Another possible source of death wobble?

[terryjm1]

I’m back working on another D1 project having successfully corrected the one with the broken shock and clogged exhaust that also received rear dislocation cones as part of the process.

.This is one that needed a lot of odds and ends but I hadn’t yet done anything with the suspension. It has 155,xxx miles and aside from the shocks and a couple tie rod ends the suspension looks original I replaced the steering gearbox because the steering was really sloppy and it had a tremendous leak. After I replaced the steering box it drives quite nice with one exception. Every once in a while I get a brief showing of light death wobble. The new steering gearbox didn’t change that at all.

So, the first step I chose was to replace the panhard bushings. The bushings, particularly the one under the steering gearbox, definitely had a bit of wear. However, one of the bolts was surpringly loose. Here is what I found. I wonder if that was the source of the mild death wobble. I’m going to try the local hardware store for a new bolt.

I will update the post after I get the new bolt installed.

 

[discostew]

Swivel housing preload.

 

[kris812]

Amazon.com

I bought this JUST for the bolts BTW.. 19$ for both. My local hardware stores don't carry Metric in grade 8.. Comes with 2 spare bushings as well!

Also worth looking over the rear A arm ball joint and bushings. But yeah a loose panhard makes for a "SELF DRIVING ROVER" that does whatever it wants to.

 

[terryjm1]

Swivel housing preload.

Next on the list if this doesn’t fix it. It was just the easiest option.

 

[terryjm1]

Amazon.com

I bought this JUST for the bolts BTW.. 19$ for both. My local hardware stores don't carry Metric in grade 8.. Comes with 2 spare bushings as well!

Also worth looking over the rear A arm ball joint and bushings. But yeah a loose panhard makes for a "SELF DRIVING ROVER" that does whatever it wants to.

That’s a great option!

The last one I changed the panhard bushings I had to cut off the bolts because the were seized in the bushing.

 

[p m]

That bolt could have accounted for a lot of play in Panhard rod. Let us know how it works out when you replace it.

 

[4Runner]

I have also run across two different sizes bushing insets.

 

[terryjm1]

I have replaced the bolt (exact replacement found at the local hardware store) and the new panhard bushings seem to have solved the death wobble. I’m not 100% sure the light death wobble is resolved as it was intermittent and infrequent. I also discovered the bottom shock nut on the driver side wasn’t as tight as it should have been. Seems the previous owner wasn’t as careful as they should have been. This is also the one that didn’t have a fuel pump to tank seal installed.

However, I do believe the worn bolt and bushings were an issue. The repair work seems to have resulted in an unintended consequence.

While it seems to track correct, the steering wheel is off center. It was perfectly centered before this.

Would I be correct if I tighten up the rear steering bar and open up the front steering bar equally I will get the steering wheel back to center? That is what I recall from memory.

 

[p m]

The process of centering the steering wheel starts with centering of the steering box - there's a bolt hole in the box casting and a slot in the Pitman arm that should line up when the box is centered. It is important, because the play can only be adjusted at dead center position, otherwise you'll have binding in a turn. Once you have the box centered, if the steering wheel isn't, the proper way to do it is by taking the steering shaft joint off the splines of steering box or/and shaft connecting to the steering wheel and moving it by a spline or two.

There's a very common shortcut to centering the steering wheel by adjusting the length of the drag link (not track rod!). My WAG is that 99% of people who lift their trucks notice off-center steering wheel and tweak the drag link. The result is a lot more play in the steering box, which is another contributor to death wobble. Out of these 99% of people, about 3% attempt to adjust the play in the sector shaft, with disastrous results.

 

[p m]

Would I be correct if I tighten up the rear steering bar and open up the front steering bar equally I will get the steering wheel back to center? That is what I recall from memory.

No. The rear link - a.k.a. track rod - adjusts toe in/out. As far as centering the steering wheel using front link - a.k.a. drag link - see above.

 

[terryjm1]

I recently replaced the steering gearbox in this one and the box was centered as described. No lift on this one, either. I’m going to drive it around a bit and make extra sure it is tracking correctly before I adjust anything else.

