Outer Limits 4x4 Board

After almost 9000k's in 2 1/2 weeks, my 290K swb GQ is in desperate need of new bushes at the front (got steering alignment when i got back and they showed me)

My question is exactly what the topic says.... Original or Aftermarket?

What are the different materials and the pro's and con's of each in your opinion/experiences (hopefully leaning towards the experience option)?

Anyone got some rough prices? i know that original nissan are about $50 each (just under, $47 and something cents i think i was quoted)

thanks

marin

I use original ones because i found the other type Nothane dont flex as much an tear an dont last as long as original ones.

Go with the original rubber bushes. The factory rubber bush is superior through it's design and material.

Rubber bushes are not available as caster correction bushes though, so if you need caster correction you will be stuck with urethane, ARB seem to have the best design.

The bush goes through several motions to work properly. First is crushing - as the front diff articulates, the radius arms move in an opposite arc to each other (pivoting from the frame) and the diff in effect becomes a huge torsion bar with opposing rotational forces from each arm. The component that does the work here is the bush, crushing as the diff cycles through articulation. Through the design on the rubber bush, there is enough void space for the rubber to crush, expand into the void and allow articulation. The urethane bush totally fills the area where the bush sits and does not allow this expansion, therefore preventing flex.

The arm will also 'rotate' in the housing (on the axis from the chassis mount), and due to the design of urethane the rotation is prevented because of the design of the bush.

Also the crush tube on most urethane bushes is larger than the rubber ones, less urethane means less material that allows flex.

Rubber.

All good.

That was a sensational reply, thanks very much Area54 exactly the info i was looking for, although i'm thinking Hottiemonster might not like to hear about having reduced articulation cauz of his bushes

marin wrote:That was a sensational reply, thanks very much Area54 exactly the info i was looking for, although i'm thinking Hottiemonster might not like to hear about having reduced articulation cauz of his bushes

grrr.

i would have liked more yesterday ben on that hill where i almost rolled. that was one f@cked up track!

i have used the same aftermarket bushes throughout my whole truck and they seem to work really well they don't inhibit any movement at all, and really absorb alot of punishment. the rear lower links are eating one side of the bush at the chassis end though. I have to have a bit of a think about how to stop this, the rest of the bushes around the truck are still like new...

Area54 wrote:Rubber bushes are not available as caster correction bushes though, so if you need caster correction you will be stuck with urethane, ARB seem to have the best design.

I have rubber castor correction bushes (3° I think) on my GQ. Not sure who's they are but I can probably find out, I believe they were supplied by Arctic Cool Treads in Brisbane.

Wendle wrote:i have used the same aftermarket bushes throughout my whole truck and they seem to work really well they don't inhibit any movement at all, and really absorb alot of punishment. the rear lower links are eating one side of the bush at the chassis end though. I have to have a bit of a think about how to stop this, the rest of the bushes around the truck are still like new...

Easy, go genuine. The mount and link bush tube are acting like a guillotine at flex, the genuine bushes don't have any material where your bush is getting chewed. Contrary to popular beleif, the genuine bushes flex really well - the secret is in their design. They have the voided section which gives them the flex advantage.

nah, they are actually splitting from the inside out, then the flange falls off. the "guilotine effect" is nearly non existant in this spot due to the link being triangulated. in the front end, the "guillotine" can clearly be seen, but it is within what the bush can deal with..
it has me stumped. in the other end of this very link the bushes are stil inl factory fresh condition?

The bush at the diff end does not receive the same amount of torque and rotation travel as the front one does because of the triangulation. the front bush rotates more through the arc of travel, the diff bush doesn't because it doesn't travel the same distance (in rotational terms here) as the front bush on flex, also friction will chew out urethane bushes real quick if they are not regularly lubed. The crush tube is held fast by the bolt, the urethane is then left to absorb the crush load AND maintain a slippery bearing surface - too much to ask from urethane unfortunately. The rubber bush is far superior here as the rubber will flex during rotation, and because the rubber is vulcanised to the steel crush tube there is no friction between surfaces.

Have you ever chewed out a new genuine bush?

