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Installing poly bushings

PostPosted: Sun Dec 30, 2012 4:30 pm
by collins_dan
I am about to install poly bushings front and back. Just built the tool that Dave suggested for removal of front and planning to post my experience. Also planning to try on rears as well with modification. My question is on the install of the front bushings, which have a lip on each side, do I just try to jam these on? Should I freeze first? Or do I shave off one side? Advice appreciated. Thanks, Dan

Re: Installing poly bushings

PostPosted: Sun Dec 30, 2012 4:52 pm
by kstrutt11
For bushes with a collar both sides I usually soften them in boiling water then push them in followed by the sleeve.

Most poly bushes of thius type are usually split in the centre though.

Re: Installing poly bushings

PostPosted: Sun Dec 30, 2012 5:57 pm
by collins_dan
Thanks. The rear with collars are split in the center, but the front are not. I'll try softening first. Cheers, Dan

Re: Installing poly bushings

PostPosted: Sun Dec 30, 2012 7:02 pm
by stevebroad
Don't forget to lubricate reguarly or you will suffer from premature wear and lots of squeaking.

Why are you fitting polybushes as opposed to new rubber bushes?

Re: Installing poly bushings

PostPosted: Sun Dec 30, 2012 8:43 pm
by collins_dan
Thanks. Will lubricate on assembly. I went with poly for number of reasons, longer life and perceived better performance. Not sure that is a universally held opinion, but I will share my opinion once installed. The rest of the suspension front and back is TTR fast road shocks, springs... and that uses poly for the bump stops. Dan

Re: Installing poly bushings

PostPosted: Mon Dec 31, 2012 10:27 am
by Maulden7
I have driven Elans with both new all rubber & all poly bushes, on the road & on track, & imho poly bushes are only suitable for perfectly smooth track use.

On normal UK roads (whatever they are) the "poly" Elan was noticeably more "nervous" to drive. The overall effect is that the overall handling is simply too rigid, more steering correction needed.

The only place that I use poly bushes is on the anti roll bar fixings ..... for two reasons :-
1. I think that this brings the anti roll bar into operation earlier.
2. Even hard rubber bushes don't seem to last more than two years (but perhaps that's just me?)

I know that there's a lot more to overall handling than this, not least the way in which each individual drives the car, but the fact that TT uses poly bump stops is not really relevant. Has anybody asked Tony as to his views on the poly / rubber debate?

Re: Installing poly bushings

PostPosted: Mon Dec 31, 2012 2:06 pm
by collins_dan
Thanks for your opinion.
Here is Tony's price list
http://www.tonythompsonracing.co.uk/pricelist.pdf
Maybe that will answer your question.
Dan

Re: Installing poly bushings

PostPosted: Mon Dec 31, 2012 3:03 pm
by miked
Dan,

Don't be put of by the hardness business as there are different grades of bushes. There seems to be confusion surrounding them. I dont know how hard TTR ones are. I do know that Autobush are a great buy. No connection.

The blue ones that I have used from Sue Miller and also Autobush are not hard at all. The Sue Miller cotton bobbin front type went in no problem after some hot waters (as Kstrutt11 says). One thing to watch out for is that the inner crush tubes do protrude when the are inserted in the ploy bush. If they do not they will bind and lock up on the sides. There is quite a bit written on here about it (by me). I had to have front bones reamed as the ploy was migrating outwards and binding on the washers at the sides.

I will see if I can find the threads later. Done it! Myself and others also wrote a lot about the fitting of them on the rear "A" frames as I had problems with wishbone accuracy.

elan-f14/polyurethane-bushes-t1146.html?hilit=poly%20bushes

elan-f15/poly-bushes-spyder-bones-t13951.html?hilit=

Mike :D

Re: Installing poly bushings

PostPosted: Mon Dec 31, 2012 4:22 pm
by collins_dan
Thanks for the advice. Front is installed. They went on smooth enough, but when nuts tightened, not a lot of movement. How do I test if they are binding or appropriate?

On the rears, I have a dilemma. While the front clearly needed replacing (inner tubes on bottom sliding out), the rear is less clear cut. Outers are fairly dried, but not sliding out. Inners seems fine. With outers detached, the wishbone swings down with resistance and has a rubbery feel, for lack of a better description. Should they be replaced?

