02 TJ death wobble, 08 Superduty swap...wth steering box woes?idk

marty79

Well-Known Member
Joined
Dec 2, 2015
Location
Newton, NC
Sorry it's long....wanna be thorough in explaining
need a little direction here as I'm baffled on this. This ain't my first 1Ton swap by far haha, but this one is being a bugger for some reason.
Just did this 1Ton swap in a TJ with 08 Superduty Axles, new ball joints, new wheel bearings, new factory tie rods, new radius arms with 1.25"Heim joints on frame side, Track bar with 1.25"Heim joints on both ends, Drag link is dead nuts parallel with Track bar, New 14"Coilovers just installed at same time, Caster is right at 4.2, Toe is perfect right at 1/8" in, Brand new 35s balanced checked twice....freaking death wobbles like no tomorrow if you hit a bump at speed or launch it from a stop with the Gen 5 it has, not that it matters but it does haul ass being only on 35s....
the ONLY thing left that has "play" in it is the steering box/sector shaft/pitman arm. Has A LOT OF PLAY when your anywhere but straight...I've tried adjusting it and doesn't do anything, takes up some of it but then it's super tight when straight and drove terrible...so i put it back to where it was.
Question: Is this Steering Box play my Culprit? or the Radius Arm Bushings are the only part left stock or unchanged on the axle but I'm just not convinced that they are the problem. Ford says they don't carry them cause they pretty much never sell them. Had a friend send a Ford Master Tech over to look at it and he found nothing wrong either and is assuming steering box as well at this point...he doesn't believe it's the bushings either cause he works on mostly Superduty Trucks and practically never changes them?!!?! idk, but I've been to his shop and he knows them trucks but doesn't really know anything related to these axles being under a jeep with Coilovers and Heim joint/etc etc.
Is 4.2 caster not enough? I see some say to run 6-8* but dam that's a lot. Pinion is already parallel with the ground. I'm checking Caster on top of the knuckle where Tie rod mounts (where Ford guy told me to check it)
The ride height is only equivalent to the same 4" lift it had before so it's not sitting super tall, angles on everything is pretty mild.
Customer ordered a Red Head steering box and I'm installing Hydro assist when it shows up cause he was going to do that in the near future but looks like now is the better time lol.
At this point I'm wanting to learn why it's doing this rather than just replace the steering box with hydro assist and call it good. (I'm 99.9% positive the Red Head box and hydro assist will make the wobble go away weather or not it fixes it or just masks the problem like dual stabilizers would but I'm not satisfied with that one bit. I want "to know 100%" that it's fixed and have a piece of mind that me and the customer can safely enjoy all that power it has without having fear when hitting an overpass. Going over a bridge or hard bump is about mostly when it does it but dam it lets loose at 65
 
Death wobble is a result of uncontrolled movement in the lateral direction, which 99% of the time is a result of the track bar connections or the steering connections. There steering box could be a contributor. Another thing to check is tire pressure. Some tread patterns respond strangely if they are very overinflated or underinflated.
 
which 99% of the time is a result of the track bar connections or the steering connections. There steering box could be a contributo
Yessir I know track bar is good, overkill actually but steering box isn't so It about has to be the box
 
Yessir I know track bar is good, overkill actually but steering box isn't so It about has to be the box
Have you had someone rock the steering while you watched every single joint?
 
Have you had someone rock the steering while you watched every single joint?
Oh cmon were way beyond that lol. Me and a friend just did a few night ago again for an hour and I start seeing things that aren't there haha (more like wishing to find something).
But yes I've spent countless hours looking this thing over
 
Another thing to check is tire pressure. Some tread patterns respond strangely if they are very overinflated or underinflated.
I recently put new wheels and tires on my '04 Dodge 3500 (not exactly known for great steering). I went from from 35" Toyo ATs to 35" Yokohama MTs. I had them mounted and balanced at Discount tire. Immediately the truck was sketchy as hell to drive. It followed every groove or bump in the road, and going around curves with any speed it felt like the you were just waiting for the rear end to start sliding out. I checked tire pressures and I believe they were at 50 psi, or maybe 55. I dropped them to 45 and it seems to have made a world of difference.
 
He had these new 35s on the D30 for 4month before the swap and he said tires made a world of difference compared to old 35s so can't be the tires..thanks guys keep it coming lol.
 
Double check the tires and chase every little bit of slack you find and tighten it up. Wiggle test the steering with the weight on it to see what is moving and tighten it up. i have had several like this they are a pain to fix. Had to go to hydraulic assist on one to fix one it kept coming back after a month of driving.
 
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Double check the tires and chase every little bit of slack you find and tighten it up. Wiggle test the steering with the weight on it to see what is moving and tighten it up. i have had several like this they are a pain to fix. Had to go to hydraulic assist on one to fix one it kept coming back after a month of driving.
I am currently installing hydro assist and Red head box that showed up today. From what I've experienced personally and been told by many, with a Red Head box and a 2x8 big ass ram assist there won't be any death wobble lol..will report
 
The only thing i have found is the 2 in rams steering response a little slow. For mostly street driven i try to run a 1,5 ram to speed it up a little. But i run factory pumps on what i have installed. But you are on the right tract.
I made him aware it'll be a bit slow but he doesn't care about that. Thanks bud
 
He had these new 35s on the D30 for 4month before the swap and he said tires made a world of difference compared to old 35s so can't be the tires..thanks guys keep it coming lol.
Made a world of difference for what? Wobble? Sounds like a problem that was there before the swap.
 
For starters...give it some more caster. It's wandering back and forth. More caster will make it want to return to center and drive straight. Get it to at least 6° and I bet it drives totally different.

The steering box isn't supposed to actually "hold" it straight or keep it from oscillating. You could have a half turn of the steering wheel in either direction from center and you still shouldn't have death wobble.

And, as always, POST PICTURES. 90% of the time, if it's something blaringly obvious...it can be seen in a picture.

What's the setup on the panhard bar?
 
20240111_153817.jpg
 
or starters...give it some more caster. It's wandering back and forth. More caster will make it want to return to center and drive straight. Get it to at least 6° and I bet it drives totally different.
Really? If I give it anymore pinion will be pointing towards the ground lol..is that really a thing
 
How is the rear suspension? I assume it's all tight? Had several rear linked vehicles get what feels like death wobble caused by loose links
Yes it's all tight, 1.25 heim lowers and 7/8 uppers.
 
Made a world of difference for what? Wobble? Sounds like a problem that was there before the swap.
made a difference in how it rode..with his old 35s it rode rough..they were super old tires lol
 
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You can see the pinion is way up in that pic. That indicates your caster is way off. Set the caster to around 6* (this will lower the pinion angle). Report back.
Its parallel with frame/ground but I'll give it a shot, that's 2 for caster now
 
Wtf is this?
Started to mount the factory stabilizer but then stopped cause he started asking about hydro assist and stuff lol
 
With 5 degrees of caster, my pinion still has some upward angle to it. It'll be fine.
 
With 5 degrees of caster, my pinion still has some upward angle to it. It'll be fine.
How the heck? Mine is perfectly parallel with frame/ground and it reads 4.1....Ford tech told me to check it on the Tie rod knuckle...on top of the C right next to spring mount it reads 8.8 but on the Tie rod mount it reads 4.1... I'll double check again
 
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