Rear Quarter Panel Clearance Cutting - New Technique

[Nay]

Well, it might not be a new technique, but I'll stake a claim (for SROR, it's just my truck)

As a part of my rear bumper build at SROR, I cut the rear quarter panel bumperette mounts for clearance. My concern from the start had been that by cutting then off entirely and going with a tube bumper that I'd end up with a bunch of empty space, so I decided to level them with the lines of the body. This meant cutting them about halfway through.

As you can see by the pics, cutting much more than this gets you into relocating the drain tubes on each side - at the halfway point you don't have to mess with that stuff. But you still have the seal them back up somehow.

My plan had been to bolt in some angle iron on the inside of the cut to the sheet metal (one on each side of the opening) and then have Jim (SROR) weld a plate over the angle iron and I'd deal with sealing what was left open. After some consideration during the project, we decided to maybe just bolt on a small plate to the sheet metal to create a thicker weld surface and then weld a 3" wide piece across to the bottom of the plate when Jim had a brilliant idea: bend 1/8" thick 3/4" width stick to the shape of the opening, tack the 3 sides together and pull them out of the opening, weld on a 1/8" thick plate and cut/grind it to the shape of the "mold" created by bending/tacking the 3/4", and then insert the entire thing back in to be bolted together with the self tapping screws I had bought.

It worked brilliantly. The new "floors" fit back in so snugly that they stayed in on their own. I tapped 6 screws through the sheet metal and the side of the new floor on the outside and 2-3 on the inside. The net result is a perfectly level 1/8" thick floor to the cut panels that is now structurally part of the quarter panels. It's not indestructible, but pretty damn sturdy and protected by the bumper.

There is a lot of waffled angle in the inside wall when you cut it off that needs to be filled after the new floor is bolted in. I used a little bit of expanding foam in a couple of these areas and then caulk to create a flat edge. Then I have sealed all of the edges, most of which are very tight to begin with and have very little gap, with "Fast Steel", which is a putty epoxy metal filler that cures in minutes. It is now fully sealed with the new rigid floor and metal filler around the entire perimeter.

The net result is an extremely clean look that is much stronger than attempting to seal with sheet metal. I'll take more pics of the finished job along with the bumper so you can see how the final product follows the lines of the rear of the body.

Kudos yet again to SROR for the extra mile and quality fab work. I was really concerned about how to gain the clearance for a good tube design without butchering the panels and/or ending up with a mess that was difficult to reseal. We nailed both of them. to SROR! I hope to see Jim be able to market and sell these for DIY cut and seal jobs because this is such a barrier to a custom rear bumper.

The first pic shows the side view, the second shows the passenger side view from underneath, and the third shows what you have to deal with by cutting much more (drain tube, etc on the driver's side - the passenger side is cleaner but also has a drain tube).

 

[badmuthatrucka]

Nice work Nay and Jim! I am just wondering why there are so many extra bends in your rear quarter where you did the cutting?

 

[Nay]

Nice work Nay and Jim! I am just wondering why there are so many extra bends in your rear quarter where you did the cutting?

That's the way the inner wall is formed. I have no idea why

It gets worse the more you cut, there's an inner piece as well that you have to deal with that starts right about where I cut.

 

[Dusty]

nice Nay. I will be cutting up/expanding the front wheelwells and my rear fenders to stuff the 42" Iroks in my build. I too have been thinking of ways to avoid welding such as you have done. keep the pics coming

 

[Nay]

The sheet metal in the rear is way too thin to effectively weld. Now, the "floor" we built is welded to create that 3/4" tall wall that we bolted the sheet metal to. I'm not sure how you'd clearance for 42" IROKs eek:) and not do some welding.

Think 3/4" width 1/8" thickness as a good insert piece as you scope it out. That stuff bends around the various body lines easily once you open it up.

I'll post final pics later today.

 

[Atoyot1031]

Cool Nay! Chop, chop, cut, cut! I like it. Your 80 must be getting light these days.

 

[Tools R Us]

Looks great!

The bumper is getting more bracing/triangulation right? I made something like that and it "worked" for my needs, kept the tupperware from falling off, but wouldn't take much of a rock hit! It was a bend, straighten with the forklift, bend, repeat,,,

 

[Nay]

Yes, we are going to add some additional bracing when we do the d-ring mounts. That's why I haven't posted any pics of the bumper itself yet

What tube diameter/gauge did you use? Mine is 2" 11 gauge (.120 wall).

