Ok. I replaced my steering box in november after breaking all three bolts and losing my ability to steer completely. I have not driven offroad since because of wyoming winter. I went offroad yesterday for the first time this season on a rough but not too bad trail and I broke the bottom right bolt in my replaced steering box. Broke off right in the middle of the box. My steering wheel was cocked all the way left. Why do I keep breaking these bolts??? I dont understand how this keeps happening as soon as I drive over a rock a steering box bolt breaks. If I cannot get this problem resolved I will put a grenade in my steering box and call allstate. THank you .

 

It sounds like you are using crappy low grade bolts. Try using some good grade 8 bolt and hopefully that will take care of your problem.

 

They are grade 8.

 

WOW! And they still keep snapping? How does it steer before the bolts snap? Does it feel like it's binding or anything? Does it look like everything is going in straight and not a little cockeyed? I'm just trying to figure out what would cause them to keep snapping. Hopefully some one that has had this happen to them will chime in and give there input. I will be fallowing this one. Hopefully it will be something that you can take care of easily.

 

I call BS. Either you are not using the correct length bolts or they are not *good grade 8 bolts.

It takes 13680 pounds force to shear a 7/16 grade 8 bolt. I know there a lot of force on a steering box, but I don't believe you're putting 15k pounds of force into.

 

I get a little bit of binding when I turn the wheels hard. I think It is because Im in 4 part time tho. The bolts are in straight. It all started when I put an aftermarket bumper on. Bolts kept backing on and breaking so I replaced the steering box thinking it was faulty. Everything was fine driving this winter. First time offroad and a bolt breaks. Im afraid when I drill it out and replace it the treads are going to get stripped and that same bolt will keep backing out or breaking and Ill be back to square one needing another box.

 

Could this have something to do with the aluminum spacer? Maybe lack of alignment? I know what bolts I used. Im looking for what is causing them to break. Thanks.

 

OEM Bolts, part number 6035939AA, MSRP $4.85 each

OEM Washers (special), part number j4003926, MSRP $4.60 each.

Bolt torque 70 ft./lbs. (dry - no lube or anti-seize)

 

So i just got the bolt out. Hammering a 10mm wrench onto the threaded end and backing it out worked well. Just replaced with a 7/16 4 1/2 inch GRADE 8 bolt. No one has had these bolts break like this before? Hard to believe.

 

No I honestly don't know of anyone who has broken a legit grade 8 bolt like that. And I still dont believe that it was grade 8 in the first place or you have some serious issues going on.

Do you have a steering box spacer (aka reinforcer) plate?

http://c-rok4x4.com/Products-SteeringBox.html

 

I snapped the bolts off of my stock box when I did the Durango upgrade.

Are you still running a stock box? If you have a Durango box you need the washer spacers to keep the box from binding.

 

This is very strange, I've been running smaller 3/8" diameter grade 8 bolts like a fool because i stripped out my steering box threads and I have had any break. Make sure they are all in there straight and the box is seated properly. If any individual bolt is experiencing more of the load the bolt can break, which in turn overloads the others.

 

Make sure the hardware you are getting is of good quality. A real grade 8 bolt can be identified by the 6 marks on the top of the bolt, Grade 5 has only 3 marks, grade 2 usually has no markings. It is pretty difficult to break grade 8 hardware but not impossible... Make sure you are torquing the hardware to the correct specification.

 

This is what I was thinking, that's why I was asking if it felt like it was binding. I'm glad to know that someone has had a similar problem. I have snapped some before on a Nissan 4x4 that I owned many, many years ago. But, I did it when I was young and stupid and I was running my Nissan way to hard and snapped them off. I was running 36" tires and getting it air born and did it one to many time

 

Just because they're SAE8 doesn't mean they're any damned good - it's been a hard rule for me that anything that might be from China is to be considered "counterfeit" if it's marked more than SAE Grade 2 or ISO PC 4.8.

Outside of overstressing (which is caused by bad parts selection,) there are two primary failure reasons for threaded fasteners:
- Counterfeit parts. They're marked as being of a certain strength, but the reality is nowhere near specification. Chinese screws are automatically to be considered "counterfeit" (based on my own experience - threaded a 5/16"-18 screw into an iron casting should not cause the screw to fail at 20lb-ft applied torque!) and parts suspected of being from China should be suspected of being counterfeit. Chinese feedstock may be mostly US scrap, but they can't heat-treat worth a damn (it is interesting to note that I know several Chinese engineers over here who feel the same way, so it's not just me.)
- Improper installation. For critical applications (suspension, steering, engine internals, et al,) proper preload allows for elastic deformation to retain the screw, and the proper tensile preload allows the screw to handle increased tensile stress/strain. If the screw "bottoms out" (blind holes) or is allowed to work loose until there is no tensile strain on it, working forces can cause premature failure - generally by rupture of the screw, and parts falling off!

Get known good screws (or screws of known provenance. China-source should be avoided. Taiwan, Hong Kong, Japan, US, Canada, and nearly anything European is acceptable,) and ensure that they are being installed properly and the threads are being retained (LocTite, locknuts, or deformed threads will all serve. If you use a locknut on a through hole without a spec, installation torque on the nut should be at least 75% of the spec for the screw, and the screw should be long enough that you have full thread engagement with the nut finger tight - with 1-2 threads sticking out past the face of the nut.)