I got an XJ that has a crack in the floor kind of between the inner rear floor mount seat belt mounts, on the hump in pan.

Is this a known issue on XJ that is wheeled?

Rust free, never wrecked. Was greasing the drive shaft when I noticed this, was not present a year ago I am fairly sure of that.

Is there a recommened repair... doubler, or ?

Thanks in advance for your insight.

 

You will need to find out if it is do to it flexing or why it did that . you mite need to add in stuff to help the fame to make it stronger . I never herd of them cracking there with out rust .

 

photo.. Top of tunnel under rear seat. Two cracks circled in black. Rust free top and bottom
wheeler, 33x12.5 tires 5.5 lift.
center frame stiffeners installed about a year ago. didnt notice cracks till now. maybe they were there before stiffeners installed, maybe not.

 

I would jack it up from one corner and see if the frame is flexing . for the cracks they look like all you need to do is weld them up .

 

When I installed my stiffeners, I completely removed all the undercoating, and I had cracks in that exact same spot. Since I was under there anyways welding, I went ahead and ran a bead along the cracks. Drill small holes at the end of the cracks to keep it from spreading. Use a series of small tacks, spread out, and repeat until filled. I ground down the tack bead to make sure there wasn't any inclusions, then tack welded another bead just for additional strength. Prime and undercoating finish the job.

I often wondered why it cracked there, then I remembered. Had a ujoint on the driveline give way, and it beat the **** out of everything down there. Anyways, I repaired it and haven't had a problem since. Hope this helps