Long one. Sorry. But I'd rather front-load it than get twenty replies telling me to check my caster.
1990 HDJ81. 4" lift, Delta 5L radius arms with 2.5* bushings stacked on top, 37x12.50R17 Mickey Thompson Baja Legend EXP on -38 offset beadlocks.
Symptom, and I want to be precise because I think the wording matters. This is not the loose, floaty wander people usually describe. Mine feels sticky. Small steering inputs meet resistance, so when the tire drops into a rut or groove the road wins and pulls me over. Then I correct, and it doesn't ease back, it holds and then breaks loose all at once. So I'm sawing left and right the whole way down the freeway.
The wheel does not self-center. Turn it at low speed, let go, and it mostly stays where I put it.
Done already:
Steering box rebuilt by Redhead
Frame reinforcement plates at the box, no cracks
U-joint at the box is brand new
Knuckles completely rebuilt, trunnion preload set at 12 lbs, 1000+ miles ago
All bushings replaced
Panhard corrected, axle centered
All new suspension components
Dobinson adjustable stabilizer, backed all the way off, no change
Alignment printout, Aug 14:
Caster 4.0 LF / 4.2 RF
Front total toe 0.17
Steer ahead 0.00
Thrust angle 0.03
Rear total toe 0.30 (haven't chased this yet, open to opinions)
Tested and ruled out:
Tire pressure. Ran 35 all around, then 40 front / 35 rear, then 40 all around. Steering effort got slightly lighter at 40 front but the crown-follow and the sawing didn't change.
Stabilizer damping. All the way soft, no difference.
Where my head is at. I don't think anything is broken. I think the caster is generating a return force and friction somewhere in the chain is eating it before it reaches the wheel. Sticky on small inputs points at bind, not wear. Candidates I haven't isolated yet: trunnion preload set at the top of spec and maybe not settling?
Questions:
1990 HDJ81. 4" lift, Delta 5L radius arms with 2.5* bushings stacked on top, 37x12.50R17 Mickey Thompson Baja Legend EXP on -38 offset beadlocks.
Symptom, and I want to be precise because I think the wording matters. This is not the loose, floaty wander people usually describe. Mine feels sticky. Small steering inputs meet resistance, so when the tire drops into a rut or groove the road wins and pulls me over. Then I correct, and it doesn't ease back, it holds and then breaks loose all at once. So I'm sawing left and right the whole way down the freeway.
The wheel does not self-center. Turn it at low speed, let go, and it mostly stays where I put it.
Done already:
Steering box rebuilt by Redhead
Frame reinforcement plates at the box, no cracks
U-joint at the box is brand new
Knuckles completely rebuilt, trunnion preload set at 12 lbs, 1000+ miles ago
All bushings replaced
Panhard corrected, axle centered
All new suspension components
Dobinson adjustable stabilizer, backed all the way off, no change
Alignment printout, Aug 14:
Caster 4.0 LF / 4.2 RF
Front total toe 0.17
Steer ahead 0.00
Thrust angle 0.03
Rear total toe 0.30 (haven't chased this yet, open to opinions)
Tested and ruled out:
Tire pressure. Ran 35 all around, then 40 front / 35 rear, then 40 all around. Steering effort got slightly lighter at 40 front but the crown-follow and the sawing didn't change.
Stabilizer damping. All the way soft, no difference.
Where my head is at. I don't think anything is broken. I think the caster is generating a return force and friction somewhere in the chain is eating it before it reaches the wheel. Sticky on small inputs points at bind, not wear. Candidates I haven't isolated yet: trunnion preload set at the top of spec and maybe not settling?
Questions:
- Anyone at 4" with correct caster who still had this, what turned out to be the source
- If you run Delta 5L arms, did you stack correction bushings on top like I did, and did Delta have an opinion on what that does to the axle's fore/aft position and the panhard relationship
- Anyone measured breakaway at the knuckle after 1000 miles on a fresh rebuild, does 12 lbs hold or drop
- Raised steering arm or panhard drop bracket at this height, did either actually change how it drives
- Anyone on hybrid tires (Baja Legend EXP, Ridge Grappler, KO3) think the tire is carrying real blame here
