Rear Cross Member Replacement - Body On

CJ7Pilot

18436572
LIFETIME
CJ-8.com Member
City
Yuba City
State
CA
#1
When I bought my Scrambler, the rear cross member was pretty mangled... the PO had clearly tried a few different towing/pulling methods, before having a good receiver mount welded to the frame.

crossmember - 1.jpg

Since I've had this Jeep, my friends have been telling me the receiver was welded on crooked, but I've always maintained the opinion that the mangled cross member just made it look that way... now, we shall see....

crossmember - 2.jpg

Yep, the receiver looks pretty straight! I used a plasma cutter and a saws-all to cut off the old cross member. In most cases, a saws-all would do the whole job, but that receiver mount cross piece got in my way. Also, note that the bottom mounting points inside the frame rails are jacked. The left side has pulled through, and the right side has a bolt broken off inside... both sides are pretty deformed.

crossmember - 3.jpg

Here you can see how badly the bottom of the left frame rail is deformed. I tried pounding it flat with a 2-lb sledge, but it wouldn't budge. I'll probably cut most of it out, and weld in a patch... or I might skip the patch, since the new cross-member will cover that area anyway. You can also see both cross pieces for the receiver mount. The closer one is 2x2x1/4 angle, welded between the frame rails. The other (toward the front of the vehicle), is 3x3x1/4 angle, welded to the bottom of the frame (I'll round those corners during this project). As you can see, there's plenty of structural support here, that almost negates the necessity of a rear cross member (aside from bumper mounting).

crossmember - 4.jpg

Here's how the receiver mount all goes together. It's not quite how I would have done it, but it's plenty sturdy, so I don't intend to change it (for now).

crossmember - 5.jpg

So knowing that I'd be tackling this project sooner or later, I bought a ChiefWaho rear cross member a couple of years ago. I'm so happy to finally be getting around to installing it! In the photo above, it's just hanging in place. I can't push it all the way on to the frame rails, because of the deformed lower bolt holes.

crossmember - 6.jpg

Here's the problem I'm dealing with. I could grind the lower edge of the frame rail flush, but since the deformity is deeper than the thickness of the metal, I'd be removing most of the metal from that area. That's why I think I'm just going to cut it out. 20 seconds with the plasma cutter vs 10 minutes with the grinder... yep, I think that's the plan!

I ran out of daylight today, so the rest of this will have to wait a while.

I started my first Jeep project of 2019... Woo-Hoo! :thumbsup:
 
Last edited:

barrys

Scrambler Junkie
LIFETIME
CJ-8.com Member
City
East Norriton
State
PA
#2
What about cutting a slot from the back forward, hammering the 2 halves flat and welding it back up?
 

jammer1

Scrambler Junkie
LIFETIME
CJ-8.com Member
City
Maple Hts.
State
Oh
#4
That would beat heating it up with a torch and hammering it into shape. Probably safer with the fuel tank close by.
 

CJ7Pilot

18436572
LIFETIME
CJ-8.com Member
City
Yuba City
State
CA
#6
That would beat heating it up with a torch and hammering it into shape. Probably safer with the fuel tank close by.
I think I would remove the fuel tank before proceeding any further :thumbsup:
Yep, I was pretty conscious of that today when I used my plasma cutter (and yes, I took precautions)!

I think when it's time to weld on the new cross member, it will be a good idea to drop the tank and move it out of the way!
 

CJ7Pilot

18436572
LIFETIME
CJ-8.com Member
City
Yuba City
State
CA
#7
Finally, a beautiful day to finish this up! :headbang:

For starters, I moved the fuel tank completely out of the way!

tank - 1.jpg

I ended up pie-cutting the warped bolt holes, and pounding them flat. It worked like a charm!

I got the crossmember in place, centered, and welded up.

Now, I'm not a professional welder... I'm a hobbyist at best... but I've got a new-found respect for those who do it for a living!

Most of my projects include brand new steel, up on my welding table, clamped and jigged, and it works out pretty well!

Well, today I had to weld new steel to old steel (admittedly, I could have prepped it better), laying on the ground. Well, it turns out that my overhead/vertical welding skills suck, and I'm pretty worn out!

So... you don't get to see photos of my welds (fortunately, they're all hidden behind the crossmember), but here's the finished product:

rear - 1.jpg

And, the receiver hitch is pretty square:

rear - 2.jpg

Unfortunately, I didn't think to install the rear body bushings before I welded it up, so tomorrow I'll have to loosen all the other body bushings to create enough space to install them. :shrug:
 

jammer1

Scrambler Junkie
LIFETIME
CJ-8.com Member
City
Maple Hts.
State
Oh
#9
Looks good. Now it needs a good bumper and tire carrier. In a way, it would be a shame to hide such a nice rear cross member.
 
City
Vero Beach
State
FL
#13
I've got the new cross member and new body mount isolators sitting in my garage waiting for free time. Thanks for putting this up as I probably would have welded mine on without putting the rubber isolators on too but for your mentioning it.

I also bought the Rock Hard rear cross member brace to help hold it true while I welded it. Has anyone here used those?

Chamba
 

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