Steering wobble

[ffighterdaddy]

Hello everybody, I have been searching this forum and cannot find a single post about the "death wobble" in our solid front axles. I have a 1985 K30 CCLBD, 6.2dsl and SM465. I have replaced the spring bushings in the front suspension, adjusted the alignment, checked everything under the front and the only thing i can find that is loose, to my naked eye, is the steering box. It has a little play. the drag link seems tight, the tie rods seem tight, my kingpins seem tight...I CANNOT FIND WTF the problem is and why it shakes like it's going to fall off?!?!?! Any help here is very much appreciated and desperately needed. Thanks

[DmaxMaverick]

Welcome aboard!

The loose steering box is definitely a suspect. Every joint in the system is suspect, but the close you get to the wheels, the more forgiving it is. A bad rag joint or pitman arm are highly suspect. Both can cause exaggerated feedback, resulting in the wobble.

Check/replace the tires. A separated cord, even if you can't see it, will do that. Jack the wheel and give it a good spin. If it's not "round", or the tread "walks" side to side, it's separated. Sometimes they'll have an obvious bulge, but not always where you look.

[Yukon6.2]

Hi ffighterdaddy
I have the death wobble on my truck on ocasion.So far i keep it in check by rotating the tires,and replacing the steering damper when it gets bad.
The problem is the bearings that are used as the ball joints/king pins.You have to take them apart and replace them with new bearings.
I have a differant front end for my truck so i havn't done it.My last tow truck had the same issue,it was a dually so the damper didn't last as long.
I belive i have a rebuild guide somewhere if you need it.
Thomas

[CoyleJR]

I agree with DmaxMaverick look for a loose steering box first and also look for a cracked frame at or near the steering box bolts. Additionally, check for out of round or badly out of balance tires. If you still have the shaking issue you should consider buying a steering dampening shock kit.

With the tires on the ground have someone turn the steering wheel while you look at the steering box from above. If the frame is cracked it will be very easy to see. Yesterday I welder the frame on my neighbor's 85 Suburban and installed a reinforcing kit that he purchased at a off road shop. Loose steering boxes and cracked frames are a common problem especially if you added large tires and wheels. Let us know what you find.

Good luck
John

[OIL BURN]

Had the wobble on a 79 and 83 chev trucks,the cause on both were cracked frame on mounting bolt areas at steering box. Cleaned up the area,welded the the crack line starting a little past the crack end up to the bolt hole,ground down the weld leaving it a bit above the frame surface for strength,shimed the gear box with washers so the box would make contact with the frame equally at all four points yet be above the weld peaks,peaks being about an 1/8 inch high,problem solved.There were 4to5 cracks total 1at 1hole ,2at another,and 3 at third,the third having one over an inch long,

Good Luck

OIL BURN

[Dvldog8793]

Howdy
I have repaired many cracked frames in the steering box area. The steps listed above will work. I also weld and grind and then use a larger plate drilled and welded to the frame. Heat stress in the weld areas can cause them to crack again right along the weld zone. A new plate solves this problem.
Good luck!

[Robyn]

One area that really needs to be looked at is the alignment.

The solid axle trucks are fussy about this. (At least some are)

You need to make sure that the caster angle, camber and especially toe are spot on.

If for some reason the caster has gotten to close to or is a positive setting you have the prime ingredients for the death wobble.

Toe out rather than toe in can also get it going.

Caster is my first suspect.

As mentioned, any looseness can contribute greatly

Be sure all the components are in good order, then get the front end alignment checked.

After this, if the creature is still slightly prone to wobble, install a dual stabilizer shock set on the main tie rod.

The truck should have one from the factory, but the stock units were marginal anyway.


The biggy though is the alignment, and then only after fixing any worn parts.

As mentioned, TIRES yeah buddy..
A set of tires that are dynamically out of whack, can really start the front end to oscillating.

If your tires are in good order, try having a product called EQUAL installed in the tires.

This IS GREAT STUFF, and balances the tire continuously, and will take care of almost any balance issue.

I ran this stuff on my class 8 rig on the fronts (385/65/22.5 super singles) and it's great stuff.

Normal stick on weights can leave things wanting.

Just an FYI
IF you find cracks where the steering box bolts on, you need to carefully drill a 1/4" hole through the frame just beyond the end of the crack. Counter sink holes lightly to remove the stress riser.

Then grind out out the crack well, now weld the crack up followed by grinding the area smooth. Do not weld the inside.

Cut a 1/4" thick steel plate and place inside the frame, then transfer the bolt holes and button it up.

Break all sharp edges on the plate, and slightly round all corners.

If you have room, extend the plate fore and aft of the steering box some to help strengthen the area.

If you can get some extra holes (already in the frame) to transfer into the plate, do it.

Welding the frame is always an iffy thing, but when its cracked, there is little choice.

If you have room, a doubler plate on the outside of the frame directly behind the gear box would be good too.
Sandwich the frame between two 1/4" plates

As a friend of mine when we were little kids used to say "More Gooder"

Make sure after doing and work on the holes, to take a countersink and lightly chamfer the holes to remove any sharp edges (just a light chamfer 1/!6")

Do this even on the new plates.

If you plate the outside behind the box, you can skip weld the plate to the frame top and bottom DO NOT WELD DOWN ACROSS THE FRAME.

A little weld of 1 inch long, front middle and back on the top and bottom is great.
No need to weld the inner plate.

Be sure to use GRADE 8 BOLTS with the locking nuts on this area.

Good luck


Missy

[rustyk]

Check also for warped wheels...

[Subzilla]

I agree with Robyn for the caster. When I gave my '83 a 4" lift, the kit included angled shims for the front end. I installed them to turn the diff up toward the transfer case thinking this would minimize the ujoint angle. As soon as I hit a dip in the road, my wheels rocked and rolled all over the place. Scared me. The 4x4 shop took a look at it and said to reverse the shims to get the caster back where it needed to be. Fixed it instantly.

Also to fix the steering box/frame cracking or to prevent it as described by Robyn, try these stuff: http://offroaddesign.com/catalog/steeringkit.htm

Put them on my 2 trucks and haven't had an issue with frame cracking.