Bolt on Rack and pinion

[robnolimit]

Originally Posted by crakarjax

Ah right I was thinking about the No Limit kit, which has clearance issues if the crossmember is pancaked or set up into the frame iirc.

This one doesn't have that issue since it's located to the frame, but it looks like it hangs as low as the crossmember such that pancaking the x-member or setting it up into the frame wouldn't gain any clearance, but it's hard to tell give n the angles in the pics. Can anyone confirm that?

A note about steering geometry. For rack conversions (or any steering/crossmember mods) it is important to understand the geometry relationship between the inner tie rod ends (steering pivot) and the lower control arm mount (LCA pivot) is very important. So, if you raise the crossmember (which is raising the LCA pivot) then you must raise the steering by the same amount. - Or it will have drastic bump-steer. If you 'pancake' or raise the crossmember with the stock box, you can raise the box and idler arm the same amount, or you can leave them in place and fab a custom center link with raise mounts for the inner tie rod ends. But, the relationships need to stay in place.

[crakarjax]

Originally Posted by robnolimit

A note about steering geometry. For rack conversions (or any steering/crossmember mods) it is important to understand the geometry relationship between the inner tie rod ends (steering pivot) and the lower control arm mount (LCA pivot) is very important. So, if you raise the crossmember (which is raising the LCA pivot) then you must raise the steering by the same amount. - Or it will have drastic bump-steer. If you 'pancake' or raise the crossmember with the stock box, you can raise the box and idler arm the same amount, or you can leave them in place and fab a custom center link with raise mounts for the inner tie rod ends. But, the relationships need to stay in place.

Rob would your kit work with a pancaked crossmember? I haven't done a ton of research yet but it seems like pancaking is a good alternative to setting the x-member into the framerails because raising the whole crossmember might necessitate raising the engine also for clearance...

Can you explain why the relationship between the inner tie rod end and LCA pivot is important rather than between the inner tie rod end and steering knuckle? I was thinking that a pancake could be offset by flipping the outer tie mount to the bottom of the knuckle.

[crakarjax]

I found this drawing that seems to explain what you were referring to. It seems though that eliminating bumpsteer really depends greatly on the vehicle's spring compression at ride height since that affect the IC. The more I learn about suspension geometry the more it seems like you really need a fully custom solution if you aren't stock!

[robnolimit]

good drawing. If it were in Auto-Cad, and you could move the suspension up/down, you would see that there is very little bump-steer in a properly designed system, and it should stay on point through the entire travel range.

Pancake vs. raising the crossmember - The suspension components don't know the difference (if done correctly) Everything moves up the same amount. Lets say you raise or pancake the crossmember 1 1/2", then you must raise the inner tie rod end to match, 1 1/2". There are a couple of ways to do this, as I mentioned earlier, but the steering needs to stay in the same relationship to the suspension.

[FreeRangeChicken]

I'm looking at the Unisteer for my 67 C10. I'm swapping in an LS2+4L65E. Unisteer is telling me there are oil pan clearance problems with LS installs. Anyone have any experience with this?

Specifically, Unisteer is saying the hard lines on the rack have a clearance problem with the oil pan. They said JEGs has a steel oil pan, and that using that and raising the motor 1/2" will clear the pan. I just bought a new aluminum pan for the motor, and the pan is supposed to be a structural part of the LS motors, so I'm not really keen on swapping to a sheet metal pan.

I think I spy an LS pan in Rob's install photo.

Just wondering if others here have experience using the Unisteer kit with an LS swap. I'm currently using single piece adapter plates and the stock SBC perches and motor mounts.

Thanks.

[indianpride77]

Originally Posted by robnolimit

Just to be clear, our No Limit C10 rack and pinion will work with stock lower arms on 63-72 trucks. For the 73-87, tubular lowers are required. We recomend Porterbuilt Forward Lower arms. The problem is with the huge bushing and stamped arm on the stocker, there is no room for the rack. Swapping to the tubular arm also gives you a bit more ground clearance.

.


So rob will this work on a 76 with cupped lower control arms and a pancaked crossmember?
Posted via Mobile Device

[aggie91]

Originally Posted by indianpride77

.


So rob will this work on a 76 with cupped lower control arms and a pancaked crossmember?
Posted via Mobile Device

Only if the lower arms have been changed...the '76 lower arm bushing is still the issue.

[cjohnson6772]

I know this is a long shot, but is the OP still around and able to give feedback on the POL R&P kit for long term usage?