steering shudder/death wobble

[tugalo]

Been driving my 88 MJ for several years with a shuddervibration in the steering and if i drop the left front into any kind of road depression the truck goes into death wobble.  Took it to a shop today to see if they could align it and hopefully find what was loose in the front end.  They just called me and said that the frame was cracked near the steering box.  Anyone run into this before?  Any precautions to take before I have it re-enforced/welded up?

[Eagle]

It hasn't happened to me, but there have been reports of the frame cracking at the steering box in both MJs and XJs. There are aftermarket parts to brace the steering box, and kits to plate the frame in that area for extra strength.

 

What size tires do you run, how much rock crawling do you do, and how often do you turn the steering wheel when the vehicle isn't rolling?

 

[JMO413]

https://mountainoffroad.com/products/steering-brace-87-01-xj

 

I have this one on mine.

 

There all a ton of options out there for stiffners and reinforcement of you search for an XJ.

[Smokeyyank]

Happened to me on my XJ. Only way to fix permanently it is put stiffners on and have that area fully boxed. A company called cRok used to make an entire system that fixed it but I don't think they do anymore. Looks like jcr might have something close. 

 

https://www.jcroffroad.com/product/XJUNF-PC.html?gclid=Cj0KCQiAkZKNBhDiARIsAPsk0WiJmFMsgUxp-afsUtU1tt1GFGyc8up6wMdaIAQTApqBTQnkTqt-pVoaAprGEALw_wcB

 

 

[75sv1]

Happened to me too. I was having fits with DW. Tried a bunch of stuff. It was ripping off my OTK trackbar. Finally cleaned off the grease and saw it. Mine is just some welds on there. I would agree that some frame stiffeners would be a good idea. On my next and present builds I put some frame stiffeners on. Actually it started that the rear frame was rusted out on the bottom. I put Hooligans on the rear, IRO on the mid, and Ruff Stuff on the front. My next build, I have Hooligans, mid and front, and IRO rear. I don't know if I'll change the IRO rears. They are 10 ga. Hooligans are 3/16. I also, used T&M inner stiffeners. It would also, depend on what your build is. If stock, then the 10 ga would be more than fine. Plenty of choices in frame stiffeners.

I do have steering box braces on both of my builds. The MORE posted would be good. There are others, more robust. Ironman and Boostwerks. $$$ though. Also, replace the gear box spacer with steel one. 

XJ – Hooligan Off Road

[AZJeff]

I went through this issue as well, as a previous owner had done a half-a##ed job of repairing cracks caused by some super-swamper tires that were on the machine when I got it..  

 

You should be aware that the MJ/XJ steering box attachment is designed to "just barely" work with stock tires and stock ride height.  Changing any of that will stress the frame where the steering box mounts to the point where cracking is a potential.  The chances will increase if you do things like rock crawling.

 

Part of the reason the "frame" cracks around the steering box is because the OEM GM/Saginaw box is only mounted with three bolts.  Most recirculating ball boxes use four bolts, and that spreads the load on the frame against four points rather than three, lessening the load on each mounting bolt.  Four-bolt Saginaw boxes CAN be installed, but it's a lenthy project, and unless you are doing serious off-roading with big tires, it's easier to just bolster the mounting of the three-bolt OEM box.

 

The best thing to do is the following things to resolve your issue, even if you don't plan on doing any of the things I described above that can increase the risk of cracking:

 

1.  ditch the OEM steering box spacer bracket that is made of cast aluminum, and install a steel steering box spacer.  There are tons of suppliers for this part, and it helps to distribute the forces on the "frame" over a larger area.

2.  increase the thickness of the outside (wheel side) surface of the frame.  Some guys weld-in a reinforcing plate, but a good bolt-in plate will do the job if it's thick enough.  I extended by RockHard bumper mounting flanges rearward to cover all three bolts for my box.  The bumper flange was about 3/16" thick, so adding that layer over the relatively thin "frame" rail wall (that is probably only 1/16 or 3/32 thick) will considerably bolster that outer wall.  

3.  Use hardened washers under longer grade 8 bolts to attach the steering box.  It will spread the clamping force out better on whatever you do to reinforce the outside wall of the "frame"

 

There are two types of cracks that can occur in the MJ/XJ steering box area of the frame:

 

1.   those that  radiate out some distance from the mounting bolt holes.   These can probably be addressed effectively by the steps I outlined above.

2.  If the frame cracks are in the top or bottom surfaces of the "frame" rail, the cracks should be welded, and doubler plates should be welded over the repaired crack.  Such cracks will NOT stop when the steering box mounting is repaired, and will continue to get worse.  These types of cracks MUST be repaired via welding, as any of the three steps I described above won't really do much, if anything to stop the crack once it has started.