Need opinions on driveability issues with 80

[LCAdvocate]

If anyone can help with this it would be greatly appreciated. I just want to try and get a handle on it myself before I take it to Slee for the fix. Here is the problem: the damn thing is squirrelly while driving. It has a 4" old man lift on the front, 3" on the rear, new spherical and adjustable panhards and rear upper controls, upgraded tie and relay rods, sway drop brackets, etc, etc all from Slee or man a fre. It has the Slee caster correction brackets on the front controls that supposedly correct for 4-5 inches of lift, but its obviously too much or not enough. I had the Man a Fre drop brackets on it before and they worked well, but that was before I switched out all of the rods - I removed those and went we the Slees because they hung down to far. I have not had it aligned yet but that should not cause it to be squirrelly. Any ideas? Thanks,

 

[jeepocabra]

Hmmm have you checked your wheel bering pre load recently?

Sounds like too little caster to me...

 

[Pinetop Cruiser]

I would vote for not enough caster angle. When I was removing an OME lift from one of my vehicles I drove it with the ome correction bushings but stock height and it actually felt pretty nice being overcorrected..a little heavier on the steering wheel, but tracked really nicely.
Good luck and post up when you find the solution.

 

[nakman]

OME 4"... So J's? J's plus spacers?

edit: x2 on wheel bearings, or even something else that's just loose like old trunion bearings. Is it squirrely just on the highway? Only while braking? or all the time? need more info...

 

[e rock]

If you can install all of that (or even understand what it means), then you can pull a tire off and put an anlge finder on the knuckle to figure out what your caster angle is.

And while you're doing that, check the bearings

 

[sleeoffroad]

If you can install all of that (or even understand what it means), then you can pull a tire off and put an anlge finder on the knuckle to figure out what your caster angle is.

Sorry, it is not that simple to measure caster. It will show you if you are on the positive on negative side, but the numbers are not comparable to numbers that you get from an alignment rack.

Also, do you know it is 4" of lift, or a 4" spring that might have yielded more lift due to not enough load? Getting a caster sweep done should be the first step to see what your alignment numbers are.

 

[Scotty]

I just did a full axle rebuild on the front end. That included a full knuckle rebuild on both sides. New trunion bearings, and repacking of wheel bearings and adjustment. Its not them. The problem was both before and after the knuckle rebuild. This is an issue with caster IMO.

Christo, if you don't mind, give me a call today. I have this 80 at my shop still, and would like to pick your brain on it. 970-420-4198.

FWIW, the 80 has an ARB front bumper, and rear 4x4labs tire carrier, on the heavy OME coils. I can throw a digital angle finder on stuff with you on the phone.

Here is a pic of Jay's 80:

The rig is very darty and feels like it is swimming down the road.
It nothing like death wobble though. All components are tight, it just feels like it needs either more caster or less. I haven't even dove into adjusting the front end, but may build some brackets just to test them to see if it changes anything. Jay mentioned that when the kit was initially installed without any correction it handled similar to how it does now. However, with the MAF drop brackets it did much better. That leads me to believe that its a lack of caster doing it.

Jay is going to bring the rig up to you, but I am trying to get it safely drivable for that. Anyway, if you can call me I would appreciate it. As would Jay.

Scotty

 

[Nay]

Caster should be fine with Slee plates and a 4" lift. That's not the rabbit I would be chasing given this setup is virtually the same as tons of other people here. With Slee plates if anything caster is on the high end for that lift, which might result in more steering effort, but not a darty steering feel.

I was hunting demons for a few months that sound pretty close to this. I did have a bad TRE, and fixing that helped a lot, but it didn't clear the issue completely. The one front end bushing that does not get changed in any upgrade is the frame end bushing on the front radius arms. Those are 12+ years old and that single bushing stabilizes the entire front end. If those bushings are worn, the rig is going to be squirrely.

I just replaced those frame end bushings before a 1,200 mile Moab trip. Unbelievable difference - I probably have less caster than this rig as I am using an OME bushing to reduce caster (raise pinion) for DC shaft alignment on my lift in the rear mount on the axle end in conjunction with LT caster plates.

I was pretty convinced I needed at least a driver's side bearing recheck on the front end, and it is rock solid on 37's now.

May be worth replacing since you appear to have replaced everything else. I can tell how bad mine were based on how the rig handles hitting expansion joints around curves on the highway at speed. Night and day.

Oh, one other thing: I think the wide Toyos track terribly. I went from 315/75 Toyos to 37x12.5 trxus and you'd think I just put high performance road tires on it. As my wife told me driving back from Moab in her first drive with the new tires "It's driving like a dream at high speeds". The tire change made a bigger difference than even fixing a totally fragged TRE.

So if everything else checks out, and those frame bushings check out, I would look at the tires. I know a lot of people love them, but I thought they flat out sucked as a road tire except for roundness. I was going to groove mine if I kept them for this reason, because if you have anything going on with the front end at all, those tires seem to call it out in the worst way. Seems to be a "YMMV" thing.

 

[LCAdvocate]

More info and answers to questions

Thanks for the help guys. To answer some of the previous questions: it is squirrely mostly at higher speeds, but not while braking. It has the heavy ome on the front/rear with arb and winch on the front and bumper with tire and ladder on rear. The front has the 30mm spacer to level out the stance and add a little lift. It did drive well with the MAF drops but it was still a little light feeling on the front. That was without the tires and the new rods and arms.

I do occasionally hear a slight banging, clanking sound underneath that might possibly be the control arms worn bushings. I have chased this one for about a month and found nothing loose, but I never really thought of the control arms. I really only hear that noise when I hit those sharp little bumps and variations in the road.

Scott thanks for your help on this.

 

[jasonmt]

The one front end bushing that does not get changed in any upgrade is the frame end bushing on the front radius arms.

Are you sure about that?

 

[Nay]

Ok, doesn't typically get changed

 

[retrofive]

Are you sure about that?

thats shiny

 

[CJF]

I have not had it aligned yet but that should not cause it to be squirrelly.

 

[landtank]

what is the hub center/fender flare measurement?

 

[LCAdvocate]

I don't know the hub/fender measurement, but I will find out. I get the rig back tomorrow and I will post the #'s. I talked to someone that thinks the heavy OME lift and 30mm spacer (only in the front) has resulted in more than 3.5-4" of lift. I don't see how that has happened since the maximum lift for the heavy is 2.5-3" not counting the spacer, especially since I have nearly two hundred pounds of weight on the front and nearly 300 on the rear.

 

[LCAdvocate]

Hub center fender measurement

24.25 rear and 24.75 front. This is a rough measurement but within +/- 1/4".

what is the hub center/fender flare measurement?

 

[CJF]

Since you're doing all this measuring, you've surely done a toe-in reading.

Is it in spec.?

 

[peepers]

please go through and re-tighten all the bolts. mine came very loose and my panhard bolt even fell out while on the highway. doh!

seriously, get under there and give 'em all a once over, I bet some are loose.

 

[powderpig]

If you believe that the bearing preload IS OK. Then I would rotate the tires to see what happens. Or if you have a balance machine or a way to rotate the tires(like on a tire machine or with the drive flanges removed) and see if either the tires are not tracking straight or a wheel is bent. Besides the alignment issues, you have stated this problem has followed the truck with all the work that has been done, but have not stated anything about the tires and rims.
Also have you looked at the frame where the Panhard bracket mounts to the frame for cracks and such?
good luck.

 

[Squash]

Had the same squirrley feeling going from a stocker to a JDM with 4" lift, my guess was tires so off came the Wranglers and on went the BFG's...it is like night and day.