RuffStuff Frame Stiffeners (XJ)

Old 05-05-2013, 04:03 PM
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Join Date: Jun 2011
Location: NoVA
Posts: 64
Year: 1999
Model: Cherokee
Default RuffStuff Frame Stiffeners (XJ)

I decided to do a detailed How-To because of the lack of information out there about how an amateur might go about tackling this install. You will definitely need to be competent at welding, or know someone that can weld (in my case). I suggest reading this entire How-To at least twice to ensure you have everything you need prior to getting started, as well as to understand what needs to occur.

The results of this mod are without a doubt night and day. I drove 1.5hrs before starting and noted every creak/pop/tweak the dash/body made (quite a few!). On my way back home, I realized they had ALL disappeared. The ride feels smoother, but most importantly, the body feels SOLID.

Please feel free to PM me any questions you may have!

For a full photo gallery, please click the link below:

Install Time: 8-12 hrs
Dividing up the work among two people took 8 hrs for my XJ (not including meal breaks). There was one dent in the passenger frame rail, but nothing too bad. To my knowledge it's never had a lift installed, but it has certainly seen some dirt.

Here are the tools we used (other than the standard hand tools):

(no photos for these)
Angle Grinder
Bottle Jack
Huge C-clamp (a.k.a. Big Bertha)
Big Hammer
Floor Jack
Level (bubble or digital)
Jack Stands (qty.5)
4x4 Blocks (5-10)

Die Grinder (to remove undercoating)

Air Sander w/ 80-grit paper (to remove paint)

Mig Welder
(settings shown are what we used; wire speed varied from 4-5

.025" Welding Wire
(we used approximately 1.5 spools)

Ar/CO2 Gas at 35 SCFH
(we used approximately 1000 psi of gas from a 95 cu.ft. tank)

1. First get the XJ on jackstands. The height is up to you, just remember you'll have to do a lot of welding, so keep it at a height that will be comfortable.

2. Next, ensure the frame is not twisted due to an uneven floor. This is to ensure the frame is in an unloaded state prior to welding. I used the cross bars (with the large hole near the center of the photo) behind the front/rear bumpers (front bumper shown).

3. It does not need to sit exactly at 0 deg. As long as the front and rear match, you are good to go. Mine read 1.2 deg front and rear.

4. Next, you will need to remove the transmission crossmember. It consists of qty.4 13mm bolts, qty.2 13mm nuts, and qty.2 15mm nuts. Use a jackstand to support the transmission/transfer case PRIOR to unbolting the crossmember (best photo I have of this).

5. Remove the E-brake bracket (rear end of driver side frame rail). It consists of qty.2 13mm bolts.

6. Mock up each stiffener to the frame rails to see where any modifications might have to occur. I am still on a stock suspension setup; therefore, I had to cut off the leading ~8" of each stiffener (as RuffStuff states on their website).

7. I also had to bend the trailing end of each stiffener to match the contour of the rear frame rails.

8. The last modification was to the inner-surface near the rear of each stiffener. There is a piece of metal welded to the frame rails that prevents the stiffeners from sitting flush.

9. Using an angle grinder, remove material from the stiffener in order to clear this piece of metal.
(note Sharpie marks in below image)

10. Place each stiffener back up against the frame rails and mark EVERY rosette hole, slot, and oval shaped hole (example shown below). Also, if desired, mark every 4-6 inches for a 1 inch stitch weld along the inner/outer edges of the stiffeners (it works out to be a mark between each rosette hole). These will be where you need to surface prep for the welds.

11. Using the die grinder, remove the undercoating (if any) at each marked location. Be sure to remove approximately 1.2" around each marked location to ensure enough metal is exposed (see image above for an in-progress example).

12. Next, use the air sander with rough sandpaper (I used 80-grit) to [easily] remove any paint from the frame rails.

13. Once all surfaces are prepped, use BrakeClean to remove any dirt/residue from the bare metal. Side Note: Ensure the angle grinder is not in use! Otherwise, your fire extinguisher will require a recharge (long story!).

14. Using a floor jack and a 4x4 block, secure a frame stiffener against the frame rail near the front. Using a stack of 4x4 blocks, a bottle jack, and a big C-clamp, apply pressure to the rear of the stiffener to ensure it is flush with the frame rail.

15. Tack-weld a few places to set the stiffener in place. Then, move the stack of 4x4 blocks, bottle jack, and big C-clamp down towards the front; tack weld as you go. Important places to apply pressure with the bottle jack are at the relief cuts in the stiffener (see above image). This will ensure the stiffener forms to the contour of the frame rail.

16. Once the entire stiffener is tack-welded in place, finish up by filling in all of the rosette holes and applying 1-2 inch stitch welds along the edges.

17. Repeat Steps 14-16 for the other stiffener.

18. To prevent corrosion/rust, apply paint or undercoating to all bare metal. I used RustOleum Professional Grade Undercoating Spray (one can per side). Mask the mounting holes for the transmission crossmember, as well as the transfer case, transmission, exhaust, etc (I used plastic sheet draped over areas I did not want overspray). Also, sand the bare metal using rough sandpaper (I used 100-grit).

19. Re-install the transmission crossmember. You will need longer 15mm bolts (qty.2) due to the increase in distance caused by the stiffener. We had some lying around, but you will need at least 3/16" longer than stock.

20. Because of the added distance, the studs in the frame rails that are used to secure the crossmember are too short by approximately 2-3 threads. We could not easily remove them (seemed pressed in), so we used Red (permanent) Loctite on the original 15mm nuts (qty.2).

21. Re-install the E-brake bracket using the qty.2 13mm bolts (these will need to be longer, as well).

22. Remove the jackstand supporting the crossmember.

23. Lower the XJ back onto the ground.

24. Enjoy the difference!

Last edited by speedofsound; 05-06-2013 at 11:01 AM.
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