My FJ40 is actively trying to kill me - steering help please

[JohnJL]

I did a frame-off restoration and upgraded a bunch of parts along the way only to end up with the truck handling very sketchily. These are all new tie rod ends, shackles, springs, bushings and the axle/birfs/bearings all new. Toe in is 1/4" on 31" wheels. 4degree caster wedge. New Bilstein 5120 and stabilizer.

Here's what I am experiencing;
1. Truck wanders all over the road
2. Bumpsteer in the extreme
3. Exaggerated brake dive

At first I thought it was the drag arm hitting the front shock but I relocated/adjusted the steering box inboard and they no longer contact. The front springs are new from Alcan. They look a bit longer/the front shackles are slanted more that I member seeing on the truck before.

The front steering arm drops a long way down, I seem to recall it being preferable to get that steering arm from the center arm to the right knuckle as close to horizontal as possible.

I am thinking...

...do I need a drop arm on the steering center or a lift arm on the right drivers' knuckle? Revalve the shocks more stiffly? Shorter or more curved front springs?

ITs killing me to to be able to drive this thing...but it is absolutely dangerous right now..

 

[Pighead]

You've re-torqued your U-bolts several times since driving it?

 

[DangerNoodle]

Is your steering box lose/worn? If you are drifting all over, something is probably lose. I'd be skeptical of all the ends as well. If you have the crank adjusters on the drag links(s) try tightening those up as well.

All end clamps good and tight?

2X on the tightness of the U bolts.

Are the springs stock rates or are they completely custom? How much can you move the front if you push up and down on the bumper?

 

[DangerNoodle]

Also, shock boots are so 90's. You should pull them IMO. Gives debris and moisture a path to escape as well.

 

[pb4ugo]

What is your front caster angle? You mention "4*caster wedges" but I dont see them installed in the frt. . If they are installed they might be backwards. The fat end usually goes towards the frt to get positive caster. Negative caster will make it wander and react snappy, white knuckled. Are they steel shims? Your drag/relayrod link is awful steep which will create bump steer. Having stk steering, Im not sure there's anything you can really do with it.

 

[pb4ugo]

It looks like the relay rod clamp at the pass side tre has slid off the rod tube. It looks like your missing a bunch of lug nuts too.

 

[hobbes]

What is your front caster angle? You mention "4*caster wedges" but I dont see them installed in the frt. . If they are installed they might be backwards. The fat end usually goes towards the frt to get positive caster. Negative caster will make it wander and react snappy, white knuckled. Are they steel shims? Your drag/relayrod link is awful steep which will create bump steer. Having stk steering, Im not sure there's anything you can really do with it.

This. Your caster wedges appear to be in backwards, but it’s hard to be sure from the photos.

When I did my front end, I assembled everything per the manual. Then I took it to an alignment shop for them to do the final setting and give me exact numbers. I called @cruiseroutfit with my numbers and they sent me caster blocks to dial in my setup. A little extra work to do it that way, but it drives great.

HTH.

 

[Shark56]

Wedges look backwards.
Pinion looks like it is pointing up.
Looks like the sliver of silver is the Caster Shims?

 

[firemanj92]

Also check your tire pressure- make sure your tires aren't over inflated to the "max tire pressure" of 50 psi since they look new.

 

[jim land]

The shim is backward as note above , the thick side go to the front, and it is clearly the problem

 

[jim land]

You still need to fix the other things like the loose clamp on the relay rod and the way too long steering stop
X2 for shock boots off

 

[JohnJL]

You've re-torqued your U-bolts several times since driving it?

Yes, thanks though I have made that mistake before.

Is your steering box lose/worn? If you are drifting all over, something is probably lose. I'd be skeptical of all the ends as well. If you have the crank adjusters on the drag links(s) try tightening those up as well.

All end clamps good and tight?

2X on the tightness of the U bolts.

Are the springs stock rates or are they completely custom? How much can you move the front if you push up and down on the bumper?

It didnt seem to have any play in the box. It didnt have a heat shield to protect from exhaust manifold and pipe but I made a pretty one up to try and extend its life. One clamp was loose as pb4ugo noted. I clamped the other end for the drive around the block and agree need to tighten the lower one too. It wasnt moving in this case so not the cause of my issue here. The shocks are stock valving, I can grab the label. I can move it up and down with my full body weight/strength of 180 lbs.

Also, shock boots are so 90's. You should pull them IMO. Gives debris and moisture a path to escape as well.

Funny I was considering it too.

What is your front caster angle? You mention "4*caster wedges" but I dont see them installed in the frt. . If they are installed they might be backwards. The fat end usually goes towards the frt to get positive caster. Negative caster will make it wander and react snappy, white knuckled. Are they steel shims? Your drag/relayrod link is awful steep which will create bump steer. Having stk steering, Im not sure there's anything you can really do with it.

I think you may have nailed at least one (and hopefully main?) problem. I did indeed install the shims fat-side-back and I assumed it was angling the pinion properly but seems I got it backwards!

It looks like the relay rod clamp at the pass side tre has slid off the rod tube. It looks like your missing a bunch of lug nuts too.

Yes I left that one loose but will tighten up. THe lug nuts are black, all there (though I have also left some loose accidentally in prior attempts!)

This. Your caster wedges appear to be in backwards, but it’s hard to be sure from the photos.

When I did my front end, I assembled everything per the manual. Then I took it to an alignment shop for them to do the final setting and give me exact numbers. I called @cruiseroutfit with my numbers and they sent me caster blocks to dial in my setup. A little extra work to do it that way, but it drives great.

HTH.

Thanks. My local shop closed so I dont have a go-to guy anymore. You guys are it!

Wedges look backwards.
Pinion looks like it is pointing up.
Looks like the sliver of silver is the Caster Shims?

You are right, will switch and see if its better. THanks!

Also check your tire pressure- make sure your tires aren't over inflated to the "max tire pressure" of 50 psi since they look new.

There is a 0.5 psi BMW joke in there somewhere ;3-)

The shim is backward as note above , the thick side go to the front, and it is clearly the problem

Thanks!

You still need to fix the other things like the loose clamp on the relay rod and the way too long steering stop
X2 for shock boots off

Thanks!

 

[pb4ugo]

A couple of degrees can make a huge difference in handling. Reversing the shims with the fat end forward will adjust the angle by 8* towards the positive and most likely cure your problems. I bet driving that thing with over 4 degrees negative caster had to be a handful. You may not have to do any adjustment with the steering box, proper caster will feel less sloppy, and track down the road nicely.

 

[pjohnson]

I think you may have nailed at least one (and hopefully main?) problem. I did indeed install the shims fat-side-back and I assumed it was angling the pinion properly but seems I got it backwards!

Fix the caster first and then re-assess. The bump steer may not be that bad after the correction, although it is kind of steep. It might get better after the springs settle.

The brake dive issue probably isn't related to steering, but it also may feel a little better when the truck isn't wandering around.

 

[B y r o n]

Hard to tell from the photos but how did the spring pins fit the hole in the axle pads? They should be a snug fit, no play. If there was play the axle could be out of alignment.

Try setting the toe in to 1/8" as 1/4" might be a little excessive.

 

[Downey]

My 2 cents, first photo above seems to show big gaps between spring, bushing collar, and shackle- - -seems like spring would walk from side to side inside that spring shackle ???.