 

[Nay]

Cool Nay! Chop, chop, cut, cut! I like it. Your 80 must be getting light these days.

In total I will have lost about 40-50 lbs of weight over the stock bumper/crossmember, spare tire winch, and hitch (Slee receiver). I am not mounting a hitch integrated in the bumper - it will only have D-ring points and I'll actually bolt up a regular hitch for the 1-2 times a year that I tow.

In total, my two bumper projects have reduced the weight of my 80. I'll be able to add a lighter winch like a 9.0Rc and only be at stock weight.

 

[CreeperSleeper]

I pulled my 80 in the garage last night to start cutting the 1/4s... Any more pics of how you did this would be appreciated!

 

[Tools R Us]

Yes, we are going to add some additional bracing when we do the d-ring mounts. That's why I haven't posted any pics of the bumper itself yet

What tube diameter/gauge did you use? Mine is 2" 11 gauge (.120 wall).

Mine was 1.5" x .120 wall, it bent way too easy.

 

[Nay]

Mine was 1.5" x .120 wall, it bent way too easy.

I was looking at the picture and wondering how you got that much bend. It's interesting watching the 2" on the tube bender. You have to go past the desired angle as the stuff springs back a lot more than you'd expect. Same thing happens on impact.

Mine has a gusset from frame rail to tube on the inside of the frame rails and we're doing the same on the outside of the frame rails (where yours bent) when we do the d-ring mounts this week.

Part of the other reason I wanted a solid floor was so that if the brace back to the frame does bend up it should stop way before introducing a permanent bend unless I hammer it so hard I'd be effectively destroying a typical stamped rear bumper on that side. Not saying that can't happen, but to date with no protection on those corners I had only put a small bend in the seam weld on one side.

You could build a small bracket on the frame rail to create an upper mount point for the wing brace tube to be triangulated. I'm going to look at that, but I'm not really sure there's much valued added. As with all things, time will tell.

In any case, go 2" next time

 

[Nay]

I pulled my 80 in the garage last night to start cutting the 1/4s... Any more pics of how you did this would be appreciated!

Here are pics of the basic sealing job using the Fast Steel. This stuff is great to work with - you knead it in your hands to mix the two elements and then you have 3-5 minutes of working life where it is putty. Then in an hour its fully cured and hard as, well, steel

From the first pic you can see that I kept the cut essentially level with the body line from the rear so it wouldn't be a visual gap. I just marked a start point and then used a level with a sharpie to mark the cut line. Those panels slope downward as they approach the tire, so the cut is not entirely level to the body line that remains.

I used a grinder with cutting disc, which is a lot of work because the disc wasn't big enough to do a single cut. I had to remove the outer side first, clearance as needed stuff inside, and then do the inside cut. I was conservative on the first cut so I could grind it level later. I still cut a bit high in spots, but the floor solution we built leveled it all back out, and you can see the Fast Steel covering the seam where the sheet metal hits the new floor.

It would be a ton easier with a sawzall for sure

Fast Steel is sandable, grindable, drillable, paintable, so even though the putty strips on the larger gap areas look a bit , it's the underside and the stuff is completely rigid and bonded. I have some leftover and am going to give those larger gaps a final surface coat, but I doubt I'll bother with any kind of sanding. Just going to prime and paint. I did use some caulk in the larger gaps, but upon retrospect, it would take maybe 6 sticks of the fast steel to do it all and they cost $2.50 each. Kind of a no brainer to have a fill of that strength.

Hope that helps.

 

[Dusty]

Nay I am curious to see how that playdough steel stuff holds up. welding the sheetmetal in the rear fenders is doable and is not to thin. Just takes a lot of patience and thought and carefull fabrication.

 

[Nay]

Nay I am curious to see how that playdough steel stuff holds up. welding the sheetmetal in the rear fenders is doable and is not to thin. Just takes a lot of patience and thought and carefull fabrication.

It's just filler, remember, not structural in any way. In all honestly, I could have easily just caulked it and called it a day but some of the seam was so tight I really wanted a complete cover that was more than a bead of caulk. If for some reason there is flex that cracks the filler, it'll be clear caulk from that point out.

You can weld the sheetmetal - I don't want to suggest you can't. This approach is a bit more modular in the sense that if you know a fabricator or can do a simple tack weld you could make this thing yourself without the fear that a screw up takes you past a certain point of no return.

