mmccurdy

I recently installed a Body Armor rear bumper, and it came with a 2" hitch receiver. So I removed my factory receiver to make room for it. But there was a sticker on the bumper saying it should be used for recovery only -- presumably that means not for towing purposes? Is this a real concern, or is it more a CYA move on the part of Body Armor? I'd like to be able to tow things up to the rated 3500 lbs, so I'm thinking of grinding off the Body Armor hitch and putting the factory one back on.

FWIW, the four substantial bolts through the frame member on the factory receiver do seem a bit stronger than the setup on the new bumper. Basically, the welds holding the new receiver to the new bumper seem sound, but the entire setup is held on by four bolts in oversized holes in the factory frame rails, and I've already had to "re-align" the setup due to them slipping a bit.

wayoflife

Hmmm, that seems odd especially considering the fact that the forces being placed on a recover point can well exceed the entire weight of your Jeep especially if you are involved in a difficult pull. Need I say, that would be WAY more than 3,500 lbs. Does the receiver have a safety chain point? If not, that might be the reason for their warning or, perhaps it's just a way to get out of any liability issues. Either way, if this hitch is designed to withstand the forces of a recovery pull, I would definitely think it can be used for towing as well.

mmccurdy

Yeah, that was my logic as well. It does have safety chain points -- which obviously wouldn't be needed for recovery purposes, and part of the reason I found the warning surprising and strange. I don't have any pics of mine yet, but you can see the hitch setup here, complete with warning sticker:

http://www.project-jk.com/wp-gallery...2_itemId=25688

:confused:

nycauburn

i am sure it is the old CYA, it probably cost a little more to be certified for class 2 or 3 or whatever it is. so why not just give the old CYA disclaimer. i tow with my tj with the warn bumper all the time and it is the same disclaimer. no wear or problems yet on it. o would not worry a bit

adaycj

If things are slipping there is not enough clamping force or not enough area with enough clamping force.

Look up the hardware in a book (like the ACE handbook from the hardware store) and torque the bolts to the max spec allowed with dry threads. Eliminate lock washers and use another locking method to help (lock washers suck). If there is still slipping I would not tow or recover with it until it is solved. Putting the bolts in shear will cause them to fail.

You could use larger hardware, or more bolts to increase clamping force too, as long as other compromises can be avoided.

I also think that towing should work, but not until the slipping is fixed.

mmccurdy

Yeah that's a really good idea -- I didn't realize you could get general torque specs from that book, so I'll definitely do that. None were included with the bumper (instructions just say "torque them down.") I don't really see what the lockwashers add either. I'll give this a shot.

mcnaught6

does anyone know if the LoD rear bumper has safety chain points? i have looked at all the pictures of them i could find, but haven't seen the safety chain points on any of them.

if they aren't on there, what is the point in having a towing receiver if there aren't any points to secure safety chains?

flyer415

I was planning on buying the LOD bumper and I never even thought about the safety chain points. Anybody out there actually have the LOD bumper.

Guess I could always get some welded on.

EDIT: Just sent an email of to LOD and 4X4explor to ask.

adaycj

Wow, no torque specs and lock washers. Sorry to hear the company that made that thing couldn't help its customers be safe.

As a whole a critical interface should never include a split/lock washer. Obviously many did in the past, but it does not inspire confidence in the engineering of the part that in 2007 they are still included. I hope the size and grade of the bolts are ok for recovery and towing.

I have a personal distaste for lock washers. Split washer type locking washers try to lock the fastener by digging into the face of the nut and mating surface. They damage the nut any time the fastener is moved in the loosen direction. They can also be smashed out from over torquing or impact. They do not function properly (for locking) when a flat washer is used to protect the mating surface or the nut.

This is one of my favorite conversations about lock washers

http://www.***eng-tips.com/viewthrea...=114051&page=9

Please take out the *** as I am attempting to avoid a linking to a "for pay" web site, even if it is not Jeep related.

mmccurdy

Man awesome link... thanks.

FWIW, the bumper hasn't actually slipped under normal use since I torqued the crap out of them, but hooking up 3,500 lbs. worth of trailer might stress things just a tad more. In any case, I guess I'll need to get rid of these creations of the Devil they call lock washers

I've always been a little skeptical that some tiny amount of lateral force near the split in the washer would do squat (let alone actually dig in) when the thing was torqued down to 125 ft-lbs. But they seem prevalent, and I'm no engineer, so what do I know?

So the question is what do I put in their place -- should I just go with some blue Loctite? In my application they're sizable bolts (5/8"?), and the back side goes into a nut that's welded to the bumper.

Way off topic: wtf is the difference between "red" and "blue" thread adhesive anyway?