suspension steering set-up.
Something poly bushes do not do.

Steer well clear of "upgraded suspension parts" that don't work.

Poly bushes may have their place on other cars, and are relatively easy to fit, but therein lies the issue, people think it's an easy upgrade, but are in ignorance of the correctly intended original design.

Buyer beware!!!!

When you find out remember who told you, eh!

[miked]

I have to disagree. I have had the original bushes migrate in both planes. Most peolpe put washers with original bushes as a safety feature for if they tear.
The key thing here is the fact that a lot of the so called new original bushes are of poor qualty. Nothing like the original ones that were really good.
The late Mick Miller was so sick of changing them after 12 months on a restored car that he commissioned the poly ones. Sue will verify. The worst culprit on the car is the rear outboard A frame ones. Hardly any meat. My first Plus 2 back in 96 was gouging the inside of the rear wheel. For and aft movement under braking and acceleration.
I have run Elans and Plus 2's for thousands of miles on poly. It is more about the correct fitting of them. They are a bearing and need to be treated as such.
I run a 180bhp Zetec s4 with them. Probably due for a check now after our Scottish trip. They have been on for about 7 years.
I am no mechanical engineer but would have thought the geometry of the A frame and the whisbone naturally transfer loading onto the axis of thr mounting bolts.

I don't like to disagree but do you want to worry the people on here who have them on their cars?

[661]

Personally, I prefer correctly manufactured and correctly installed polybushes, although use the Kelsport heavy duty original style on the A frame outer joints , in the road car.

[MACCA.GLM]

Interesting the different takes on this subject.

On the first posting with the problems I had ,and rectified on the front suspension I am still not sure on the poly bushes.I recently replaced all the rears and had a bit of a job to get the bushes of the A frames ( small ones) between the gaps of the alloy hub casting.I have heard of people making the gap bigger to get them in.Not a good Idear in my view. I eventually got them in and they seem ok but if I can get the OE bushes of good quality I think I will go back to them when I think necessary .With the proper tools to push them out in I think its the best way.If anyone can recommend a good supplier of these let me know as the the quality of the rubber and bonding is debatable these days and not sure of the quality from the normal lotus suppliers.

The other alternative is to make your own out of a nylon based product and turn them on a lathe. Thoughts on that would be appreciated.


The car handles well with the polys ,and I only changed because the car had old OE bushes when I bought it 10 months ago ,and on inspection these did needed to be changed.

G

[l10tus]

Poly bushes don't give the ride that was designed
People complain of clatter over pot holes and a noisy bumpy ride. They are just not up to it.
People only use them to be swish and think they are up-to date.
The original ones shouldn't be tightened up with the wishbone bolts untill the car is standing on all four legs with wishbones parallel to the floor.

Once all the normal weight is on the car (even an allowance for the driver and passenger) - then it is time to tighten the wishbone nuts and bolts - all as per the workshop manual.
The metalastic joints offer some designed turning resistance to the wishbone movements and assist with suspension stiffness and damping performance.
Poly bushes allow the inner stainless steel bush to become a bearing, allowing the wishbones to swing up and down too easily.

Horrible ride with poly bushes compared with a new taught metalastic set up.

Any use of poly bushes is done in ignorance of the correct designed set up.

Poly bushes are very easy to install, that's why people opt for them, but as you know the saying goes "you don't get something for nothing". It's worth the pain of doing the job properly, fitting metalastic bushes are originally intended.

When you find out remember who told you!

[miked]

I would not consider myself ignorant. But who knows
I am fully aware of what they are meant to be as I guess Mr Miller was.
I would say that there is a belief that all poly bushes are of the hard type and knock your teeth out. This is not the case. Certain grades may well be but not the type I have used. No problem with ride quality.
As regards ease of flitting, on the contrary, the old standard ones have to be pressed out anyway. Then new ones can be pressed in. They are very forgiving for chassis and A frame inaccuracies. I wrote "war and peace" on here years ago about having to true up Spyder wishbones bones dimensional inaccuracies. Spent hours filing and measuring the rear chassis mounts and A frames. The original Lotus bones are spot on provided they are not bent out of alignment. If you check the clearance either side of the rear inner bone bushes you will likely find the clearance either side will not be equal. Not centred.
That's why folk end up with difficulty pushing in A frames. Didn't someone on here loose the end of his finger.
To fit poly bushes required a lot of checking of alignment and avoidance of stresses. Even reaming the bone inner bores so the bushes don't migrate outward and bear heavily on the washers. Again some of the after market bones and A frame bush bores are 20 odd thou smaller. Plus the bush tubes are longer. This is why people have problems with them. I have always dummy built without springs to the rear to check for free movement. Built the front without the shock and spring. Check nice free movement. So in my humble opinion I would ram some of the older bushes out and in with my press in a crack. Also shove them home by distoring the bush position.
In the distant past I have purchased rubber bushes and had to look through the suppliers box to find a group were the crush tubes are concentric with the outer tube.
For what it is worth I think the final result of putting in the effort is worth it.
Happy to allow the dampers to do the damping without assistance from twisting rubber

