lift, castor and spring bind..what if adding more lift?

I have really contemplated my next move suspension wise on my truck. The lift i'm running now is great, but i'm pushing the limits of it now, and i need more

here is my question. Right now i'm running medium sprngs front and rear, with a 1 inch Mr. Gasket spacer up front, bull bar without winch, stock rear bumper and slee's castor plates (stock bushings). I do have a little stink-bug. I went this route because for some reason i was at zero degree castor with just the OME CC bushings.

What i do have now is a little.....well, kind of bad, grrrr no matter which front shaft i run (DC or stock). I also noticed that i was having a little noise from the front when i compressed the springs. Closer look showed that my bump stops were rubbing the inside of the front spring at compression.

Right now i am considering either adding ARB lockers F/r and going to the OME competion 5 inch springs front and 4 inch rear and keeping the stock arms with the plates for right now (or keeping the medium and putting portals under it) By going this high, i will be moving the axle back slightly, right? Will that not cause the bumpstop to rub the inside of the spring even more? Right now i attribute the spring rubbing to the excessive castor i have now (no i have not put it on a rack since the plates have gone in and i know i need to, i will, i will). So i think lifting it higher without extending the arm will cause even more spring bind?

Well, you could buy my Slee 4" fronts and Gen 2 control arms once I go 5" Comp front and 3-link.

OK.

Do you have the DC shaft, or have you just tried one out? If you have one, then going with the 5" Comps you'll probably want (need) the arms to get your caster and/or pinion angle into shape. The spring bind should lessen with more lift as it will also rotate your axle forward and keep the spring straighter, but MAY get worse from the axle being pulled backward.

Talk with Christo on the arm swap idea. You had to grind off part of the front bracket which was then strengthened by his plate. Removing the plate and going to the arms might not be a good idea strength wise.

Have you done anything with the panhards yet? If no then that can add to both the spring/bumpstop problem and the Grrr problem.

If it were me I'd ditch those springs and spacers for Slee's 4" springs all around.

got some fronts

I built a small shim/spacer that tilts the bumpstop rearward slightly. It sits between the coil bucket and bumpstop.

Slee's caster plates with OME medium is most likely a "no man's land" in terms of having good driveshaft angles with any driveshaft style given they should work for around 4"-4.5" of lift with a DC shaft.

You are probably right about the over rotation of the axle (high caster) contributing to the bumpstop hitting the spring.

I think that you may be heading down a "tail wagging the dog" road here. Caster is something to fix based on the lift you need for the tire size you want to run based on the trails you want to run. Going to OME comp springs will probably get you close with caster plates and stock arms, but you don't really know.

You will drop your cash all at once, which may not be appealing, but with Slee's caster plates simply adding the other components of his 4" kit is your best bet. You are going to need panhards with OME comp springs as well as brakelines and new shocks, so the outlay to go up is going to be there no matter what.

You could stay lower with FOR 3", but caster is still an issue if you were that low on OME 2".

So what are you trying to build here? Design first and fix caster second.

How is your castor excessive? Did you add Slee's plates and not return the bushings to stock? Either way, you really need to get it on rack to see where you are, as all the suggestions are going to have less meaning. Having the numbers is going to help you figure an acceptable outcome with everyone's help, otherwise it's a crap shoot.

Rick, the small little tab that is ground off, IMHO is insignificant strength wise. If i remember correctly, Christo also mentioned the same when i asked a while back. You also make a great point about not having an adjustable track bar.

Nay, i want to be able to run 35-37" tires at full stuff. I also plan on mixing up my lift components a bit. I like frankie's kit, i just want to sit a little higher. I figured that since the castor plates were originally intended for the 4inch lift, i will be right in the ballpark.

Just looking at the springs today, and visualizing the axle path as it's lifted made me think it would rub the springs worse, and that is why slee arms are the best solution. BUt, right at this point, the arms are the only component i am trying to not spend $ on.

Nay said:

Slee's caster plates with OME medium is most likely a "no man's land" in terms of having good driveshaft angles with any driveshaft style given they should work for around 4"-4.5" of lift with a DC shaft.

Click to expand...

Actually the height of the lift has little to do with the drive angles at the pinion. So if a DC shaft doesn't work now then raising the height won't help.

Nay said:

Caster is something to fix based on the lift you need for the tire size you want to run based on the trails you want to run.

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I'm not sure what tire size and the trails you run has anything to do with caster. It's the height of the vehicle both front and rear.

landtank said:

Actually the height of the lift has little to do with the drive angles at the pinion. So if a DC shaft doesn't work now then raising the height won't help.

