crossmember reinforcement/more clearance mod

[Kejtar]

OK, I know (or rather I was told) that some have modified their stock crosmember to have more clearance and they also strengthened it... any pics? instructions? I have two slightly bent ones to experiment with ... and I can always go to a pick a part to get one

Thanks
Kejtar

 

[BrettM]

seems to me it would be just as easy or easier to just make a whole new one. that's what I plan to do soon.

 

[2xtreme]

It was my impression (not my experience yet) that if you run a piece of flat bar (you pick the thickness) strait across from the two rails then you get a flat cross member (flush with the frame rails) and the transfer case will not be dropped from stock, you just need to drill a couple of mounting holes and transfer case mounting holes.

I think when I do it, I would make it wide enought to provide more skid protection also.

Sorry I can not be more helpfull.
Michael

 

[RCP Phx]

Flat stock isnt strong enough!

 

[Cresso]

Any proof that flat stock isn't strong enough?

 

[RCP Phx]

Probably nothing that would satify you.But I have been fabbing custom parts for over 30 years and I can tell you that I can bend 1/2"x4" flat at that width with no tools.With that size your also talking about a 20lb crossmember.

 

[XJZ]

Flat stock will bow (but maybe with all that flex you won't need a tranny bushing ).

I don't think you can get the x-member perfectly flush because the t-case will hit the tunnel, there's just not enough room up there. Plus you'll have to address a higher rear driveline angle (of course the front angle would be less). Depending on how high you have to jack the t-case to get the member flush, could also have an effect on the fan blade/radiator relationship.

But there's always a way if you really want to do it. Depends on how much time and energy you want to put into it.

Goatman has a modified crossmember that sits more flush than stock, without dealing with all the other issues of a totally flush x-member. You might want to check his site.

 

[RCP Phx]

1"x4" is the perfect stuff,gives you 1" more clearance!

 

[Cresso]

I don't doubt that a flat crossmember will flex. How bout any flat stock crossmember failures?

Also, does anyone know how much weight the crossmember does support when sitting still (obviously, the weight it must be capable of supporting is much greater when going over bumps or dips)? I would've estimated somewhere around 100lbs or so....I know I can support it by myself, but I sure wouldn't want to lift it from the garage floor.

 

[RCP Phx]

Ok,now land a 4000lb jeep on it!You also just changed the nature of the loading on the frame rails.Instead of a vertical loading it now becomes a horizontal loading pulling on the frame rails!Plus your driveshaft is gonna luv you,LOL!

 

[XJZ]

Ok,now land a 4000lb jeep on it!

Exactly....what do you do when your XJ is highcentered on the x-member? Your t-case will be coming up through the floor.

 

[Cresso]

Good idea, but it didn't answer either of my questions. =)

 

[Kejtar]

wait.... Goatman has a website? Got a link? IT was his crossmember that I was told about...

Kejtar

 

[forgiven]

I started with a piece of 1/2x6 bar stock flexes under the weight of the Jeep, I tried it. Then I reinforced the back edge with 2x2 angle iron. No mo flexo. After all that work I still had to use a 1" spacer between the cross member and the "frame" to make room for the t-case. I believe I gained about 1.5" of clearance and I'm sure this crossmember will not bend. I then fabbed skids that attach to the and rear of the CM.

 

[HossHoffer]

Mounts

Hey RCP PHX, What kind of mounts did you use and where did they go. I'm going to fab one like your picture but just wanted to know if you used the OEM type tranny mounts.

 

[RCP Phx]

I started with a piece of 1/2x6 bar stock flexes under the weight of the Jeep, I tried it. Then I reinforced the back edge with 2x2 angle iron. No mo flexo. After all that work I still had to use a 1" spacer between the cross member and the "frame" to make room for the t-case. I believe I gained about 1.5" of clearance and I'm sure this crossmember will not bend. I then fabbed skids that attach to the and rear of the CM.

"Holy smokes Batman",now were talking about a 40lb crossmember!

Yeah mine uses the stock mounts,I just added a littlte drop because of my lift height!

 

[FatXJ]

It's all in the design. A piece of flat stock will bend no matter how thick. Now if you add ribs (perpendicular steel supports) to the face of the stock then the ability of it to flex is eliminated.

Basically make it 2 dimensional and you're all set.

 

[vintagespeed]

Any proof that flat stock isn't strong enough?

Sure, take your ruler that you drawing up that custom suspension with and grab it at the ends. Now flex it in the middle. That's what your crossmember is going to do.

 

[XJZ]

Kejtar....not really a site (sorry)...online photo album. hoto: ..I believe the photos are in there somewhere...

http://fototime.com/ftweb/bin/ft.dll/home?inv=383E99C5633A988

 

[Bent]

Even us Carpenters know that flat anything is nowhere near as ridgid as that flat anything with at least one "sheer panel". About the only way to reduce flex in a flat pc. of stock would be to "laminate" more than one layer one on top of the other(s). At best, this provides wery limited results until the thickness begins to approach the width. Think of the second or perpendicular surface as kinda like a gusset. The thicker stock at the horiz. surface does resist crushing better than thin does. Hovever it is the vert. areas that helps even the stock sheet metal cross member resist the amount abuse that they do. Think about this, when was the last time anyone has seen a bridge that was only a single horizontal ribbon with no other vertical supports of any kind?