Topic: Steering Stability on 86 4runner w/ 4" SAS

[nadams86]

I have a question about steering stability on my 86 4runner, 4” SAS with 35’s.  The truck runs straight without out a problem at any speed unless I hit a groove or bump in the road and start to wobble.  The wobble is not uncontrollable and goes away, though want to ask if I can achieve more stability.  I believe all my steering geometry is correct with 1/8” toe-in and caster at 5 degree for 4” sas.  I’ve also gone through and retightened everything after around 100 miles of driving, including steering stubs, u-bolts, and wheel/knuckle bearings.  The two things I can think of is shackle stability or it’s just the tires gripping the road.  I have the TG shackles with the bushing to fill the gap between shackle and string.  Would these create an issue for side to side movement since you can’t tightening them down too much?  Any ideas or possible solutions would be appreciated?           

Thanks again,

[sparkys83yota]

Do you have a steering stabalizer?

[nadams86 [OP]]

Yes, stabalizier attached to passenger side frame and tie rod

[4-lo]

check the shims on the knuckle and recheck your tire toe. big plus what kind tire are you running...

[nadams86 [OP]]

I'm running brand new BFG km2 35x1250. Checking the shims on the knuckle, are you talking about the preload? I think they're around spec, about 10lbs.

[dave_dj1]

I read that and thought you were running 10lbs of air in your tires 
What air pressure are you running? I have found on my jeep that the pressure makes a huge difference. Also how are your tires balanced? I've had good luck with 35's balanced with beebees.
Check your spring shackle bolts for the proper torque too.

[Dingman.]

Any time i have had slight death wobble after hitting bumps is because the shackles are loose or the tie rod ends are shot.   With that said,  i have never had death wobble since i got toyos i dont think.

[4-lo]

I'm running brand new BFG km2 35x1250. Checking the shims on the knuckle, are you talking about the preload? I think they're around spec, about 10lbs.

yes the preload....try 15 pound.  when i had that same problem i can hear my tires grabing the road at normal speed (50-55 mph). i checked every thing that i couldv'e thinked of and it ended up being my tire toe/alignment. i'd say toe some more in and take in for a test drive.

[toygasm]

Any time i have had slight death wobble after hitting bumps is because the shackles are loose or the tie rod ends are shot.   With that said,  i have never had death wobble since i got toyos i dont think.

i know on my last two trucks i had to get under there and tighted the shackle bolts once in a while on the front springs.makes a big difference.i also had the studs come loose on my high steer arms when they were new.my new rig has a trailgear hydro assist and it tracks great.even with 37s.