 

[ukoffroad]

That’s a great option!

The last one I changed the panhard bushings I had to cut off the bolts because the were seized in the bushing.

My last classic was like that, most bolts had to be cut.

 

[p m]

I recently replaced the steering gearbox in this one and the box was centered as described. No lift on this one, either. I’m going to drive it around a bit and make extra sure it is tracking correctly before I adjust anything else.

That's great, you just need to pull the steering shaft off the splines and reseat it a couple of splines off.

 

[terryjm1]

That's great, you just need to pull the steering shaft off the splines and reseat it a couple of splines off.

Just returned from a 20 mile drive. No wobble whatsoever. I think the steering was a little tighter as well. I will do just as you suggested in the morning.

 

[kris812]

Easy fix on the steering wheel.. There is a track rod going from steering-box to right wheel.. Loosen up clamps and hit with a hammer in their V to get them loose. Then put a pipe wrench on the bar. You need to make that steering link rod "longer" and judging by the wheel, 1/2-3/4 of a turn should be about right. Check wheel driving around before putting clamps back on.

Might require a blow torch on the ends to get yours to turn, mine was seized. Easy job, doesn't mess with ANY of the alignment of the front toe.

And neither does the panhard or bushings. Just the axle's position, thus the steering linkage changed.

The Toe rod is in the back, don't touch that one.

 

[p m]

Easy fix on the steering wheel..

That's not a fix, this is a hack (mentioned earlier).

 

[kris812]

That's not a fix, this is a hack (mentioned earlier).

I understand and I agree. However I doubt the person that aligned the toe rod in the rear to Center in the gearbox didn't take that into account, or it's never been moved.

If taken to a shop for an alignment more than likely a young money wrench just turned whatever is easiest to get the wheel centered and called the toe correct by kicking a tire. Pun intended..

But worthy of noting the pitman arm should at least be pointed forward whenever the steering wheel was centered and vehicle tracking straight.

Being a stock vehicle, I bet an alignment shop/owner just turned this front rod as the bushing wore to get the wheel straight and sent it.


No hate, you're 100% correct on everything you said!

 

[p m]

I understand and I agree. However I doubt the person that aligned the toe rod in the rear to Center in the gearbox didn't take that into account, or it's never been moved.

If taken to a shop for an alignment more than likely a young money wrench just turned whatever is easiest to get the wheel centered and called the toe correct by kicking a tire. Pun intended..

But worthy of noting the pitman arm should at least be pointed forward whenever the steering wheel was centered and vehicle tracking straight.

Being a stock vehicle, I bet an alignment shop/owner just turned this front rod as the bushing wore to get the wheel straight and sent it.


No hate, you're 100% correct on everything you said!

Wasn't aimed at you - we [almost] all are far removed from the original ownership. This is such an easy "fix" compared to reseating the steering shaft or wheel that almost everyone does it, shops included. There's always a chance that the person would return to the shop with wobble complaints, which is a bonus.
Not to knock all shops, either - I was told of this distinction by an indy shop owner, who I've trusted with whatever jobs I was too lazy to do by myself for almost 25 years.

 

[terryjm1]

I confirmed the pitman arm was in the correct location and then reseated the steering column shaft to the steering box.. After 5 tries to get it perfect I settled for almost perfect. Each time I moved it, it was either a just a bit right or left of center. I think I may be one spline off. It’s pretty hard to be exact as when you slide it back off it is hard to keep it exactly in place considering how such small changes there move the steering wheel. I may try once more tomorrow. My brand new GMC was slighty off center from the day I picked it up. After two trips to get it corrected at the dealer I gave up and just lived with it. I don’t know why I can’t let myself off easy like I did the dealership.

 

[terryjm1]

“Being a stock vehicle, I bet an alignment shop/owner just turned this front rod as the bushing wore to get the wheel straight and sent it.”

After fighting this for a couple hours I suspect you are quite correct as it was dead center before I replaced the panhard bushings and now it doesn’t want to be perfectly center again.