Thread: Nolathane bushes

Urethane does not like heat, and in most applications, requires suitable lubrication ( molybased grease ) Again heat from friction is a no no. Some tropical applications are trouble prone no matter whether there is lubrication or not

As for different hardness rating on the bushes, I would ask to see data. I would be surprised if there is much difference in any of the modern urethane bushes from Oz manufacturers. The US manufacturers like Calmino, tend to use rock hard Urethane. ( read like metal hard )

If the bush has a lubricated centre sleeve it can be tightened with the component in an unloaded position. If the bush is fully moulded with a fixed sleeve, it will need tightening in the normal loaded position.

If you are using urethane in leaf spring bushes, ( or anywhere they are lubricated actually ) even with greasable shackles, keep the Karcher or similar away from them when hosing that mud off. They do too good a job in stripping out that lubricating grease.

If rubber has lasted until now, it is a damn good question as to why you would not use it again.

Originally Posted by ADMIRAL

If rubber has lasted until now, it is a damn good question as to why you would not use it again.

X 2.

Originally Posted by isuzurover

That does not apply to rear trailing arm bushes. There seems to be a lot of these bushes getting around these days which are failing after only a few thousand km.

I presume you mean the front bushes on the rear trailing arms, and that is correct, although it applies to the rear ones. Two thoughts - I have had similar failures with both rubber and urethane bushes - but the current ones, genuine OEM parts, have done around 250,000km and are still good! And secondly, how many of the failures are on lifted suspension?

John

Originally Posted by JDNSW

I presume you mean the front bushes on the rear trailing arms, and that is correct, although it applies to the rear ones. Two thoughts - I have had similar failures with both rubber and urethane bushes - but the current ones, genuine OEM parts, have done around 250,000km and are still good! And secondly, how many of the failures are on lifted suspension?

John

This was on a standard vehicle. Rovacraft told me they have stopped selling that brand of bush due to failures.

Over the last ~10 years I have noticed that rubber products seem to be a lot patchier in quality (remember the firestone tyre issue). A friend who had a rubber products business in Brisbane told me years ago it was due to changes in formulation (for reasons I can't remember now).

Personally, I am changing all bushes to super pro, except for the chassis end of the radius and trailing arms.

I have been using poly bushes on the IIA since 1998 with no problems.

Originally Posted by isuzurover

[snip]
except for the chassis end of the radius and trailing arms.

[snip]

LOL, and they are the ideal situations for poly

I've never liked the idea of rotating poly bushes, but they work very well in compression. Having said that I ended up using them on the chassis end of the A frame and they've worked really well for a number of years now with no apparent wear. (the OE ones flogged out the inner steel sleeve and wore part of the 19mm clevis bolt away and yet the bolt and nut were tight )

The Super Pro radius and lower rear trailing arm bushes use circumferential grooves on one side of the radius arms and both sides of the rear lower trailing arms to increase vertical travel without undue binding yet don't take a compression set that the OE rubber ones tend to do (which leads to bad rear steer)

Originally Posted by rick130

LOL, and they are the ideal situations for poly

I've never liked the idea of rotating poly bushes, but they work very well in compression. Having said that I ended up using them on the chassis end of the A frame and they've worked really well for a number of years now with no apparent wear. (the OE ones flogged out the inner steel sleeve and wore part of the 19mm clevis bolt away and yet the bolt and nut were tight )

The Super Pro radius and lower rear trailing arm bushes use circumferential grooves on one side of the radius arms and both sides of the rear lower trailing arms to increase vertical travel without undue binding yet don't take a compression set that the OE rubber ones tend to do (which leads to bad rear steer)

My decision was based on ease of replacement. The 110 is a tourer, so I am not after maximum articulation.

The current (rubber) trailing and radius arm chassis end bushes have been in for at least 10 years and 100000km (the time I have owned the car). They were still in quite good condition when removed. If the replacements fail prematurely I will be replacing them with poly.

The radius arm diff end bushes were shagged - the inner sleeve fell out of 3 of the 4.

Pressing a poly bush in and out is so much easier than rubber - especially when the rubber bush has rusted in...

I have been running (non-superpro - but also fairly soft) poly bushes in the IIA for 15 years and they have been working very well. The IIA gets heaps of flex for a leafer, and I have only needed to replace 2 bushes in that time.