[bitsobrits]

Phillip,

You carry on as if all poly bushes are the same, which is simply not true. Making blanket statements such as you are doing simply shows your lack of knowledge on this subject. There are many fine and correctly designed poly bushes available for Elans that do not cause a harsh ride or "clatter over potholes". I've have correctly designed quality polyurethane bushes on my two Elans (the S1 since 1993!), my Jaguar E, and my Ferrari 308. Silent, compliant, and long lasting in all cases.

You simply don't know what you are talking about.

[phil1800]

I don‘t understand the discussion that is going on here: My understanding is that good quality rubber bushes are no longer available, thus you should move to poly bushes.Is that statement true? If yes, what are the recommend poly bushes for street use? If good quality rubber ones are still available, where do I get them?

Thank you!

Philipp
67 S3 dhc

[2cams70]

I know of no OEMS that have ever used poly bushes in their suspensions in anything other than stabilizer bar link applications

[l10tus]

Well said 2 cams 70, well said.

[SENC]

I was not able to find good quality metalastic bushes so converted to poly as some of the others have. I did not note any particular change in suspension feel (other than the improvement from replacing a couple bushes that had failed). I would have preferred metalastic just for ease of reassembly (press them back in just like you press them out), and if anyone can point to a consistent quality source I may go back at next change.

I'll see if I can find my notes on which poly bushes I used... but it has been 4-5 years, I think, so may not be useful even if I find it.

[rgh0]

I know of no OEMS that have ever used poly bushes in their suspensions in anything other than stabilizer bar link applications

OEMS do things to make assembly line production easy. Poly bushes and suspension arms are not as easy to assemble and suspension arms with press in bushes

[2cams70]

I know of no OEMS that have ever used poly bushes in their suspensions in anything other than stabilizer bar link applications

OEMS do things to make assembly line production easy. Poly bushes and suspension arms are not as easy to assemble and suspension arms with press in bushes

I've actually had experience in automotive OEM and I can assure you if poly bushes performed better than metallastic bushes they would indeed be used. For example these days having one ignition coil per spark plug is the norm for performance reasons despite the cost implications of having to use multiple coils instead of just one.

Automotive evolution typically involves using better technology on the high end models where the profit margin is greater first. If it's proven to be better it then filters down to lower end models as the cost of that technology reduces over time. I don't think you'd find poly bushes used in the suspension on a Bentley - except perhaps on the stabiliser bar links where bush friction isn't an issue. Metallastic bushes are obviously more costly and difficult to make than poly bushes which is why the aftermarket hardly ever supplies them!

[rgh0]

I know of no OEMS that have ever used poly bushes in their suspensions in anything other than stabilizer bar link applications

OEMS do things to make assembly line production easy. Poly bushes and suspension arms are not as easy to assemble and suspension arms with press in bushes

I've actually had experience in automotive OEM and I can assure you if poly bushes performed better than metallastic bushes they would indeed be used. For example these days having one ignition coil per spark plug is the norm for performance reasons despite the cost implications of having to use multiple coils instead of just one.

Automotive evolution typically involves using better technology on the high end models where the profit margin is greater first. If it's proven to be better it then filters down to lower end models as the cost of that technology reduces over time. I don't think you'd find poly bushes used in the suspension on a Bentley - except perhaps on the stabiliser bar links where bush friction isn't an issue. Metallastic bushes are obviously more costly and difficult to make than poly bushes which is why the aftermarket hardly ever supplies them!

I simply disagree