A year of DW.

Last April after a weekend of hard wheeling (The Cove, Corum on 31's a couple times) I drove home uneventfully about 100 miles. Parked for it for 2 weeks and then drove it work and got horrible DW. Been chasing it ever since. The chassis set up is the same as I have run for the two years prior to the DW. Here is what has been done & how the rig is set up:

31's on 4.5" lift

Rear: Trussed Dana 44, Bastard pack, shackle box relocation, 2" lift shackle, 1" block machined for pinion angle (6" long and curved on ends).
Front: HP D30, T-Bird springs plus two extra coil isolators. Rustys adjustable control arms upper and lower with the rebuildable joints on the frame end.
Frame: Plated with 3/16 steel, C-Rok steering box plate.
Track Bar: RE HD. Mount is bolted and welded to frame.
Track Bar Brace: RE bolted and welded on both ends

Here are the new parts since the DW started:
Rebuilt Track bar with new bushings and larger bolt on axle end. New races and ball on frame end. Axle end hole is NOT wallowed out.
New TRE's on tie rod. New TRE on drag link. New drag link.
New rubber bushings on axle end of control arms.
New rubber bushings on both ends of the leaf springs
New races and balls on chassis end of control arms.
New Unit bearings
New Ball joints, upper and lower both sides.
New Steering box.
Used (salvage yard) steering intermediate shaft.

"New" dealer take off ZJ steel wheels. They are straight and true
"New" used tires, AT's. Tires balanced.

All fasteners are TIGHT including rear suspension.

Alignment is 7.5 deg caster, 0 toe. (I have tired a little toe in and a little toe out too along withe 6 deg caster and 8 deg caster. No differences.

Here are the questionable items:

Rear leaf spring is lower at the shackle end than it is at the chassis (big) end. Been like that for a couple years.

The rig has been use HARD since 2004. Prior to plating the frame in 09 you could turn the wheel and SEE the chassis twist, hear it groan and it didnt want to turn in. After plating it was MUCH stiffer.

DW kicks in as low as 35 mph. You can feel it start to build while driving down a smooth road as you pick up speed (makes me think tires). Swapping tires around makes it a bit better (DW kicks in at 45 on a bump) but it can also occur on a smooth but "rolling" road by hitting the throttle hard as the road undulates. I have run as fast as 65 mph on a smooth road but a small bump send it into DW. Feels like the rear kicks into DW as well. Rig jumps up and down when its really bad and chirps tires when you hit the brakes.

I have spent a couple hours under the rig with wife, daughter, neighbor turning the wheel. No slop, clicks, vibrations or motion that should not be there.

Next Steps:
Tire swap with a friend who has a good (no DW rig) on 31's.
Shorter rear shackle, more arch.

Get a new chassis. Could this rig finally be wasted? I lost 55 points on the RTI ramp after I plated the chassis dropped to 715 from 770.

Ideas and suggestions welcome.

John

when was the last time you put a 18mm on a breaker bar and really cranked down on the frame side trackbar mount? what about the last time the tracbar axle side was tightened up?

stock steering?

try another set of tires as well.

also, are your calipers in good shape? brakes in general up front? How are the knuckles?

bent axle housing? twisted a tube in the housing maybe?

pics of steering? pics of front end?







you dont have a hole that is too small or too big on either side of the trackbar , not a wallowed out hole, but a bolt that is too small or a sleeve that is too big ?

Set the toe out about 1/8" and drive it. If it goes away or is dramatically reduced, your DW is coming from the trackbar and or draglink.

