1999 GMC Yukon Build

noJeepshere

Adventurer
Question: I have a bit of death wobble, mostly when slowing down around 30-40 mph, and it wanders some as well. I know all the steering joints are nice and tight. On Monday I took it to my mechanic to get the speedo recalibrated, and I asked him about it, and he suggested a track bar (Panhard bar) His reasoning is that a crossover setup is very sensitive to any movement of the axle sideways and a track bar will prevent that movement, thus eliminating the death wobble and wanderiness. What is everyone's thought on that?

Also, the springs have settled down quite a bit, but they're still stiffer than the rears, and hopefully they get softer still. It sits nearly level now, even without a zero rate in the back. I'm still going to put one in though.

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noJeepshere

Adventurer
Also, the 315's I originally went with were just too big for my liking, so I went down to some 295's, Hankook Dynapro's. With my old setup, (265's with 3.73 gears) I was doing 2,000 rpm at 70 mph, now with 295's and 4.56 gears I'm turning 2,300 rpm at 70. Not bad, definitely has more getup than before, but still too soon to know how badly fuel economy will be affected.
 

chilliwak

Expedition Leader
NoJeep my experience is as following...

1 The truck will handle awesome offroad, but not on the pavement.
2 The truck will handle awesome on the road but lack articultion offroad.
3 Sugestion. Swaybar up front with quick disconect.
4 I had to go rear sway bar in combo with front sway bar to handle my camper on the 79 Chev pickup but I am sure you are fine with front swaybar.
5 I am using no sway bar and have just learned to get used th the aproach to death woble and stay out of the zone. I am even driving a short wheelbase sas Yukon!:Wow1:
 

justcuz

Explorer
The big thing about death wobble is its a harmonic situation that causes the tie rod to be a tuning fork. Steering dampeners and trac bars are band aids and add more links to go bad. I would check your caster angle and possibly sleeve your tie rod before adding a track bar/panhard rod. I know you had the front end rebuilt, were the tie rod ends replaced? If it's happening under braking only you may be getting slight toe out under braking force. Toe out induces wobble also, maybe try a little more toe in.
Toe out will also cause it to wander. The off set of the wheels also contribute to the tires wanting to toe out if the are positive off set (wider outside than inside). I would add another 1/16 or 1/8 of toe in and see what happens, before anything else.

Your truck turned out beautiful, how was the Moab trip?
 
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noJeepshere

Adventurer
I actually didn't go to Moab, my grandma passed away that weekend so I stayed home to be with all my family that came in from out of state. But I'm planning a trip there with my friend in his stock Tacoma near the end of October.

And:

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I know I know, driveway poser pic, but daaang does it look good! :ylsmoke:

cent frum a smaert fone
 

11MPG

New member
Sorry to hear about your grandma. Hope the family is doing well.

For death wobble build a mount on top of the passenger side leaf ubolts and run the panhard bar to the frame on the drivers side. 3/4 heims would be bullet proof. Throw on a steering stabilizer and your done. Guys have been doing this to K5s and K10s for years. Big tires make em loose.
 

chilliwak

Expedition Leader
I too am sorry to hear about your loss. I hope you mare doing ok.
The truck looks wicked. Nice ride and welcome to SAS world! Cheers, Chilli....:wings:
 

Chevrolado

Cruisin'
Sorry buddy. :( praying for you and the fam.
That being said.. Please, post all the pics you want of this rig. I think I speak for many when I say we always love seein it. Hah. :D
 

noJeepshere

Adventurer
Thanks for the well wishes guys, it was a good thing for grandma to go, she missed grandpa all the time since he passed 5 years ago.

And Dave, hopefully there will be many pictures of the Green Giant (my nephew renamed it for me)

cent frum a smaert fone
 

justcuz

Explorer
Just lost a elderly family member too, sad to see them go. Hope your family is adjusting well.

Again to reiterate the panhard rod and steering stabilizer.
A panhard rod will move the axle side to side as the axle moves up and down. This will side load the springs and bind the suspension as it travels up and down, making your ride stiffer. The steering stabilizer is a horizontal shock absorber that will only mask, but not fix your death wobble. This is why I call them band aids.
Go to Allpar.com and look up death wobble. It explains it completely.
Correct toe in, caster and steering axis inclination are the fixes for the problem. The fix may not be textbook, or in the service manual, you may have to play with it a little. I would start with increased toe 1/16th at a time.
 
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noJeepshere

Adventurer
Thanks for the input, I'm going to wait a bit on new king pins and having the alignment done until I can get new rotors. Then, I'll set it to 88 Ford F350 specs, since that is what the axle came out of.

cent frum a smaert fone
 

chilliwak

Expedition Leader
Thanks for the input, I'm going to wait a bit on new king pins and having the alignment done until I can get new rotors. Then, I'll set it to 88 Ford F350 specs, since that is what the axle came out of.

cent frum a smaert fone

Be carefull that you dont jinx it with Fraud settings.....:Wow1:
 

noJeepshere

Adventurer
Installed some ORD zero rate add-a-leaves to bring up the rear, didn't quite make it sit a touch higher than the front, dang.

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Gonna need some new u-bolts...

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cent frum a smaert fone
 

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