Trimming rear tub—leave corner armor on or take it off?

pc1p

pc1p

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Quick question for the brain trust:

When trimming the tub with armor, is it best to trim the tub first, then trim the armor - OR - trim both at once? I've trimmed many a fender before but I have never trimmed a fender with armor, so I figured it was worth an ask...

I seem to be clear in the front (for now) but I'm hitting hard in the rear (I've got another 1.5-2" of uptravel to go here):
IMG_1347.JPG


I found some old AEV Hi-Line instructions and they have a good guide-sheet. I may trim the front as suggested while I have the tools out and the wheels off:
AEV.JPG
 
We always trim them together since even someone as good as I am will struggle to get both cuts identical. We cut them with a good jigsaw, angle grinder with aluminum cut off disc. The sheet metal will wear the aluminum cutting disc but it is better than the one for steel loading up with aluminum. After the cut, we smooth with a flap disc so it is nice, deburr the outer sharp corner and the steel. That is the only way to get a perfect match easily. You can cut the armor, reinstall it, scribe the cut onto the body, pull the armor, cut the body and then put the armor back on if you insist on doing it the hardest way possible.

If you use a jigsaw, put a few rows of masking tape on the good side of the cut to keep the aluminum bits that get under the jigsaw base from scratching the armor.

If you live in a rust area, pull the armor after the cut and treat the steel.
 
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pc1p said:
Quick question for the brain trust:

When trimming the tub with armor, is it best to trim the tub first, then trim the armor - OR - trim both at once? I've trimmed many a fender before but I have never trimmed a fender with armor, so I figured it was worth an ask...

I seem to be clear in the front (for now) but I'm hitting hard in the rear (I've got another 1.5-2" of uptravel to go here):
View attachment 217795

I found some old AEV Hi-Line instructions and they have a good guide-sheet. I may trim the front as suggested while I have the tools out and the wheels off:
View attachment 217796
Click to expand...
We pull the springs and cycle the axle with the tires on, shocks on no bump stops. We also do not pay much attention to full stuff since that is always lower than full articulation. If you have interference at full stuff, it will be much worse under articulation.

Jack up one side until the tire hits, hold it there. Lay a piece of rubber hose on top of the tire about the size you want for the gap, push that over to the armor, trace on the outside of the hose letting the mark daylight at the upper and lower ends. Lower tire, cut, repeat until you get the clearance needed. Balance your gaps against the amount of up travel you have left.

You don't want to have a piece of 1" diameter hose on there if you only have a half inch left to go up. That makes the opening in front and behind the tire larger than it needs to be.
 
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mrblaine said:
We pull the springs and cycle the axle with the tires on, shocks on no bump stops. We also do not pay much attention to full stuff since that is always lower than full articulation. If you have interference at full stuff, it will be much worse under articulation.

Jack up one side until the tire hits, hold it there. Lay a piece of rubber hose on top of the tire about the size you want for the gap, push that over to the armor, trace on the outside of the hose letting the mark daylight at the upper and lower ends. Lower tire, cut, repeat until you get the clearance needed. Balance your gaps against the amount of up travel you have left.

You don't want to have a piece of 1" diameter hose on there if you only have a half inch left to go up. That makes the opening in front and behind the tire larger than it needs to be.
Click to expand...
That sounds like a good approach (the hose as a guide) that I haven't heard of before. I have done something similar, flexing one side at a time, marking interference and trimming up a little bit at a time until I get the clearance I wanted. Instead of hose, I used a thin piece of sheetmetal to get a nice arch, alongside some well placed c-clamps to get a nice shape. I even used a piece of fiberboard one time to make a "template" of the cleanest larger size, then transferred that shape/size to the other side to make sure they all match (I just marked with a marker and then used a flapdisc to even it out).

Thanks for the tips!
 
mrblaine said:
If you live in a rust area, pull the armor after the cut and treat the steel.
Click to expand...
I live in the desert - but will still be removing the armor in a short time to repaint the rig, as well as paint the armor, sliders, etc. :)

Hopefully the single-stage Summit Racing Catalyzed Urethane is as good as everyone is saying...
 
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mrblaine said:
We always trim them together since even someone as good as I am will struggle to get both cuts identical.
Click to expand...
If ya'll are interested, I'll pull out the two pieces I cut separately from each other when I did the rear corners on the TJ-6 to give you an idea of my actual skill cutting freehand with a jigsaw on two corners that I traced around stock openings onto a pair of blanks.
 
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mrblaine said:
If ya'll are interested, I'll pull out the two pieces I cut separately from each other when I did the rear corners on the TJ-6 to give you an idea of my actual skill cutting freehand with a jigsaw on two corners that I traced around stock openings onto a pair of blanks.
Click to expand...
any particular jig saw blade work best?
 
@pc1p, how did you end up trimming that corner? I am about to do the same after moving my axle back a few inches. Don't want to buy new corners, seeing as mine are powdercoated. I was thinking of using a jigsaw and then finishing with a flap disc.
 
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Milwaukee 6” “Thin Kerf” 18TPI
3M Cubitron 2 (80 grit) flap disc

Cut like butter even with the slight radius. Picture is deceiving...looks like there is a slight lump towards the rear upper portion of the wheel well. It is just the original body lip that you can see on the slight angle the picture was taken. The opening itself is smooth and flows nicely
 
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Rock Toy said:
@pc1p, how did you end up trimming that corner? I am about to do the same after moving my axle back a few inches. Don't want to buy new corners, seeing as mine are powdercoated. I was thinking of using a jigsaw and then finishing with a flap disc.
Click to expand...
FWIW - this is exactly as I'm planning on doing (I just need it to stop raining on my free days :))
 
Trim them both together. Just did this to clear my 40s. Exactly how Blaine described, cut off wheel, then a flap disc to smooth out. Very easy to do, just take your time. I just painted over them but am thinking of sealing them somehow. The flare bolts at the corners hold sandwich all 3 together.

I moved my axle back a bit after too for more clearance

20210128_210146.jpg


20210125_110036.jpg
 
LieutenantJohnson said:
Trim them both together. Just did this to clear my 40s. Exactly how Blaine described, cut off wheel, then a flap disc to smooth out. Very easy to do, just take your time. I just painted over them but am thinking of sealing them somehow. The flare bolts at the corners hold sandwich all 3 together
Click to expand...
What did you do with your Evan canister on the passenger side? Mine is now flush with the wheel well opening now that I have trimmed it back. I would like to move it either further to the rear or relocate all together.
 
Sunny Side Up said:
What did you do with your Evan canister on the passenger side? Mine is now flush with the wheel well opening now that I have trimmed it back. I would like to move it either further to the rear or relocate all together.
Click to expand...
It is still there but not doing much. I swapped an LS in last year and deleted all emissions. Just have 2 O2s below the headers for tune.
A buddy of mine in Nevada made some Aluminum block off plates for me to cover the "voids" left from removing the inners. Just need to paint tub and install them.

Note. Picture was pre fender trimming and clean up :)

20210124_141506.jpg


20210124_141302.jpg


20210124_141619.jpg
 
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