Rubber Vs. Urethane?

[Longman]

Hi All,

Late last year I replaced a large portion of gear under the front of my VT sedan. I put brand new Brakes (rotors, calipers, pads), Caster bushings, sway bar D rubbers, Z style link pins, struts, springs, bearings, yadda yadda...

Ever since, the link pin nuts have been rattling loose. Every 2 weeks I've had to go in and retighten the nylock nuts. Over the last few days, the noises from the front have been embarrassing, very loud knocks, rattles and vibrations.

So, I get under there today and the urethane bushes on the link pins are gone, top and bottom, completely absent, both sides! Not bad for 10 months use, the originals lasted 10 years!

Obviously I need replacements. Given the success I haven't had with urethane, I was wondering if perhaps I should change back to rubber bushes? or go with a new Nolethane kit. The previous link pins are heavy duty, but not nolethane brand, considerably cheaper options. The caster bushings are nolethane and I've had no problems with those.

I seem to recall someone telling me the philosophy of either "rubber bushings for up/down and urethane for left/right moving parts" or the other way around.

Thanks!

[immortality]

rubber is natural product and degrades over time. urethane is synthetic and doesn't.

if the bushes on the link pins are over tightened they they will fail quickly. try the Noltec bushes. they are slightly softer then the nolathane ones.

back many years ago urethane only came in a single hardness (for automotive use) which just didn't suit all the different types of bushes around the car. these days you can get different hardness bushes so urethane bushes are better suited to all applications.

get some new locknuts too, nyloc nuts aren't fantastic for multiple uses

[Longman]

Cheers, I'll look into the Noltec ones.

[glowworm]

i would not use Nolethane i did once and and they didnt last long i use rubber ever time now dont even have to think about it ..........

[dynoryder]

the link washers were on upside down i see this at work all the time as i work at pedders we sell lots of bushes to other mechanics and they seem not to know how to install our gear they allways calling back up and wasteing our time

urathane in commeys works good on sway bar d bushes and links lower arms need rubber the radius rod bushes in the front are good to use urathane this is how we set cars up

the back (IRS) urathane for cradle bushes inerpivot(toe kit) urathane outer pivot (camber offset) rubber diffbush urathane insert sway bar all urathane

live axle rear rubber lower tralling arms bushes urathne in upper arms if needed for tramp if grany driver rubber is fine sway bar urathane

hope this helps

[dynoryder]

o yea btw strut tops always need replaceing after 100000km they rubber

[Longman]

Thanks for the info. I installed the washers facing away from the bush, ie. the convex side had the nut in it. Is this right? I did it opposite to the way the instructions said.

[dynoryder]

no nut goes in concave side

[Longman]

I ended up with a Nolathane kit. It was the only decent kit I could source without having to order, and I wasn't going to go with Superheap junk.

Thanks all for the input.

[greenfoam]

Rubber, I would have read the original post but the answer to this is allways rubber anyway so I wont

[jazza15]

Yeah i'd have to agree with dynoryder on this one. Urethene for some high stress (would I be right in saying?) applications, while rubber where a bit of give/movement is needed.
Rubber strut tops was where I was leaning towards as i think urethene would be too harsh for the shockers over every day bumps etc.
I'm replacing my cradle soon, and my donor creadle's bushes are split., so will be forking out for the urethene ones as I hear they will reduce axle tramp and generally last longer (I don't ever want to have to replace those ones again!).
Urethene on the rear control arms seems to be a no brainer as if you think about it, the amount of movement that these bushes cop, urethene is the sensible option to keep things in line a bit more, by that I mean not bending and twisting so much at the pivots.
I just recently replaced my control arm bushes (at home after much, much time and frustration) with urethene ones. I think this may have been the wrong option considering that I don't think that they have ever been changed (230,000 + kms) and weren't in that too bad condition. Urethene may have been an overkill that puts un-necessary strain on my suspension system... oh well, too late!

[Tsunamix]

Urethane lasts longer than rubber unless exposed to solvents like acetone. Rubber deforms differently over time, depending on exposure to the atmosphere. Urethane doesnt. In a nutshell, Urethane tends to produce more accurate and consistent results in terms of dynamics, where rubber produces more muted and less accurate responses (which tends towards a softer ride).

The reason your urethane bushes dissappeared is because the curved washers were installed the wrong way around. The curved face mounts facing AWAY from the bush )||(, not (||) , not facing into the bush. That will also stop your nylok nuts coming loose as the loading remains constant.

[Not_An_Abba_Fan]

^^^^ Agreed.

But the substance referred to is polyurethane, not urethane.

Rule of thumb for a comfortable ride is to use rubber on any bush attached to the body of the vehicle and polyurethane on outboard components.

If comfort and harshness aren't a factor you can use polyurethane on everything.

The advantages of polyurethane are that components move less so the handling of the car is more precise and direct. IMO, totally unnecessary in a road car and overkill.

[dynoryder]

on wrx's and vw golf's we use polyurathane for the radius bushes they are part of the lower arm whiteline in fact makes these in offset to give more castor and anti lift which stops dive

in fact most types of radius bushes (like 98%) we use polyurathane because it controls lateral movment

[vxcalais_01]

i would not use Nolethane i did once and and they didnt last long i use rubber ever time now dont even have to think about it ..........

dratz. THey wont work either. You need to go a double ball joint design. I have chewed through a couple. Fulcrum has a double ball joint one, same guys who supply super pro, and Nolathane now have a previosu whiteline design, very heavy duty, it is the best they have come up with. The problem is the rubbers, be it rubber or poly-urethane. Causes stress on the rod itself and anywhere else it touches. The ball joint system allows it to flex.

42708X or 42997AX - Part number to get. If yours is direct up and down, ask for the heavy duty without the bend on the bottom.

http://www.nolathane.com.au/bulletin...Bar%20Link.pdf

Can you see the silver ones with black ball joints, these are the ones you need, my car bent the heavy duty red ones prior to me fitting these type. Super pro have one same design, thinner bar. These were made by Whiteline before i think before Redranger bought them.

[dynoryder]

dratz. THey wont work either. You need to go a double ball joint design. I have chewed through a couple. Fulcrum has a double ball joint one, same guys who supply super pro, and Nolathane now have a previosu whiteline design, very heavy duty, it is the best they have come up with. The problem is the rubbers, be it rubber or poly-urethane. Causes stress on the rod itself and anywhere else it touches. The ball joint system allows it to flex.

42708X or 42997AX - Part number to get. If yours is direct up and down, ask for the heavy duty without the bend on the bottom.

http://www.nolathane.com.au/bulletin...Bar%20Link.pdf

Can you see the silver ones with black ball joints, these are the ones you need, my car bent the heavy duty red ones prior to me fitting these type. Super pro have one same design, thinner bar. These were made by Whiteline before i think before Redranger bought them.

yes the ball joint system is good this is what vz and ve use whiteline has a good one or you can by vz shocks and use stock ones may be cheaper if you need shocks

but i rearly see the urathane ones wear out only see them stuffed from wrong intsallation