I'm not sure what tire size and the trails you run has anything to do with caster. It's the height of the vehicle both front and rear.

Click to expand...

Huh? Lifting rotates the pinion upward and reduces caster propotionately. These are fixed ratios. "Caster plates" just create a modified bracket to rotate the pinion using stock arms (and they could move the axle forward or backward as well). This is a fixed ratio and it only works at a certain small lift height range, or we wouldn't have a million caster threads on this forum. Given Slee sells these with his 4" lift and a DC shaft, one can assume that the amount of rotation is designed for a 4" lift and DC shaft.

So using that same pinion rotation on a 2.5" lift is going to create a) unequal opposing angles for a regular shaft u-joint shaft or b) rotate the pinion enough that a DC shaft has an angle at the pinion. Either way, you should get vibes, and in this case he does. That is an expected outcome. A bit of axle shift fore or aft could be enough to cause the bumptop/coil contact in conjuction with the over rotation.

More lift will rotate the pinion back up, reducing caster and bringing a DC shaft in line. 4" should be about correct unless Slee is selling a kit with improper alignment. Slee's arms don't do anything that a caster plates do - they simply have an increased bend to get pinion rotation, and they also are a fixed solution that works at a specific lift height. You can't simply say "I am going to buy Slee arms and now my driveline angles will be correct." That only works at specific lift heights.

Slee's arms rotate the pinion down more than the caster plates because the plates are for the 4" lift and the arms for the 6" lift, so this issue isn't going to get better with those arms unless lift goes way up. All I am saying is chose your lift and then fix caster. The more lift you have the more you will need the pinion to point up and the more your coil buckets will rotate around the axle centerline.

Bottom line: you are using an axle adjustment method on a lower lift than it was intended for and that is not a good basis for assessing a taller lift and the adjustments required on said taller lift. Either go to the 4" kit using brackets and stock arms, or start from scratch, but don't worry about how it works on OME medium because it doesn't.

Nay said:

Huh?

Click to expand...

Go back and read what I wrote.

Just raising the vehicle with the axle bolted in place as it is now you will not see a big difference in the pinion angle. All the movement happens at the rear joint.

This is do to the location of the arm's pivot point and the t-case flange.

I'm sure at some level there is a difference but if he's got vibs now with a DC shaft raising the vehicle an inch or so won't make a difference. He needs to address that but changing the axle's position on the arms and not the height.

Check this post to see what other people have done and what is or isn't working for them. This is why that post was started.
https://forum.ih8mud.com/showthread.php?t=135405

Well, i got a caster sweep today. Here are the measurements. It explains why my spring is rubbing on the bumpstop.

And, wagoner, based on the thread you linked, the lead in Rcaster explains why i have a pull to the right also.

That's some serious amounts of caster. I'm curious just how high you are now. It almost looks like Slee's plates are over kill.

landtank said:

That's some serious amounts of caster. I'm curious just how high you are now. It almost looks like Slee's plates are over kill.

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Rick, you are probably right about overkill. I went from zero to that with the addition of plates and stock bushings. But i must add that since that measurement i have added an ARB bull bar, so the front is squished a little more than the time when the sweep was taken.

I will try to pull a measurement this evening when i get home of wheel to fender. It may also attribute to my powersteering groaning. With that much caster and my camber at zero, my big tires are tough to turn.

I guess the only fix for me is to put the DC shaft in and lift it up to 4 inches

landtank said:

That's some serious amounts of caster. I'm curious just how high you are now. It almost looks like Slee's plates are over kill.

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With that amount of lift they are overkill for sure, but I ran them on my 97 with J prings up front and got similar caster results. The truck drove great down the road though. With that much caster it really went straight.

You should have about .25 degree lead on the right to go down the road straight.

concretejungle said:

Well, i got a caster sweep today. Here are the measurements. It explains why my spring is rubbing on the bumpstop.

And, wagoner, based on the thread you linked, the lead in Rcaster explains why i have a pull to the right also.

Click to expand...

So you are saying you were @ 0* with OME bushings and now ~6* with the plates and OEM bushings? I wonder if it would be possible to reinstall your OME bushings in a way to actually reduce the castor a little? This could straighten out your coils a bit.

Montana Cruiser said:

So you are saying you were @ 0* with OME bushings and now ~6* with the plates and OEM bushings? I wonder if it would be possible to reinstall your OME bushings in a way to actually reduce the castor a little? This could straighten out your coils a bit.

Click to expand...

Yes, that is correct.

I thought about that. Honestly, i think i'm just going to put 4inch springs in in a few months. I have all the components needed except adjustable panhard and rear uppers.