Project Comanche Posted June 28, 2014 Share Posted June 28, 2014 A single pothole triggered it. I have experienced steering shimmy before, and this is most definately death wobble. Over the past few weeks I have read every article and post and forum on death wobble, learning many things while confirming others. It is a 1987 jeep comanche. Dana 30 front end on 35's. Trackbar and steering linkage similar to rustys offroad over the knuckle setup. It has a custom built long arm lift with radius upper arms. The kicker... I have had this truck for 8 months now. It has driven perfectly with no shimmy or wobble until now. I am at witts end trying to figure this out. I have never driven this truck with a steering stabilizer. I am not opposed to adding one but I am opposed to using one as a bandaide and not addressing the root of the problem. I have asked 5-6 different shops to look at it, getting different suggestions each time. Each and every one of their suggestions has been worked through by tightening, repairing or replacing. Many of the shops also recommended HD steering stabilizers and one shop even mentioned a triple HD setup. I took their advice while I countiued to scratch my head. Since the DW started I have fixed/replaced the following: Alloy USA upper and lower ball joints Tj style axle shafts (vac disco conversion) w/ spicer 460's Alignment checked out perfect(caster,camber, toe in, wheel bearings are tight, etc. @ gross and Stevens in Visalia) Tires balanced New dodge Durango steering box Plated steering box mount/unibody. (Two 1/4" plates with 1 1/2 round stock welded between and bored for mounting bolts) Super durometer poly bushings in trackbar Check tire pressure (28-30psi) Trackbar brackets checked out solid with zero movement Next is new heim joints even though the existing ones feel tight. Any and all advice is welcomed. I am ready to have a SAFE truck back on the road. Link to comment Share on other sites More sharing options...
Strokermjcomanche Posted June 28, 2014 Share Posted June 28, 2014 I know it's been discussed before but I don't feel a steering stabilizer is a bandage . They where on the truck from day one . Granted I wouldn't think the triple hd setup is what you need . It's like not having sway bar links , you can drive the truck but have someone pull out in front of you and you'll wish you had them . I'd say since you've gone overmostly everything put a stabilizer on it and go from there . Link to comment Share on other sites More sharing options...
zackcj7 Posted June 28, 2014 Share Posted June 28, 2014 I don't see control arm bushings/joints on your list. Have you checked them? I had Rusty's arms on my TJ and on two of them the bushings broke loose and shifted the arms so the were rubbing the control arm mounts. Needless to say the control arms rubbing the mounts caused some wicked vibrations. Link to comment Share on other sites More sharing options...
Jeep Driver Posted June 28, 2014 Share Posted June 28, 2014 CA bushings is my guess. Also......? my tires call for 50lbs You are running 35s that only call for 30lbs........>???????????????? Link to comment Share on other sites More sharing options...
Project Comanche Posted June 29, 2014 Author Share Posted June 29, 2014 I have checked the CA bushings. Upper control arms have brand new bushings and heim joints. Lowers have Johnny joints and bushings are in good shape. Checked on tire psi. Straight from Goodyear website it says 35 psi. Link to comment Share on other sites More sharing options...
Eagle Posted June 29, 2014 Share Posted June 29, 2014 Also......? my tires call for 50lbs I seriously doubt that 50 psi is the right tire pressure for anything under an MJ. The sidewall may say that 50 psi is the maximum pressure, but that's not typically the pressure you should run them at. IMHO death wobble=tire balance. Steering damper is to prevent steering wheel "kick-back" when off-roading. I've experienced death wobble in two Jeeps that had steering dampers, so I am quite certain that the damper will not cure -- or even mask -- death wobble. Link to comment Share on other sites More sharing options...
MancheKid86 Posted June 29, 2014 Share Posted June 29, 2014 it will mask d/w if the tires are somewhat balanced, i will also agree with you you can still have it with the stab on, because i have had it with the stab as well (my issue was glycol filled tires, that have been balanced, but up to speed dynamic balance was no there because of the offset in weight) theres nothing above stated about your rotors, my 40' tires will get d/w at 65 km/hr when the rotor is warped above or below is fine check em out? also, the tire shop can balance a tire, but if the tire has bulged, even though it is balanced, up to speed it can become dynamically unbalanced, and a bump can send it into an uncontrollable oscillation *EDITS* how is your track bar bracket to the frame? it likes to loosen and that causes loads of fun Link to comment Share on other sites More sharing options...
