Topic: huge DEATH wobble! please help!

[Broke_Okie_Ty]

ok, heres the scoop. i did an sas on my '92 v6 xtra cab. it has had a bit of a wobble in the front end with 36x14.5 tsl radials on it. heres what i did to try and fix it.

changed steering stabilizer

tightened every bolt from the tcase forward

changed the tires to 32x11.5 desert duelers and it got WAY worse.

if anyone has a suggestion..... im at my wits end   

[Hawk Thor]

How are the bushings in your steering and suspension? Are they worn or are they new?

[79coyotefrg]

i'd be willing to bet good money (that i dont have) that your trunion bearings are too loose,  aka, the knuckle bearings, they are preloaded  using shims top and bottom, if they arent "snug" death wobble  will be yours to love

[Broke_Okie_Ty [OP]]

How are the bushings in your steering and suspension? Are they worn or are they new?

bushings are fine.

i'd be willing to bet good money (that i dont have) that your trunion bearings are too loose,  aka, the knuckle bearings, they are preloaded  using shims top and bottom, if they arent "snug" death wobble  will be yours to love

where do i tighten those up at? do i have to pull the knuckle off? that will be my next try.

thanks for the info

[OOPS]

DW can be caused by a number of things.

Toe in/out not right

Caster not right

Not enought pre-load on knuckle (trunion) bearings

Worn spring bushings

Loose spring/shackle bolts

Worn TRE's

Wheel bearings not adjusted right

Tires not balanced or out of round

Bent wheels

The first thing I would check is the toe in/out and the caster is within spec.

[OOPS]

Here are two links to setting up the front end. One is from the FSM, one is from Roger Brown.

FSM

http://www.lukemiller.org/toys/1985_toyota_4wd_front_axle_FSM.pdf


Roger

http://www.4crawler.com/4x4/CheapTricks/AxleRebuild.shtml

[Broke_Okie_Ty [OP]]

thanks guys im gonna get on it on sunday

[sabenson82]

Check the frame.... when i had a killer case of the death wobbles it was due to the frame being cracked around the steering box and both spring hangers. I had to hack off the frame, from the motor mounts foward, and fab up new frame rails, spring hanger drop box and body mounts.

[Broke_Okie_Ty [OP]]

Check the frame.... when i had a killer case of the death wobbles it was due to the frame being cracked around the steering box and both spring hangers. I had to hack off the frame, from the motor mounts foward, and fab up new frame rails, spring hanger drop box and body mounts.

wow that sounds horrible

if the frame is screwed up wouldnt it have done it with the IFS on it. it hasnt been wheeled yet, so i dont think its the frame, but ll check any way.

[gomezmk]

I had it really bad on my 4runner, I ended up replacing the front leaf spring bushings and it was gone.

[Broke_Okie_Ty [OP]]

yeah i just replaced those when i sas'd it

[79coyotefrg]

yea you have to remove the knuckle, its the bearings that hold the knuckle at the top and bottom,  if they are loose  it will wobble  and nothing will fix that but getting them  set right ,aka removing a shims, or replacing

[Broke_Okie_Ty [OP]]

ok, the studs coming out of the knuckles were loose. i tightened them up without taking anything apart. its still doing it. does that mean the shims and bearings need to be replaced?

[Hammerhead]

What is your caster set at?

[Broke_Okie_Ty [OP]]

no idea. how do i check?

[sabenson82]

There is no caster adjustment on toyota front axles... its a fixed caster set by the trunion (knuckle) bearings...the shims will adjust your knuckle pre-load (should be 12 - 15lbs.) I would snag one of marlins knuckle re-build kits, it'll come with all that is needed.  One way to find out if bearings are bad is to raise the tire off the ground and try to wiggle it from top to bottom....if it moves, look on the inside of the tire and see if just the brake and tire are moving or if the whole knuckle moves.  If the knuckle is moving, your trunion bearings are probably toast, and if its just the wheel and brake rotor, its probably wheel bearings. Sometimes the wheel bearing nuts come loose and the bearings are fine.
Another thing you may want to check is your steering tie-rod ends to make sure they are really tight.