Did you plate the inside of the frame behind the steering box? Mine popped and creaked, until the frame split right behind the spacer plate. It's now plated on all 4 sides from the trackbar forward. 3/4" heims on both ends of the trac bar and 7/8" heim joints for drag link and tie rod. Handles great now and not a hint of DW.

blondejoncherokee said:

when was the last time you put a 18mm on a breaker bar and really cranked down on the frame side trackbar mount? what about the last time the tracbar axle side was tightened up?

stock steering?

try another set of tires as well.

also, are your calipers in good shape? brakes in general up front? How are the knuckles?

bent axle housing? twisted a tube in the housing maybe?

pics of steering? pics of front end?

you dont have a hole that is too small or too big on either side of the trackbar , not a wallowed out hole, but a bolt that is too small or a sleeve that is too big ?

Click to expand...

Steering is stock. Tie rod has a solid bar rosette welded inside and 2 pcs angle welded to the outside of it. Quite beefy and stiff. I do bend the occasional TRE but not the tie rod.

Brakes are in good condition. No grabbing or pulling, discs are smooth, 50% pad wear.
Camber is even so the chances of bent axle housing or bent C's is near zero. Nothing visually bent.

The bolts on both ends of the tie rod along with the sleeve and bushing on the axle end are new from RE and are a tight fit.

Bolts on Track bar mount are as tight as I can get them with a 2' breaker bar. Same for the axle end of the track bar. Welds between track bar mount and frame plates do not appear to have any cracks but I have not done a dye penetrant test. I will go back over all the welds and check / re-weld.

Swapping in a different set of tires from a buddies rig is HIGH on the list.

Thanks for the reply.

John

rockclimber said:

Set the toe out about 1/8" and drive it. If it goes away or is dramatically reduced, your DW is coming from the trackbar and or draglink.

Click to expand...

I will add 1/8 of toe in and see how that affects it. Cant see how the track bar or draglink could be bad being that they are both new but its worth giving it a try since its a dead simple test.

Thanks

John

zachandandy said:

Did you plate the inside of the frame behind the steering box? Mine popped and creaked, until the frame split right behind the spacer plate. It's now plated on all 4 sides from the trackbar forward. 3/4" heims on both ends of the trac bar and 7/8" heim joints for drag link and tie rod. Handles great now and not a hint of DW.

Click to expand...

I did NOT plate the inside of the frame rail and the C-Rock plate is NOT welded in. I did pull the plate last summer after this all started and saw no cracks. Definately worth checking again and while I have the box out plating and welding the C-ROCK plate in too.

Its suppose to snow in DC tomorrow and I will probably get the afternoon off from work so it will be a good chance to dig back into this.

Thanks to all for the replies an ideas. I will follow up with what I find.

John

Tires can be balanced but still out of round, which will cause hopping & madness like you describe.
I'd really be looking at tires if you can get the DW going on a flat road, especially if swapping tires around changes anything.
Let the air out of the tires & visually inspect sidewalls, tread area, etc for signs of jacked-upedness.
Or just swap all 4 tires for a weekend and see how it goes.

Took a bit longer to get to it than I had hoped but......


Swapped on a set of tires that a friend had on his rig. No change.

Added one then two turns of the tie rod of toe in. If anything it got worse.
Took it back to original toe, and added one then two turns for toe out. Again it got worse.

Going to look at it some weekend after next (rain and snow this weekend).

John

Only thing I can think of at this point is wheel bearings. Get a wheel off the ground, preferably all 4, and with the tire attached try to wrench / turn / shake the tire. Any motion of the tire (aside from sidewall flex, I mean) relative to the knuckle is unacceptable.

OK, only other thing I can think of - frame side control arm joints, combined with steep control arm angles / steering angles. I'd be super suspicious of those control arm joints in light of everything else that you've been over. Tear them down & inspect for any galling, metallic dust in there, etc.

How old are your shocks? I broke a front shock off and couldn't get over 35mph.After i fixed that i installed known bad shocks to do a test. Guess what, i had DW just as bad as i did with the broken shock mount.

It may sound stupid, but have you checked your lower control arm mounts to see if they are tearing away from the body? I didn't see on the original post if you had done that or had drop brackets. I tore the lower driver mount off the inside twice.