That was my fear as a non-practicing fabricator, but then on Thursday I'd been sitting at a desk all day and was losing my mind so I went out and plugged in the grinder and said fawk it. As my wife came home in the minivan with the kids the driveway was a shower of sparks in the gathering dusk.

She said "cool" and went inside. It wasn't until I told her that my flashlight had fallen out of the bottom the now unsealed Cruiser that she shook her head at me and laughed. I'm honestly thrilled right now that it is actually sealed again before the next storm, forget about clearance. I gotta get that new bumper primed and painted

 

[Tools R Us]

I was looking at the picture and wondering how you got that much bend. ...

It was very easy, drop off of a big ledge and bang, bent! The tube would get hung in the rocks and bend back. Mine was a quickie, welded to the receiver hitch, yours is mounted higher, so may not have as much problem?

In any case, go 2" next time

That setup was only temporary. The Luke bumper that replaced it is way stout, have banged it way hard and hardly a mark.

 

[NW-sickboy]

any more pictures of the bumper? how much of the frame did you remove? what kind of a cross memeber was put in? are you planning on adding any type of wing or kick outs of any kind.. i like how its tight but i would think you would want something to keep you off the rocks.. no?

 

[Nay]

any more pictures of the bumper? how much of the frame did you remove? what kind of a cross memeber was put in? are you planning on adding any type of wing or kick outs of any kind.. i like how its tight but i would think you would want something to keep you off the rocks.. no?

Here are some pics of the initial design (sorry the first pic isn't level due the the glacier that I call a driveway )

In terms of frame length, we simply cut the stock stuff off at the points it mounts to the bumper, leaving the frame alone. The bumper tube is set into the top of the frame (welded), and then the frame is cut at an angle and sealed.

The reason I did not want to pull it in any tighter you can see in the third picture - if you run a level against the outermost point of the hatch (the middle of the upper hatch) down to the bumper, the result is the bumper is just outward of that point by about 3/4". If it was any tighter, then backing into a pole would mean the hatch would take impact before the bumper.

With the "slider" angled trim, the underside of the frame has a rear point that is probably 4" shorter than stock.

One additional point that becomes pretty glaring is the crappy placement of the exhaust. I now have room to run it over the frame rail and into the open corner pointing downward at the level of the bumper. When that is done, it will disappear from view (and impact placement).

 

[Nay]

There is not a crossmember in the same way the stock setup does not have a crossmember but is triangulated. On initial design, we added gussets from the frame inward (first pic) to create that triangulation. When we do the d-ring mounts, which will be right at the frame mount, we are also going to add gussets from the frame out to the corner.

I am thinking a simple sheet of 3" wide 3/16" across the entire length (frame to frame) would provide final reinforcement, with the existing gussets providing triangulation both to that piece as well as the tube. That would be nice visually when looking down on the bumper (tube) as it will fill the gap between body and tube. Although that might add 7 or 8 lbs .

As far as side protection, I am not planning wings or hoops right now. The bend is tight around the corner to follow the body lines, and we did not do a 90 degree angle. The body line goes out as you approach the wheel well, and the bumper line follows this. I could still get some denting from a low angle lean, but the bumper will stop any damage more than a "pop-in" unless I am leaned it up high on a tree or rock, which no bumper will stop.

Again, if you use a level against the widest point of the rear quarter panel, the wing almost protects it along the entire length, but that part of the body is not a straight line and it's a balance between tucking and protection. I had nothing out there for over a year, not even plastic, so in the generally more wide open Western wheeling this was the balance I wanted.

In the picture it may look like the bumper extends out past the tire, but that's just the angle I took it at. It is fully contained behind the tire tread.

 

[Nay]

This is what the bumper looks like from a distance view. You can see the clearance achieved on a 3.5" lift. The only visual change from this angle will be the addition of d-ring mounts and a nice coat of black paint

So all that is left is what to do with the spare, since I do not want a carrier as I use the hatch all the time. I have ordered a 35x10.5x16 SSR, because my 35x12.5x16 trxus MT will almost fit standing up behind the 3rd row. It just presses on the glass a bit. The 10.5 SSR should fit fine. So I can put it back there when I need the entire roof rack.

However...I am going to see if it is possible to get the 10.5 tucked up enough under the stock position to carry it there for daily driving and light duty wheeling, and I'll put it up top when I get serious. A bit of a pain to move it around, but it's not the daily pain or weight/visibility loss of having a tire that big out on a carrier.

Worst case I gained 2" of clearance on the roof and can stow it behind the 3rd row when needed.