Crossmember mounts

[ZacSquatch]

My crossmember is 2x4", 1/4" wall rec tube... It is notched on the middle for a lower tranny mount as well the mounts where it bolts to the frame rails. This puts it 1/2" below the frame rail and still drops the tc 3/4". I'm welding it to a peice of angle and running it along the frame rails to bolt on with 5 bolts on the bottum and along the sides.

Now, I'm going to install TnT stiffeners, and I though about drilling 3/4" holes into the stock frame rails, and then welding 1/2" nuts to the Stiffeners to bolt the crossmember angle too... The nuts will fit in the 3/4" holes.

Anyone see any issues to this? I'm plug welding and stitch welding the TnT's on so I thought they's be plenty strong to have my crossmember bolted to them.

 

[TRAILREADYXJ]

Is your crossmember just that, or are you using it for CAs as well?
How many bolts are you planning to use?
Will the crossmember be mounted in a single or double plane?

You could also weld a plate to the stiffeners there for extra reinforcement while you're at it.

I am planning a similar setup, but will be using 1/4" angle to brace this section of the frame instead, something similar to Vetteboys.

 

[ZacSquatch]

It will be used as CA mounts as well..

Bolted from the side and bottum, 2 planes.. and I plan 5 on each plane, so thats 20 bolts total, 10 on each side.

 

[TRAILREADYXJ]

I'd say that should be fine, especially if you bolt through the frame ,on the side, with sleeves and backing plates.

 

[ZacSquatch]

Thats what i was trying to eliminate haveing to do though, the sleeves... Just nuts welded on the inside of the stiffeners

 

[XJEEPER]

Thats what i was trying to eliminate haveing to do though, the sleeves... Just nuts welded on the inside of the stiffeners

Why? Seems like you can just leave out the backing plates because, as I picture in my mind your crossmember fab explaination, the angle welded to your crossmember will accomplish the same purpose as backing plates when you run a bolt through the unirail.

To overstate the obvious.......the sleeves are aptly named, anti-crush sleeves, which when used in this application, will keep your unirail from collapsing/deforming when the bolts are tightened down.

Will your idea work? Probably. Negative long term side effects of leaving out the anti-crush sleeves?...... :dunno:

I'd just install them for added strength and reinforcement and forget about it..................

 

[ZacSquatch]

NOOOOO..

The bolts will NOT run all the way through the fame rails...

Map Key..
Black= fraim rail
Red = unibody stiffeners
Blue = nuts
Teal = angle for crossmember mount..

the nuts are welded to the unibody stiffeners... and the nuts fit into holes cut into the unibody rails.. Then the angle has holes to allow bolts to sandwitch them to the stiffeners.

 

[XJ_ranger]

ive always been a fan of thru bolting things - so I can get a locknut on the other side...

Ive had to tap out my OEM 4 crossmember bolt holes more times than i have wanted to because I stripped a bolt or whatever, and had to fix my problem...

Id hesitate to commit to blind nuts welded to the frame...

also when welding nuts which are generally plated in Zinc, the weld kinda sucks, and generally doesnt bond as well to the nut, and then you end up tightening your crossmember bolt till you hear a 'pop' and it get REALLY easy to turn, and now you have a bolt that you cant get out...

do what you will, but make sure im in front of you on the trail when your t-case needs to be removed...

 

[WheelinJR]

The welded on nuts seem like a decent enough idea, I think it will work out well for you. I dunno if 20 attachment points is so necessary, I'd think more like 6 per side would be sufficient enough and then some.