After a hiatus, I need an opinion...

[Spinnakerblue89]

I never left, but I had so much stuff going on that I had to effectively put the Pioneer on the back burner. Now I have my eyes set on it again. 

 

So to recap- I have to weld on new floor panels, inner and outer rockers, cab corners, and the cab supports. I already have the two floors cut out, but what being that the MJ is a unibody, I wonder what order I should go in putting these parts on? 

 

Basically, I wish to avoid stressing the frame or letting it stand without sufficient support, whatnot...

 

Thanks!

[coheed]

I only did the floor pans and frame caps on my truck, but I would think if you're spot/plug welding everything I wouldn't worry about residual stress in the frame. Unless you're using an industrial spot welder you're gonna be going a lot slower than the factory when welding. Meaning heat soak is gonna be a lot less of a factor.

 

I would worry more about warping the rocker panels and cab corners with heat since they're sheet metal. As long as you work slow (but weld quickly) and let things cool properly I wouldn't worry about it too much.

[Spinnakerblue89]

So should I do the rockers first or floor pans first? I get the heat concerns but I'm always trying to figure out what sequence would make the best sense too...

[89 MJ]

I would do the floors first. It’ll be a good refresher that very few people will ever see again. 

[Pete M]

seeing as some MJ are driving around with essentially no rockers or floors, I think you'll be ok either way.    but yeah, I'd probably start with the floors and move outward from there.

 

don't forget to seal up EVERY leak.  there are many.  

[Spinnakerblue89]

That's about what I was thinking. Best to cut my teeth on something invisible. 

 

Appreciate the feedback, folks! 

[A-man930]

I tacked-in a makeshift angle iron brace when I had the floors and firewall all cut-up.  Not sure if it made a difference 

[Spinnakerblue89]

On 6/9/2026 at 7:40 AM, A-man930 said:

I tacked-in a makeshift angle iron brace when I had the floors and firewall all cut-up.  Not sure if it made a difference 

Added structure maybe? 

[The86manche]

On 6/7/2026 at 9:56 AM, Pete M said:

seeing as some MJ are driving around with essentially no rockers or floors, I think you'll be ok either way.    but yeah, I'd probably start with the floors and move outward from there.

 

don't forget to seal up EVERY leak.  there are many.  

I started at the rocker. My thoughts were to have the inner rocker replaced firsts there would be no working around the floor. And I can put the floor in and work it to the rocker instead. I'm leaving the outer off until the floor is burned in so I can clean up the burn marks from the welder on the inner rocker. Then put the outer panel on

[AZJeff]

On most unibody vehicles, the rocker panels comprise a significant part of the longitudinal stiffness of the chassis structure. 
That is NOT the case on the MJ/XJ vehicles, as they have a boxed rail under the floor pan that constitutes a type of integral frame rail down the length of the chassis.

because of this, I recommend fixing the floor pans to increase overall longitudinal stiffness before attacking the rocker panels (which are more cosmetic on the XJ/MJ)