I'm at my wits end with this thing... It's getting reallly annoying and has been going on for the entire time I've had the truck

The wobble comes on at about 55 and will erratically wobble from 40-50 then it just has a constant faint thudding sound at 65.

So far I've tried:
- Different tires and wheels
- Shimming the kingpins tighter
- Swapping Rear hubs
- New front wheel bearings
- Repacked all wheel bearings
- Tightening body mounts
- Tightening shock mounts
- Check front suspension/ track bar for play
- Limiting rear suspension up travel
- Putting the truck in neutral at those speeds
- Runout of front rotor .010"

The smaller tires and wheels made it less apparent but not gone.

The shake at 40-50 kinda feels like the frame/suspension bouncing around possibly due to the stiffer boxed frame?

Either way it doesn't make sense to me and I'm getting sick of this. Anyone have any good insight?

Have you checked your caster yet?

drivelines

Have you checked your caster yet?

Also do you have a steering stabilizer? If your castor is wrong a stabilizer could take care of the prob. What about free play in the steering box?

I do have a steering stablilzer. I haven't measured my caster exactly but I know it's close. What's a good angle? 5 degrees or so?

My steering box does have some play in it but not a whole lot.

I took a shim out from my kingpins yesterday and it made it a little worse so I think if I shim the hell out of them it may go away completely but then it may handle like shit.

I think if I do that and take the steering stabilizer off and maybe tighten up the steering box and possibly add some caster, it may work.

I'm gonna try it today. Ugh.

5-7* of caster is good. Check it and see where it sits currently.

uhhhhhhhhhh drivelines

uhhhhhhhhhh drivelines

Nope.

Brand new driveshaft tight as anything and it did it with my last brand new shaft.

It's more of a hop than a vibration anyway.

Shocks are good. Track bar is tight.

I rebuilt my steering shaft the other day which helped a little.

I crammed big washers under the kingpin caps which made it handle like shit and still wobbled.

I'm stumped.

Have you checked your TRE's for excessive play?

Yep those are brand new too...

The only bushings/joints that are not new are my shackle/spring eye bushings in the rear but I can't really see much play in those when shaking the truck side to side.

What size tires? With the big meats you need to shim the shit out of the kingpins, period. Although, something is really odd if shimming caused it to handle worse. Steering stabilizer is all fine and and good, but its a band aid not a solution. Go ahead and have it aligned, too. I know you can get it pretty close in the shop, but since your having problems you might as well hedge your bets. Also, an old gasser trick is to toe the tires in a bit to help them track better.

I'm only running 35" BFGs...

When I shim the kingpins that much the thing will hunt all over the place and just not handle right.

I don't notice much difference with the stabilizer on or off.

It's a weird pheonomenon.

I would go get it aligned but I don't know any place that I'd be comfortable about them doing it right seeing as it's a ranger with a 60 front...

Shit, thats weird...you shouldn't have to really even shim them with that size tire. You really need to find a place that can align it. But barring that, try to tip in the toe like I mentioned.

this might sound stupid but jack up each tire and spin it while looking at a yard stick behind it, make sure they all run round, we had this issues on the mack once, got new tires and they still had a hump in it, and with 80,000# you really felt it. if you spot a bad tire you can get them cut to be round

I would go get it aligned but I don't know any place that I'd be comfortable about them doing it right seeing as it's a ranger with a 60 front...

I don't know where you live in MA, but i have a lifetime alignment at expert tire...i've been to the one in fitchburg many times with no problems at all. They don't care, and i have a 44 up front.

It can be hard to find a competent shop that don't act like huge vaginas when it comes to aligning modified vehicles...but they're out there. The odd thing is, Mook's checked and ruled out all the usual suspects and you can get it close enough yourself at home that it shouldn't result in the dw he's experiencing. I still say tip the toe in and if you can't find a place to throw it on a rack have a buddy go over everything you already checked. I know in the past I've gotten frustrated over a problem and missed stuff. All it takes is one worn tre.

are you runnin dualy hubs?
try more caster and less caster.


when i put new tires and wheels on that had more of a scrub i had to take out some caster

I've tried more and less caster.

It feels like the truck is bouncing and it comes from the rear tires too.

I would suspect a balancing problem... BUT

I have them balanced with airsoft BBs and have also had them balanced at a shop with the BBs still in them. Didn't make a difference. I think I'm gonna try loading them up with more BBs and see if it helps.

I'm running SRW hubs for reference.

I've also had the problem with the TREs and my last setup with heims.

I have them balanced with airsoft BBs and have also had them balanced at a shop with the BBs still in them. Didn't make a difference. I think I'm gonna try loading them up with more BBs and see if it helps.

I would, more won't hurt and with the airsoft pellets being so light folks often don't add enough.

Are you running a carrier bearing in the driveline?

Are you running a carrier bearing in the driveline?

It's a pretty short driveline and it's a cv shaft so; no.

The wheelbase is like 113".

Have you checked to see if your u-joints are in phase with each other? That plays out differently with a cv shaft but I'm curious what the angles are, especially with the short length of the shaft.

My pinion angle is in line with the shaft. The driveline angle isn't bad since I had to tip it down to fit the engine and trans.

