Calgary Jeep Association
4x4 Related Groups => Tech Talk => Topic started by: Jaguar on May 05, 2006, 10:39:35 PM
-
I am looking to mount a rack to my TJ, and I was wondering if drilling a few (2 more) holes into my roll bar would weaken them too much..... This is how I plan to mount it....
(http://www.telusplanet.net/public/jaguar17/cja/rack.jpg)
I will be attaching flat steel to the botom of the rack (green lines), then securing them to the rollbars. I will be using the existing holes from my speaker pods to attach the front (they are kinda small, but should do the trick......... I hope lol), and for the rear I'll have to drill a hole on each side... I'm thinking maybe a 1/4 ish hole to really secure the rack to the rollbars. anyone see a problem with this?.... or have a better idea? :)
Thanks guys!
Michael
-
So you are going to drill a hole, and then tap it to accept a threaded bolt?
I dunno, I don't think it will weaken the roll bar, but I think it might be a weak attachment point. You would have a grade 5 bolt holding x lbs up, thru how thick a steel wall of the rollbar? Prolly 3/16 or .1875 inch, or thinner. For holding the basket up, I don't see it being an issue. If you have a cooler full of beer and ice up there, it will hold it up. But if you start down the trail the various lateral or horizontal stresses might tear up that hole.
(I know the cage isnt suppose to move, but its a stock cage, on a stock tub, with a stock frame, there is shifting. But more so of the supported load exacting its forces on the bolts, rather than the cage exacting its forces on the bolts. Or heck, maybe both *shrug*).
I personally would lower the basket in between the bars of the cage, and use a something like 4" flat bar as a backing, and three or four ubolts per side to wrap around the roll bar and the nuts on the inside of the plate.
Thats, the way I am going to do mine. This way its lower (by max 2"), and there is no compromising of the cage. And the torsion point of failure is not the attachment point to the cage but in the flexing of the basket itself, which is an easier fix than a torn hole in the rolltube.
I'm no engineer, maybe I'm over-engineering it. But that's what I think.
Your mileage may vary!
Good luck!
Chris
-
Use a couple of muffler clamps around the rollbar and attach the basket to them. No drilling and you can remove the clamps later and not have any extra holes.
Vince
-
Use a couple of muffler clamps around the rollbar and attach the basket to them. No drilling and you can remove the clamps later and not have any extra holes.
Vince
Now that's an idea!!
See, that's why we keep you around Vince! :lol:
-
Elsifer, thats pretty much what I was worried about.... Plus I hate drilling holes into my Jeep :)
Vinman, awesome idea!....Now why didn't I think of that?! lol. Thanks guys!!
-
I think It would be better to drop it down between the R B, like Elsifer said, using the muffler clamps. That is if you don't plan on having passengers in the back.
-
If you do drill holes you could always weld another smaller piece of tubing in the holes to keep the strength. I saw that in a JP mag somewhere.
-
Gotta love those mags, hu? :) I'm going to give the clamps a go first. I'm still going to need some kinda substructure to hold the rack up because it's not as wide as my R.B.s are... Rack's width is 39 1/4" while the R.B. are 43 1/2" inside.
(http://www.telusplanet.net/public/jaguar17/cja/rackspace.jpg)
I'm thinking of using my origonal idea, but instead of bolts, using clamps...
Thanks again for the help guys!
Michael
-
I think I ended up drilling some 1/2 holes in Joel D. cage when I mounted his rack. We went with a through bolt and some big arse washers bent to the contour of the cage on each side. I don't think he had any issues. He's since got a new cage.
(http://i26.photobucket.com/albums/c149/Rebuilt98/100_0759.jpg)
(http://i26.photobucket.com/albums/c149/Rebuilt98/100_0757.jpg)
(http://i26.photobucket.com/albums/c149/Rebuilt98/100_0760.jpg)