Whitey
Tweet
Hey everyone,
After putting in some new suspension, I was interested in getting my swaybar back to a more level position at ride height by using extended swaybar links.
I’m trying out the Roadsafe links, which have a rose/heim joint, with a greasable zerk.
There wasn’t very much information about how much longer than factory the extended links can be, so I started out with the swaybar parallel to the lower trailing arm at ride height, which gave me a link about 47mm longer than factory.
After cross flexing on my Stanfred ramps, I could quickly see that I could bind the bottom of the swaybar ring eye on the top of the lower trailing arm (LCA) with the top of the rear axle still a long way from touching the bumpstop, around 45mm.
I decided to cut them down to 40mm longer, and at maximum articulation with cross flexing on my ramps, there was a small LCA-ring eye gap of around 11mm, and I could rock and pull the Prado down and get it within a whisker of binding on the arm, with still around 45mm of bump travel left. 40mm longer links will definitely bind on the trailing arm.
After reading AJ120’s thread about extending his swaybar links, I decided to chop them down to 30mm longer, and as my cross flex on the ramps wasn’t enough articulation, I found a big rock to drive up on, and got the axle to bumpstop gap down to around 16mm, and I could see a gap around 10mm between the trailing arm and the swaybar ring eye.
I still wasn’t sure if the 30mm longer link could bind on the trailing arm at full flex, so after a few more pm’s with Andrew, he cunningly pointed out the leverage nature of the trailing arm, and that we should expect the gap at the ring eye to close less than the gap at the bumpstop.
So back on the ramps and cross flexing, and I shuffled the Prado up and down and got about 5 data points, which with the ride height data was enough to plot the leverage relationship, shown below;
It turns out the leverage ratio between the two measuring points is about 2.64:1. The swaybar link will touch the trailing arm around 242mm from the front trailing arm bush centre.
The plot shows that at full articulation, there will be about a 3.5mm gap between the swaybar ring eye and the trailing arm.
With the nature of the construction of the rear bumpstops, the outer section is hollowed out, and as you can see from the plot, all it takes is for about 7.5mm of compression on the bumpstop before the swaybar link will bind on the lower trailing arm.
As such, it appears that 30mm longer links will definitely bind if the Prado is fully flexed out and rocks onto the bumpstop on the compressed side.
I would say we are right at the limit of the extended swaybar link geometry at 30mm longer than factory links. It really is a game of mere mm’s with no safety margin.
I might cut a few more mm off my links, as I don’t want to space my bumpstops down. I’ll probably also run some offset lower trailing arms in the future.
I’d also like to add that running airbags even with minimal pressure of 5-10psi will affect the flex in the rear, and that at high pressure it would be unlikely you will bind the 30mm longer link.
Best
Mark
After putting in some new suspension, I was interested in getting my swaybar back to a more level position at ride height by using extended swaybar links.
I’m trying out the Roadsafe links, which have a rose/heim joint, with a greasable zerk.
There wasn’t very much information about how much longer than factory the extended links can be, so I started out with the swaybar parallel to the lower trailing arm at ride height, which gave me a link about 47mm longer than factory.
After cross flexing on my Stanfred ramps, I could quickly see that I could bind the bottom of the swaybar ring eye on the top of the lower trailing arm (LCA) with the top of the rear axle still a long way from touching the bumpstop, around 45mm.
I decided to cut them down to 40mm longer, and at maximum articulation with cross flexing on my ramps, there was a small LCA-ring eye gap of around 11mm, and I could rock and pull the Prado down and get it within a whisker of binding on the arm, with still around 45mm of bump travel left. 40mm longer links will definitely bind on the trailing arm.
After reading AJ120’s thread about extending his swaybar links, I decided to chop them down to 30mm longer, and as my cross flex on the ramps wasn’t enough articulation, I found a big rock to drive up on, and got the axle to bumpstop gap down to around 16mm, and I could see a gap around 10mm between the trailing arm and the swaybar ring eye.
I still wasn’t sure if the 30mm longer link could bind on the trailing arm at full flex, so after a few more pm’s with Andrew, he cunningly pointed out the leverage nature of the trailing arm, and that we should expect the gap at the ring eye to close less than the gap at the bumpstop.
So back on the ramps and cross flexing, and I shuffled the Prado up and down and got about 5 data points, which with the ride height data was enough to plot the leverage relationship, shown below;
It turns out the leverage ratio between the two measuring points is about 2.64:1. The swaybar link will touch the trailing arm around 242mm from the front trailing arm bush centre.
The plot shows that at full articulation, there will be about a 3.5mm gap between the swaybar ring eye and the trailing arm.
With the nature of the construction of the rear bumpstops, the outer section is hollowed out, and as you can see from the plot, all it takes is for about 7.5mm of compression on the bumpstop before the swaybar link will bind on the lower trailing arm.
As such, it appears that 30mm longer links will definitely bind if the Prado is fully flexed out and rocks onto the bumpstop on the compressed side.
I would say we are right at the limit of the extended swaybar link geometry at 30mm longer than factory links. It really is a game of mere mm’s with no safety margin.
I might cut a few more mm off my links, as I don’t want to space my bumpstops down. I’ll probably also run some offset lower trailing arms in the future.
I’d also like to add that running airbags even with minimal pressure of 5-10psi will affect the flex in the rear, and that at high pressure it would be unlikely you will bind the 30mm longer link.
Best
Mark
Comment