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I have been getting a lot of questions lately from customers in regard to rear upper and lower links so I figured I would try to answer them in a thread. The main question is,” What are the benefits of aftermarket links for my FJ”
The benefits of aftermarket links are basically two fold. The first benefit is strength. The stock links, both lower and upper are anemic at best and in my opinion under built. Anyone that has wheeled their FJ in the rocks has either bent a lower link themselves or seen it done by others.
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The worst case of this is that the link gets a kink in it and then tears on the link leaving the vehicle without a major rear axle location component. The tube used on the OEM links is 1.25” in diameter and has less than a .120” wall thickness. That is less than 1/8”. Our replacement links us 1.5” X .250” wall DOM tube on the standard links and 1.75” X .250” DOM on the adjustable links. The standard links can also be ordered with the 1.75 DOM tube as well.
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Bending can also be an issue with upper links. These links use aprox. ½” tube. The photo shows a link from my FJ that was “stress” bent. The only explanation I can give is that the suspension moved farther than the link could handle and it bent. It was bent down. Our replacement links use 1.25” X .125 wall DOM tube, far stronger than the tube it replaces.
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The second benefit of aftermarket links is the use of better end links. In our case we use a Johnny Joint on one end that provides 30 degrees of side movement and a high quality, graphite impregnated urethane joint on the other end. What the combination of these joints does is allow the rear suspension to move freely.
I am often asked if our links provide more travel of the rear axle. The answer is no. If pushed hard enough the stock links will max out the available travel of the rear axle. What the Johnny Joints and urethane rod ends do is allow the axle to move much easier. You will notice this most in the area of droop, where the old links held the axle back, the new links allow it to get to full droop without the links holding it back.
The problem with the OEM links is the rubber bushing used, both upper and lower. The way this bushing works is at the heart of the problem. The inner sleeve, where the bolt goes through the bushing, gets locked to the axle and the frame when the mounting bolt is tightened down. The sleeve can not move. The rubber bushing is fused to this sleeve and also to the outer sleeve. The outer sleeve is then pressed into the rod end.
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What happens is that when the link rotates on the bushing the rubber twists and creates tension. If you were to remove the 4 bolts holding the upper and lower links to the axle and remove the panhard bar and remove the axle from the rig this would leave all 4 links hanging in space from their frame side mounts. If you were to pull down on any of these links and release it, it would spring back to it’s original position.
The Johnny Joints and urethane joints both swivel freely and would simply rotate down until something stopped their travel. The Jonny Joint also allows 30 degrees of movement side to side, or in “twist”. This is more movement than the stock geometry of the FJ will allow, thus only one Johnny joint used.
One more point. For those of you that have added a lift to your rig and have the stock links in place. Go out and loosen the mounting bolts to all 4 of your links and then tighten them back up. This will release the tension stored in the rubber bushing that was put in when you installed the lift. What happens is that when you lift the truck you change the ride position of the links, they swivel down. But the links are still locked in and this twists the rubber in the bushing causing the bushing to be under stress while just sitting there.
I hope that this helps answer some of the questions I have been hearing.
The benefits of aftermarket links are basically two fold. The first benefit is strength. The stock links, both lower and upper are anemic at best and in my opinion under built. Anyone that has wheeled their FJ in the rocks has either bent a lower link themselves or seen it done by others.
The worst case of this is that the link gets a kink in it and then tears on the link leaving the vehicle without a major rear axle location component. The tube used on the OEM links is 1.25” in diameter and has less than a .120” wall thickness. That is less than 1/8”. Our replacement links us 1.5” X .250” wall DOM tube on the standard links and 1.75” X .250” DOM on the adjustable links. The standard links can also be ordered with the 1.75 DOM tube as well.
Bending can also be an issue with upper links. These links use aprox. ½” tube. The photo shows a link from my FJ that was “stress” bent. The only explanation I can give is that the suspension moved farther than the link could handle and it bent. It was bent down. Our replacement links use 1.25” X .125 wall DOM tube, far stronger than the tube it replaces.
The second benefit of aftermarket links is the use of better end links. In our case we use a Johnny Joint on one end that provides 30 degrees of side movement and a high quality, graphite impregnated urethane joint on the other end. What the combination of these joints does is allow the rear suspension to move freely.
I am often asked if our links provide more travel of the rear axle. The answer is no. If pushed hard enough the stock links will max out the available travel of the rear axle. What the Johnny Joints and urethane rod ends do is allow the axle to move much easier. You will notice this most in the area of droop, where the old links held the axle back, the new links allow it to get to full droop without the links holding it back.
The problem with the OEM links is the rubber bushing used, both upper and lower. The way this bushing works is at the heart of the problem. The inner sleeve, where the bolt goes through the bushing, gets locked to the axle and the frame when the mounting bolt is tightened down. The sleeve can not move. The rubber bushing is fused to this sleeve and also to the outer sleeve. The outer sleeve is then pressed into the rod end.
What happens is that when the link rotates on the bushing the rubber twists and creates tension. If you were to remove the 4 bolts holding the upper and lower links to the axle and remove the panhard bar and remove the axle from the rig this would leave all 4 links hanging in space from their frame side mounts. If you were to pull down on any of these links and release it, it would spring back to it’s original position.
The Johnny Joints and urethane joints both swivel freely and would simply rotate down until something stopped their travel. The Jonny Joint also allows 30 degrees of movement side to side, or in “twist”. This is more movement than the stock geometry of the FJ will allow, thus only one Johnny joint used.
One more point. For those of you that have added a lift to your rig and have the stock links in place. Go out and loosen the mounting bolts to all 4 of your links and then tighten them back up. This will release the tension stored in the rubber bushing that was put in when you installed the lift. What happens is that when you lift the truck you change the ride position of the links, they swivel down. But the links are still locked in and this twists the rubber in the bushing causing the bushing to be under stress while just sitting there.
I hope that this helps answer some of the questions I have been hearing.