Area54 wrote:The bush at the diff end does not receive the same amount of torque and rotation travel as the front one does because of the triangulation. the front bush rotates more through the arc of travel, the diff bush doesn't because it doesn't travel the same distance (in rotational terms here)

I'm just trying to get this bit through my head.
The only reasons I haven't used rubber bushings is that the 690mm width was too wide for some of the mounts, and I was worried about the rubber tearing away from the crush tube with the rotation you have talked about. If that happens with the rubber bush, there is nothing to stop the end of the link binding up against the edge of the mount. I don't think it would be a problem on the rear. but on the front, where the links are quite short, they would need to rotate a hell of a lot without tearing.

Have you thought about boring the centre (of the bolt) to make it greasable, like a shackle bolt? Urethane shackle bushes chew out the same way if they are not regularly lubed, hence the recommendation to fit them with greasable shackles to keep them in top shape. Even though your bushes are not supportin the weight of the car, they are still copping a huge crush load upon accel and hill climbing. A bit of dryness and a bit of grit, an' you got gritty-kitty syndrome with lotsa chafing...

From that pic it looks like it is cracked/chewed right where the crush loading is at it's highest, and the bush has been chewed off by the link as it gets squashed by accel or hill climbing. The links taper out towards the rear diff, away from the chassis line, don't forget that as the passenger side (that's the side the pic is from, right?) goes into full stuff, the diff travels in the arc set by the panhard and moves towards the passenger side as the diff articulates to full stuff on the passenger side. (unless you run upper a frame), but the link will still move up and out toward the frame mount on full stuff.

Area54 wrote:Have you thought about boring the centre (of the bolt) to make it greasable, like a shackle bolt? Urethane shackle bushes chew out the same way if they are not regularly lubed, hence the recommendation to fit them with greasable shackles to keep them in top shape. Even though your bushes are not supportin the weight of the car, they are still copping a huge crush load upon accel and hill climbing. A bit of dryness and a bit of grit, an' you got gritty-kitty syndrome with lotsa chafing...

Wouldn't help much as the grease is between the bush and the crush tube, not the bush and the bolt. The whole thing was only assembled a month or so ago, so there is heaps of grease still active in there. Gritty Kitty ROFL.

Area54 wrote:From that pic it looks like it is cracked/chewed right where the crush loading is at it's highest, and the bush has been chewed off by the link as it gets squashed by accel or hill climbing. The links taper out towards the rear diff, away from the chassis line, don't forget that as the passenger side (that's the side the pic is from, right?) goes into full stuff, the diff travels in the arc set by the panhard and moves towards the passenger side as the diff articulates to full stuff on the passenger side. (unless you run upper a frame), but the link will still move up and out toward the frame mount on full stuff.

I knew something in your maths didn't add up. there is no panhard rod. that is the drivers side lower link, it runs from inside the chassis rail outwards to the axle next to the tyre. The uppers run of the top of the pumpkin to the inside face of the chassis rail.

4 link. was wondering - we both had very different pictures in our heads.

Forgot about the crush tube... grease nipple on the bush tube on the link with a hole through the centre of the urethane to the crush tube.

Perhaps you have crossed the limit to what a urethane bush will tolerate in its travel.

Area54 wrote:Perhaps you have crossed the limit to what a urethane bush will tolerate in its travel.

funny thing is, that when the suspension is cycled some of the other joints look to be deflecting a lot more than this particular one?

At this point, I'd call Mulder & Scully.

wendle, maybe you could try some of the blue poly bushes [fulcrum] as i have had them in for 2 years so far.
The rubber ones tore from rotational forces so i put the poly bushes in as they could rotate on the steel sleeve.
Have to admit the bushes are worn but they flex good now so i wont change them until they get sloppy or break.
maybe your problem is that the bush is not square within the tube and pressure is already on that side of the bush...maybe try turning the arm upside down to see if it still does it ?
shane

Area54 wrote:At this point, I'd call Mulder & Scully.

funny as

well, after pulling the link out and checking everything out, the bushes definately haven't let go due to the twisting moment. they look like they have just loaded up too much under torque compression and spit the dummy. I am thinking that what might have started them tearing is the weld on the end of the link, the diameter of the link itself is the same as the width of the the tube holding the bush, so the weld was compressign the flange a bit on each side. I linished those flat, then spent a fair bit of time sanding the shit out of everything else to make sure there was no other edges to catch up on anything.... See how it goes, I guess??