The shaft is still a good 42" long so I don't think it's having vibration issues.

i wouldnt rule out the frame box job or if your suspension is all custom. maybe not joints but something welded to the frame out of whack or maybe warped? if its been like this since u built it its probly not something worn out

I have been toying around with the idea that the natural frequency of the frame is in the range of the frequency of wheels spinning but I dunno.

I have them balanced with airsoft BBs and have also had them balanced at a shop with the BBs still in them. Didn't make a difference. I think I'm gonna try loading them up with more BBs and see if it helps.


I know its a pain in the ass but how about taking out the airsoft BB's and then getting them balanced. I've heard it's hard to get tires spin balanced with BB's in them.
If anything, you can check it off the list of things you've tried.
Good luck man.

I have been toying around with the idea that the natural frequency of the frame is in the range of the frequency of wheels spinning but I dunno.

Doubt its anything so complex, but its a hell of theory!

I put a hydraulic steering assist on my f350 and cured all steering and death wobbles. Even with unbalanced wheels and tires the wobble won't show.
With balanced wheels the ride is MUCH smoother though.

I've cured Death wobble on 2 trucks this way. Don't even bother with dampers or caster anymore.

Good luck with your truck.

I put a hydraulic steering assist on my f350 and cured all steering and death wobbles. Even with unbalanced wheels and tires the wobble won't show.
With balanced wheels the ride is MUCH smoother though.

I've cured Death wobble on 2 trucks this way. Don't even bother with dampers or caster anymore.

Good luck with your truck.

Hmm. That's very interesting. I will look into that for sure.

I have a little more evidence today. I looked out my window and it looks like my drivers' front tire is hopping up and down when the wobble is happening. It's still really pissing me off.

Hmm. That's very interesting. I will look into that for sure.

I have a little more evidence today. I looked out my window and it looks like my drivers' front tire is hopping up and down when the wobble is happening. It's still really pissing me off.

could it be a bad shock? sounds stupid simple...


how about worn bushings where the arms tie to the frame?


edit: this is ASSuming you've got radius arms, not leafs

could it be a bad shock? sounds stupid simple...


how about worn bushings where the arms tie to the frame?


edit: this is ASSuming you've got radius arms, not leafs

The bushings are all pretty tight. The shocks are fairly new Doesch tech units and they seem pretty good I don't see any leaks or anything.

I put a hydraulic steering assist on my f350 and cured all steering and death wobbles. Even with unbalanced wheels and tires the wobble won't show.

The ram does act like a very effecting steering stabalizer....far better than shocks. While it CAN effectively mask it, its still a band aid not a cure.

What do you think about tightening the backlash in the steering box?

Death Wobble is really hard to track down. It can be caused by a bald tire to a combination of worn out stuff in your truck.
I tried to fix it by replacing shocks, stabilizers, steering ends, ect...
But it didn't go away till i put in a new steering box with hydraulic assist.
Now it could be that the steering box was bad to begin with, Cause i've killed 2 boxes on my truck already, But since the setup with the ram assist, i haven't killed a steering box yet.

Big tires and Wheels with small Backspacing puts more leverage on the steering. It could even be the frame flexing where the steering box mounts.
But with the hydraulic ram, You basically tie the steering knuckles to the diff housing taking ALOT of the stress off the steering box and frame. The ram works as a damper and doesn't let things move around unless you blow a seal or bust a hose.


You'd be surprised how bad the tires shake and bounce when they wobble.
I watched a truck that had DW while it happened and saw the tires leave the ground about 6 inches each. Alternating left and right and the tires turned and jumped back and forth. The steering wheel was held straight but the knuckles would oscilate back and forth . It usually didn;t go away until you came to a complete stop. A small bump would usually set it off.

Good luck.

I went through the entire front end again today tightening everything. I don't see any play anywhere. I still have a wobble/hop though. It may have even gotten worse as I swapped the two front tires.

I'm hopfully taking it to a tire place tomorrow to be aligned and possibly balanced.

maybe a slighty bent axle housing or axleshaft
could be bent ever so slightly only causing wobble at higher speeds

Well I just wasted $100 getting all the tires cleaned out and balanced on a machine. Still wobbles. I think I'm gonna just part this truck out and start over because this is ridiculous now. The thing rides like shit and I'm not into it. There's nowhere to wheel around here anymore anyway.

If your running a spool in the rear, check tire pressure on both sides. My toyota used to do something very similar to what your describing, and i noticed one rear tire was around 13psi and the other at 21. When i aired the low one up, the bounce seemed to go away almost 100%. When it was wobbling it felt almost like i was driving slow over tons of small speedbumps, but was moving at around 35-40 mph. Bounced me enough to be moving up and down in my seat. And at freeway speeds it felt smoother but was still there. I dont know if its the same problem, but it sounds similar to mine. You have probably checked tire height / psi but i thought i would throw it out there.

That sounds similar. The highway wobble is gone which was probably the tires. It still rides like it's going over a bunch of speed bumps though.

I have an ARB and check my tire pressure.

I think it may be the bushings in the rear suspension since they are all cracked. Also do you think shackle angle would have anything to do with it? Right now it's a little past 45* towards the front.