[Broke_Okie_Ty [OP]]

ok, i'll check it tonight

[Broke_Okie_Ty [OP]]

the knuckles didn't move even slightly. however, checked the PS gear box, and the top bracket that is welded on to the frame on either end, is cracked on the side closest to the rear. would that one little weld being broke be enough to make it wobble like it is. but it mite have broke as a result of the DW.

[GJToyotabug]

yes that can cause it to happen too the smallest little thing on steering is doubled at the wheels so even the smallest thing is noticable

[OOPS]

The first thing you need to do is check that your caster is within spec. at ride height. That is the biggest cause of DW on an SAS.

I had it when I first did the SAS and just changeing the rear shackles to one inch over stock my DW went away. I went from six inch bolt hole to bolt hole shackles to four and one half inch bolt hole to bolt hole shackles and it made a world of difference.

This is what the FSM has for caster specs.

  o      +   o
2  15'  -  1

  o      +    o
3   00' _   1

What ever the heck that means !!!!!!!!!

[4runner4x4]

i used to have the same problem on my 82 and it was my shocks they were completly dead and my bushings

[lucky7]

I had a set of iroks come apart from the inside major death wobble. Hows your alignment?

[Broke_Okie_Ty [OP]]

The first thing you need to do is check that your caster is within spec. at ride height. That is the biggest cause of DW on an SAS.

I had it when I first did the SAS and just changeing the rear shackles to one inch over stock my DW went away. I went from six inch bolt hole to bolt hole shackles to four and one half inch bolt hole to bolt hole shackles and it made a world of difference.

This is what the FSM has for caster specs.

  o      +   o
2  15'  -  1

  o      +    o
3   00' _   1

What ever the heck that means !!!!!!!!!

how do you do that?

i used to have the same problem on my 82 and it was my shocks they were completly dead and my bushings

they were good when i put them on, but it did it before the shocks were installed.

im gonna take it in for alignment tomorrow. 

[82juguete]

Ok sorry for the semi hijack but maybe it will help.  I have an 82 with the same problem right now and was thinking...are you running shocks on all 4 corners?  My temporary upper shock mount broke in the rear, so I basically abandoned the rear shocks and was wondering if that might be the cause, because the wobble it consistent and brutal now.  I  have other tire wear issues that I think could be contributing as well though...

[Broke_Okie_Ty [OP]]

no prob with hijack, i do have decent shocks on all corners. however, other tire wear issues is   [llllll]     [llllll]                        going be toe and i think its camber, im not sure if thats the term for the tires being like this       //---\\ , \\---//.
what is the wear like? i havent had my truck aligned yet, thats gonna be my next move. i have run trucks without rear shocks before and never had a problem.

[Broke_Okie_Ty [OP]]

i forgot to tell you guys, i havnt lifted the rear to match the front yet  so maybe that info will help

[82juguete]

Well i discovered that the problem for me is my tires.  They must be completely out of round, unbalanced etc, because I put on some 36x14.5s today and it drove smooth..no DW. (my tires are 33X12.5)  If nothing else seems to be the problem, which was the case with me, it might be worth it to take your tires to a reputable shop and have them do a good job of balancing them.  BTW my drivers side front tire is nearly bald from about the middle in.. i thing this quick, uneven wear is what made the wobble come out of nowhere...

[82juguete]

Wide tires will ride rougher, sure, but death wobble shouldnt ever be normal.  I had 33X12s which i would hardly call wide, and I put on much taller, heavier, wider tires and the shaking stopped.  My problem was def tires, something is out of whack with them.  Just something to check into

[Broke_Okie_Ty [OP]]

no DW is never normal, i meant the middle tread wearing out faster and some uneven wear. compared to the stock 8" wide tires that Toyota designed their trucks for, 12.5"+ are wide. then add lockers and you've just shot your tire tread to hell on a DD.

[bigben75ford]

Hey man Ive got the same problem!I have a 94 yota pickup with an 83' model axle for my SAS.I have aligned my tired myself which were towed in 1,1/2 inches!I have been told to have them towed in to 1/8 to 3/8 of an inch.That helped at first but then kinda started up again.So then i got my tires balanced which didnt help at all.I also blew my birfields up and when I rebuilt the axle I dont know if I put the shims back on the knuckles like all of these guys were talking about.Anyways thats what Im going to try next.I do have 1 tie rod end that is old,the rest are brand new,that 1 couldnt be it could it?