Jeep Driver Posted June 29, 2014 Share Posted June 29, 2014 Also......? my tires call for 50lbs I seriously doubt that 50 psi is the right tire pressure for anything under an MJ. The sidewall may say that 50 psi is the maximum pressure, but that's not typically the pressure you should run them at. IMHO death wobble=tire balance. Steering damper is to prevent steering wheel "kick-back" when off-roading. I've experienced death wobble in two Jeeps that had steering dampers, so I am quite certain that the damper will not cure -- or even mask -- death wobble. Cooper AT3, 48 in front and 42 in rear. Wear is even. 8" wheel. And the Gooyear Silent Armor before these......... Link to comment Share on other sites More sharing options...
comanchedude Posted June 30, 2014 Share Posted June 30, 2014 If all the suspension is good and tight. then rotate the tires to see if the problem goes away if so you have a tire that's out of balance, out of round, or damaged. the stabilizer will not stop DW. ( "death wobble") but it may help control it to some degree. As for MJ Junkie... a Jeep Comanche does not weigh enough to require 50psi tire pressure no mater what brand 35" tire you run. and its bad advise. Link to comment Share on other sites More sharing options...
Jeep Driver Posted June 30, 2014 Share Posted June 30, 2014 If all the suspension is good and tight. then rotate the tires to see if the problem goes away if so you have a tire that's out of balance, out of round, or damaged. the stabilizer will not stop DW. ( "death wobble") but it may help control it to some degree. As for MJ Junkie... a Jeep Comanche does not weigh enough to require 50psi tire pressure no mater what brand 35" tire you run. and its bad advise. Bad advise? Think not. He's running a 12" tire, he did not say what wheel or wheel width they are mounted to. A 12" tire should be mounted to a 10" wheel, otherwise at full pressure you pull up the tread as the sidewall expands out. To correct this, you guys reduce tire pressure. This causes lateral movement of the wheel inside the tire, IOWs the wheel is allowed to travel left to right inside the tire. Also causes some real slop and sway in turns. What width wheel are you using? Link to comment Share on other sites More sharing options...
Project Comanche Posted June 30, 2014 Author Share Posted June 30, 2014 15x10. Link to comment Share on other sites More sharing options...
Incommando Posted July 1, 2014 Share Posted July 1, 2014 If all the suspension is good and tight. then rotate the tires to see if the problem goes away if so you have a tire that's out of balance, out of round, or damaged. the stabilizer will not stop DW. ( "death wobble") but it may help control it to some degree. As for MJ Junkie... a Jeep Comanche does not weigh enough to require 50psi tire pressure no mater what brand 35" tire you run. and its bad advise. Bad advise? Think not. He's running a 12" tire, he did not say what wheel or wheel width they are mounted to. *A 12" tire should be mounted to a 10" wheel*, otherwise at full pressure you pull up the tread as the sidewall expands out. To correct this, you guys reduce tire pressure. This causes lateral movement of the wheel inside the tire, IOWs the wheel is allowed to travel left to right inside the tire. Also causes some real slop and sway in turns. What width wheel are you using? That 12/10 thing is way over simplified. It does not begin to consider sidewall aspect ratio for example. A quick check of tire sites lists a range of rim sizes for a given tire size not a " if the cross section is X then run only rim width Y " answer especially when looking at P-metric sizes. Even mentioning sidewall motion disproves that this "conventional wisdom" nugget applies equally to a 33-12.5-15 and a 315/45/20 despite their similar "widths." Link to comment Share on other sites More sharing options...
Project Comanche Posted July 23, 2014 Author Share Posted July 23, 2014 After much frustrating and weeks of giving up I found play in the pitman arm. Has anyone encountered this before? I have ordered a new one to see if this will solve the problem. I figure if I can see the play in the pitman arm when the truck is just parked then rolling down the road and hitting bumps makes this enough to initiate the death wobble. Link to comment Share on other sites More sharing options...
Eagle Posted July 23, 2014 Share Posted July 23, 2014 I know it's been discussed before but I don't feel a steering stabilizer is a bandage . They where on the truck from day one . But there weren't there to combat death wobble. They were there to prevent (or to alleviate) steering wheel "kick back" in off-road situations where the terrain grabs the front wheels. Link to comment Share on other sites More sharing options...
Strokermjcomanche Posted July 23, 2014 Share Posted July 23, 2014 . Link to comment Share on other sites More sharing options...
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