Thanks, Dan

PS. I sourced the bushings through RD Enterprises here in the US, who is the local TTR supplier. They are blue and the lubricant packet was labeled Super Flex.

Re: Installing poly bushings

PostPosted: Mon Dec 31, 2012 4:48 pm
by miked
See link. Superflex are what Sue and the late Mick Miller supplied. Sole supplier at one time as I believe Mick came up with the design.

http://www.mickmillerlotus.com/lotus-parts.html


RE: Fronts being tight, you need to work top and bottom in isolation to know which are stiff. Drop off the vertical link and bits.Then you are just working with 4 bones, if you are not already. You then need to check what I said about the inner crush tubes being slightly proud of the poly ... both sides. Did you clean out the bush tube on each wishbone of any paint or rust etc? If they are not spotless they will make the poly extrude outwards to rub on the washers. I have found that Lotus original bones tend to be bang on and the poly bushes fit fine. On aftermarket bones I found them nearly 20 thou smaller (as I recall) which gave me the sh*ts. Had to take to a machine shop to have reamed. I found this as I had original Lotus top bones and some new aftermarket ones on the bottom. Top moved great when tightened up but the bottom went solid (until they were reamed). I just done a Plus 2 with Autobush with Lotus bones and had no issues.

Re: The rear "A" frames. Different folk will have had different issues here. I had to do my inners as they were soft and gear oil soaked. Are yours dry and in good nick? I also believe the opinion is that there is quite an amount of rubber in these so they give quite a flex (more on a Plus 2). Leave them if they look good! Although I think I would change them personally if doing Poly all around.

I have had issue with the outers tearing and giving lots of for/aft' movement. Not much rubber here. I hate these in the standard that they are now supplied. Don't last like the original quality one did. Sue told me that was why Mick sorted the Poly ones because he was changing them 12 months later for an MOT.

If you go Poly on the rear outer with the Mick Miler one there are instruction for fitting stainless washers and also shaving some alloy off the struts. Some people don't like this.
Due to the thickness of the "top hat" design, it is required to get the strut back in. I have a copy somewhere from Sue with the strut measurement.


Mike :)

Re: Installing poly bushings

PostPosted: Mon Dec 31, 2012 6:00 pm
by collins_dan
Front seem good. Inner tube making contact with washers. Jacked both sides under trunnion with nuts tight and loose, no difference, so stiffness is springs, not bushings binding. I have original lotus bones.

On rear, right are right about not much rubber on outers! Inners are not dry, but appear ok. Need to get a new torque wrench, so will have a think on if I want to tackle just now.

Thanks for the advice, Dan

Re: Installing poly bushings

PostPosted: Mon Dec 31, 2012 6:13 pm
by miked
I was talking about testing a least without springs as I don't think you will know what is happening with them in place.

Mike

Re: Installing poly bushings

PostPosted: Mon Dec 31, 2012 6:25 pm
by collins_dan
I was trying to avoid releasing the lower bones from springs if possible as they are such a pain to reattach (heavy anti-roll bar pushes everything out of alignment), but sounds like I have no choice. Dan

Re: Installing poly bushings

PostPosted: Mon Dec 31, 2012 7:53 pm
by miked
Hi Dan,
up to you but I would not be confident that you have clear movement without trying them full stroke up and down. Just bolting them back to the top ball joint and bottom trunion can make them start to grab. With the best will in the world and good lube you could be sticking. The paint on lip of the bones can even bear on the washer. The old bushes are quite forgiving when it comes to some misalignment. I have spent quite a while debugging these but been rewarded with a decent result

Mike :)

Re: Installing poly bushings

PostPosted: Mon Dec 31, 2012 9:49 pm
by collins_dan
Always easier the second time. All had good movement under correct torque settings, thanks to my new torque wrench. On assembly, I lubricated well and was very careful that the inner tubes aligned with ends of bushings, so I guess it paid off. Next up, taking some measurements of the rear before disassembly to see if shaving the struts will be necessary. Thanks for your help. Dan