Spinnakerblue89 Posted June 5 Posted June 5 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 Posted June 5 Posted June 5 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 Posted June 7 Author Posted June 7 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 Posted June 7 Posted June 7 I would do the floors first. It’ll be a good refresher that very few people will ever see again.
Pete M Posted June 7 Posted June 7 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 Posted June 8 Author Posted June 8 That's about what I was thinking. Best to cut my teeth on something invisible. Appreciate the feedback, folks!
A-man930 Posted June 9 Posted June 9 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 Posted June 10 Author Posted June 10 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 Posted June 11 Posted June 11 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 Posted June 11 Posted June 11 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)
Spinnakerblue89 Posted August 14 Author Posted August 14 Thank you for your input. I had to take an unplanned hiatus again due to a random heart attack that nobody has answers for, no blockage or anything, possibly nerves. Had an operation for SVT and now I'm all set to go. Looks to be a rainy weekend, so I'll spend the weekend practicing on the welder. And since it seems like the floor pan is being suggested as the starting point, I'm actually quite glad because it's the one area I'll only know about and for a first job, it's a little more forgiving if my welds are not so pretty. No worries about me, I'm actually in fine fettle!
Spinnakerblue89 Posted Sunday at 11:08 PM Author Posted Sunday at 11:08 PM Hey, what's the word on spraying rust preventative inside the inner frame rails while the floors are out? I've heard of cavity wax being used...
Pete M Posted Monday at 02:05 AM Posted Monday at 02:05 AM if you have real access to the inside of the frame, you can apply the por-15 type products.
A-man930 Posted Monday at 03:21 PM Posted Monday at 03:21 PM 16 hours ago, Spinnakerblue89 said: Hey, what's the word on spraying rust preventative inside the inner frame rails while the floors are out? I've heard of cavity wax being used... If there's access, go with a 2k epoxy wherever possible. Cavity wax through a diffuser tip for areas you can't get at AND periodically/seasonally after that.
Spinnakerblue89 Posted Tuesday at 05:14 AM Author Posted Tuesday at 05:14 AM Okay, I understand the value of POR15, but I'm admittedly less educated on 2k epoxy. What is the benefit of going that route? Also, I have searched this question online, but seldom is there a consensus because there really aren't any good ten year studies on these sorts of things- it all depends on location and climate, in addition road treatments. If it helps, I live in Indiana. We salt our roads...
jodawill Posted Tuesday at 01:03 PM Posted Tuesday at 01:03 PM 7 hours ago, Spinnakerblue89 said: Okay, I understand the value of POR15, but I'm admittedly less educated on 2k epoxy. What is the benefit of going that route? Also, I have searched this question online, but seldom is there a consensus because there really aren't any good ten year studies on these sorts of things- it all depends on location and climate, in addition road treatments. If it helps, I live in Indiana. We salt our roads... I watched some videos about POR-15 (after I had already ordered mine) and it had the worst performance of all the coatings tested. I think it will be fine on my floor because it's not going to see any wear, but I wish I had seen this before I bought it. What part of Indiana are you in? I'm in Noblesville.
Spinnakerblue89 Posted Tuesday at 01:46 PM Author Posted Tuesday at 01:46 PM 38 minutes ago, jodawill said: I watched some videos about POR-15 (after I had already ordered mine) and it had the worst performance of all the coatings tested. I think it will be fine on my floor because it's not going to see any wear, but I wish I had seen this before I bought it. What part of Indiana are you in? I'm in Noblesville. I didn't want to start anything, but I already have a Mastercoat kit for the underbody. Interior-wise, I may do the same because they have an additive to make the coating into a mild sound deadener and insulator, and I will also be adding additional deadener pads and insulator to the mix. I'm just outside of Bluffton, which is south of Fort Wayne. I've been to Noblesville before, should come as no surprise that I went to see a few concerts at the old Verizon music center there.
jodawill Posted Tuesday at 05:48 PM Posted Tuesday at 05:48 PM 4 hours ago, Spinnakerblue89 said: I didn't want to start anything, but I already have a Mastercoat kit for the underbody. Interior-wise, I may do the same because they have an additive to make the coating into a mild sound deadener and insulator, and I will also be adding additional deadener pads and insulator to the mix. I'm just outside of Bluffton, which is south of Fort Wayne. I've been to Noblesville before, should come as no surprise that I went to see a few concerts at the old Verizon music center there. We go that way occasionally to visit Sweetwater or to visit people in Ohio.
Spinnakerblue89 Posted Tuesday at 07:20 PM Author Posted Tuesday at 07:20 PM Oh yeah, Sweetwater is definitely expanding now. That's easy to see.
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