Rear Crossmember Replacement Poll Time

[Dork]

Hey

This has probably been discussed before, but searching hasn't found me anything specific. I'm coming up with ideas for building a new rear bumper, and am contemplating removing the rear crossmember in order to make something fit a bit more snug. Bumper will likely end up being 3/16" plate, with 3/8" frame attachment plates that also form recovery points. Receiver in the middle, supported from the back with a piece of 2x2 spanning between the frame rails. Here's my question:

After removing the crossmember, would a person prefer to weld a chunk of 2x2 or similar in between the frame itself, and bolt the receiver to that, or rely on the bolted-in bumper with the chunk of 2x2 in between frame mounts for structural integrity?

 

[mudgudgeon]

I did similar and welded it in, and made with some 3/8 plate brackets welded to the bumper/ new crossmember that slipped 8" into the frame and were plug welded in several places.
It's not going anywhere.

In my state, the bureaucracy decree that a tow bar has to be bolted to the frame, cannot be welded. If I added a receiver to mine, it would be even more illegal than it is already

 

[Hornd]

If Tow Hitches have to be welded to a frame than any hitch on a Unibody car is illegal including my Lexus RX.

 

[Heckraiser]

I don't think it matters if it's welded or bolted, as long as it's designed with enough strength. Your recipe sounds pretty good either way.

 

[chap79]

I removed the factory cross member for my bumper. Mine is very similar to what you are suggesting, 3/16' skin with 3/8" tied to the frame with another 3/8' fish plated to that one to form the recovery points. What I did do is put a piece of 2x2 across the top inside of my bumper which the receiver mount is welder to and the 3/16 skin covers it all. Essentially a tow hitch integrated inside the bumper itself. If that makes sense...

 

[shocktower]

Look at 4x4 labs, their bumper kit, has you removing the rear cross member, I hope to do mine soon

 

[shocktower]

I did similar and welded it in, and made with some 3/8 plate brackets welded to the bumper/ new crossmember that slipped 8" into the frame and were plug welded in several places.
It's not going anywhere.

In my state, the bureaucracy decree that a tow bar has to be bolted to the frame, cannot be welded. If I added a receiver to mine, it would be even more illegal than it is already

Oh you rebels on that prison island

 

[Fj81]

I am all for bolt on solutions. My last three aluminum trailers for my 18 wheeler were all fastened together with bolts or rivets. My current one has a load weight rating of 100,000 lbs spread out on the deck! I never used it for that much but its there. I know its an oddball example, but if it works fine for commercial equipment, it should be fine for small vehicles too.

Besides, it makes replacing a damaged rear end a piece of cake, or if you deside to change up or modify your work you can remove it and reattach it after you work on it. Or after its all built how you like you can then burn it on.

 

[baldilocks]

Bolts are more time consuming and expensive than welding. The factory cross member was welded in wasn't it. You could incorporate your receiver into the new bumper and design it to be a bolt in unit. I see the cross member as a permanent structure.

 

[Malleus]

I did similar and welded it in, and made with some 3/8 plate brackets welded to the bumper/ new crossmember that slipped 8" into the frame and were plug welded in several places.
It's not going anywhere.

In my state, the bureaucracy decree that a tow bar has to be bolted to the frame, cannot be welded. If I added a receiver to mine, it would be even more illegal than it is already

The thinking is that welds are nearly impossible to guarantee, but bolts, which come from inspected manufactured lots are more likely to be consistently acceptable (providing, of course some idiot doesn't pick the wrong size bolt). IMHO, either method would work well. Bolting in allows for easier removal, but like the man said, "Why would I want to pull out after putting in all the work to get in?"

 

[mudgudgeon]

Oh you rebels on that prison island

I know. On occasions I'll fit 35s to it too!

I'd be flogged in the town square if they knew I had such flagrant disregard for public safety

 

[Dork]

So, its basically close to one of those 50/50 split opinion kinda things, eh?

Mixture of both it is i guess. Weld in a cross member so that its a solid permanent part of structure, and bolt the receiver/bumper to it along with the frame so its easily removable if need be.

Thanks

 

[richardlillard1]

I'll second (or third, or fourth, or whatever) the 4x4 labs bumper. Pretty solid design that, with a couple tweaks, works really well.

If you intend to actually wheel the rig, gussets along the bottom will go a long way and asking him to make you a kit in 1/4" instead of 3/16" will go even further. If I had done the latter and it might not have such big dents in the side wings.

But whatever, that's under the truck anyway.

 

[Sarmajor]

I chopped the rear cross member out of my truck to fit the 4X4 Labs rear bar. No hesitation at all. The rear frame members don't really do anything that far back except hold up the rear corners of the body and give a point to attach the towbar.
All the suspension inputs to the chassis are well forward of the rear cross member.
Seeing as the 4X4 bar combined a replacement cross member and a tow hitch in one thing I was ok with it.

I say bolt it in.

 

[Hornd]

I know. On occasions I'll fit 35s to it too!

I'd be flogged in the town square if they knew I had such flagrant disregard for public safety

**1936 Last US Public Hanging....now they kill on Facebook instead

 

[Mandrake]

Bump It Offroad's high clearance rear bumper requires xmember removal and bolts in using the six trailer hitch bolts. I'd have to say that this is pretty close to how most aftermarket rear bumpers attach, and considering the bumper is orders of magnitude stronger than the 16 gauge stamped steel xmember, is an improvement.

 

[Redgrrr]

My biggest complaint with the aftermarket bumpers is the weight...The question I asked myself before I started was do I need to carry a bunch of stuff on the back bumper or would it be better to chop and clearance for wheelin. I chose light weight. I never weighed it all but this was dang close to the amount of weight I cut off.

For a camping/expedition truck. 4x4 labs and the Bio bumpers are the cleanest IMO. I tend to Beat on my cruisers so 2-4K for a bumper is not gonna happen...I prob have $200 tops and two full days in this one.

 

[chap79]

If I didn't have to drive a few hours to be able to camp and wheel I would have taken a "lighter" approach to my build. But at that point I'd be in a truggy.

I'm still the boat to integrate the cross member into the bumper and bolt it on. Don't weld or bolt in something that will just get in your way later if you decided to add an aux fuel cell, under car storage, or midget smuggling compartment.

 

[LandCruisinMy93]

Something similar to this
My 3 linked daily driver build thread post #85
But with some 3/8 recovery points?
I ended up leaving the factory recovery points when I built both of my bumpers. I couldn't think of a great way to integrate them that would make them a rated point at the time without having them welded to the bumper body and bolted to the frame. My rear has undergone a few refinements since I originally built it and will probably go through some more.

 

[Dork]

Something similar to this
My 3 linked daily driver build thread post #85
But with some 3/8 recovery points?
I ended up leaving the factory recovery points when I built both of my bumpers. I couldn't think of a great way to integrate them that would make them a rated point at the time without having them welded to the bumper body and bolted to the frame. My rear has undergone a few refinements since I originally built it and will probably go through some more.

Yeah, real similar i guess. I think I'm going to be putting the truck side bracing for the reciever to be permanent on the truck, but bolt the reciever to it so that if i ever pull the bumper off for whatever strange reason i can still drive. Bumper, with attached welded reciever would then bolt to the frame directly and back of the reciever bolt to the new cross member.

I got the plan in my head, words just don't get the idea across.