I would like to hear from others who have drilled drain holes in their TJ frames. I have inspected mine inside and out for rust . I don't see anything, not even surface yet and I'm in New Mexico where it is dry, not much snow and I don't think they use salt here. Still, some of the frame pictures I've seen on this site are unreal with rust damage. I have heard it both ways, it's ok to drill drain holes in the bottom, and some have said you should not because it weakens the frame. There must be some reason that Jeep did not put drains in the bottom. I would like to be able to hose out the frame inside once in a while but I don't cause I can't drain it out. What have others of you done about what seems like a very odd design weakness.
Frame Drain Holes
- Thread starter Peter Panagakos
- Start date
Imapepper
TJ Enthusiast
I have the auto trans. Is this the hole for the front bolt on my trans skid plate? From this picture the hole looks like it's not far from the front suspension arm bracket. I don't think I have any hole that far forward. May be it's just the angle of the picture.
MountaineerTom
LJ Enthusiast, Retired USAF Weapons Loader
Supporting Member
Ride of the Month Winner
I drilled 5/16 (or maybe 3/8, I can’t remember) holes about 1-1/2 inches away from each lower control arm bracket.
If you have a 4 speed, that hole is filled with the bolt / nutsert for the stock transmission skid. If you have a 3 speed, that hole doesn’t exist at all.
Living in New Mexico, I would forget the drain holes. It wouldn’t hurt, but I also think it is a waste of time. Your frame isn’t going to rot out down there. Just be sure to keep it from filling with dirt by washing it out every once in a while.
Technically, speaking in structural steel terms, round holes with no "notches" in them do not weaken the member as long as they are not too large of a diameter in proportion to the member.
I do live in the salt assault area of the world and I have been considering adding some holes to that I can properly wash and drain the frame. As well if I do this I will be capping/covering the large holes on the side of the frame by the rear wheels so that the major entry point is not there in the first place.
I'll likely do about 1" or 1 1/8" diameter.
I do live in the salt assault area of the world and I have been considering adding some holes to that I can properly wash and drain the frame. As well if I do this I will be capping/covering the large holes on the side of the frame by the rear wheels so that the major entry point is not there in the first place.
I'll likely do about 1" or 1 1/8" diameter.
I would want them as they allow you to thoroughly wash/flush the frame. Anyone who says a 5/16" hole with make the frame weak is full of shit.
That's true. I have had many Jeeps here in Newer Mexico, and rust was never a problem. The TJ frame just bugs me because the older Jeep CJs had issues with the body hat channels and floor boards, but not the frame. I see pictures on here very often that show pretty clean bodies with destroyed frames. Just seems weird. Any one know why the TJ frames have holes in the sides high enough to catch all kinds of wet and dirt, but not low enough to drain it. I guess if my TJ stays in Newer Mexico it will probably never rust so I'll just be gratefull I'm not in the rust belt and shut up.
MountaineerTom
LJ Enthusiast, Retired USAF Weapons Loader
Supporting Member
Ride of the Month Winner
Mine gets a lot of sand in it down here in South Carolina. I rinse it out 2 times a year, after we make trips to the Outer Banks of NC. I also run a sprinkler under in for while after those trips.
I got some of these in some of the frame holes.
https://www.amazon.com/dp/B00TZ7C8RC/?tag=wranglerorg-20
fixed the link.
I got some of these in some of the frame holes.
https://www.amazon.com/dp/B00TZ7C8RC/?tag=wranglerorg-20
fixed the link.
Last edited:
A couple small holes will not weaken anything...I do this all the time with boat trailers, because for whatever reason folks think that rectangle tube trailers are way better than hot rolled C-channel....until they rot. The important part is not the hole, but dressing the hole after it's drilled. This can be difficult, because when you drill a hole, you typically raise a substantial burr on the backside...and if it's not accessible, it's hard to get any sort of coating on it.
I use a cogsdill deburring tool like this https://www.amazon.com/dp/B001F8U7CW/?tag=wranglerorg-20 to get the backside cleaned up, and then a shitty artists paint brush with some POR15 to coat the newly drilled/deburred bare surfaces, and things tend to last a very long time after that.
If you're not in a salty climate, I wouldn't bother screwing with it...you'll be fine.
I use a cogsdill deburring tool like this https://www.amazon.com/dp/B001F8U7CW/?tag=wranglerorg-20 to get the backside cleaned up, and then a shitty artists paint brush with some POR15 to coat the newly drilled/deburred bare surfaces, and things tend to last a very long time after that.
If you're not in a salty climate, I wouldn't bother screwing with it...you'll be fine.
Thanks Tom. I just ordered a set of these. Now this makes sense to me. One thing Newer Mexico has lots of is flying dust. I fact I was thinking of using my compressor and running the hose into one of the side frame holes to just blow the dust out through the other side holes. I think I'll try that and see what it does.
ChrisTJ the froggy
Member
I want to thank you all for this thread. It answers many of my questions about holes in the frame and how to make them !
And the cover may be a very good solution to minimize the instants of mud...
Fixed it for ya:
https://www.amazon.com/dp/B00TZ7C8RC/?tag=wranglerorg-20
I swapped in an '03-'06 frame that has those front skid holes I won't use, so I just drilled a couple of matching 1/2" holes just in front of the rear LCA mounts. Now it has drain holes at both ends. Look at it this way, there are tons of rotted out TJ frames with the center skid bottom falling apart and big chunks missing by the rear LCA mounts and you don't see the frames colapsing, so a couple of small centered drain holes is a non-issue and better than the alternative frame rot.
MountaineerTom
LJ Enthusiast, Retired USAF Weapons Loader
Supporting Member
Ride of the Month Winner
MountaineerTom
LJ Enthusiast, Retired USAF Weapons Loader
Supporting Member
Ride of the Month Winner
I ordered one set. There were 4 plugs. There are more holes on the inside of the frame but I didn't put any in those.
LONGJP2
TJ Expert
Since it wasn't mentioned in this thread, I think 1/2" holes (front and rear) are recommended and considered completely safe.
The 05/06 (maybe others) have holes near the front control arm brackets. I matched those in size and placement near the rear brackets.