How to build a lockable roof top spare tire mount (welding optional)

This is a "How-to" for building a roof top spare tire mount for about $30 + paint and lock. Sorry i didn't take pics during the process but should still make sense. The welding optional information is added at the end.

Tools
Welder, i used a small mig welder
Saw capable of cutting 1/8" steel, i used a 14" Chop Saw
Drill
1/2" Drill Bit
Drill Bit for the u-bolt holes
Grinder (if you want to clean u the welds, cuts, and holes), i used a 4" angle grinder with a flap wheel
Hand tools to tighten the u-bolts

Materials
2" wide x 1/8" thick flat steel, you'll need at least 28" long
6" of chain, and grab the two cut link pieces after the store cuts the chain
8" long x 1/2" bolt with appropriate nut and lock washer
1- foot of 1/4" thick round steel
2 - u-bolts 2 1/4" wide (center of bolt to center of bolt), should come with a small plate to span the gap between the two sides of the u-bolt and nuts
4 - lock washers for the u-bolts
4 - rubber strips approximately 1/2" wide x 2" long x 1/4" thick
1 or 2 - 1/2" bolts to weld on the top plate for lug location
If the u-bolts you get aren't threaded far enough as mine weren't you will need 4 spacers
1 - lock, i used a rubber coated one as its gonna be seeing a lot of weather

Fabrication
For the main mount i would check these measurements on yours to make sure its the same as i am not sure about other years. Make sure the roof rails are clicked in for measuring.

Ok, for the main piece i used 2" wide 1/8" thick flat steel and cut it to 21.5" long, drilled holes for 2 u-bolts 2.25" wide (enough to fit over the roof rail, i couldn't find ones threaded far enough so i had to use spacers) 15.75" apart, drill a hole in the center for an 8" long 1/2" bolt to slide in all the way to the head (i used the kind with the round head and make sure its threaded far enough), weld the bolt to the main piece.
http://i1108.photobucket.com/albums/...0241-1-1-1.jpg
http://i1108.photobucket.com/albums/...4-222212-1.jpg
Bottom of the main bolt welded to the steel
http://i1108.photobucket.com/albums/...MG0243-1-1.jpg


The only u-bolts i could find in the right width were too long, so i had to cut them down a bit or they would've hit the roof.


For the top plate i used the same flat steel cut to 6", drilled a hole for the main hold down bolt in the center and a hole 2.25" away (only for 5x4.5 bolt pattern) for a "lug nut locator" bolt that i cut the threads off of to slide in to a lug nut hole on the wheel. I would suggest two of these (one on each side of the main hold down bolt) because the wheel has the ability to move a little, not much due to the main bolt though. Weld the cut off bolts through the top plate and weld half of a link of chain with about 6" of chain in it (otherwise theres no way to get it in there later) to the top of the plate. I also added a little personalized xj letters, of course not required.

Top plate-top view
http://i1108.photobucket.com/albums/...MG0248-1-2.jpg

Bottom view with measurements
http://i1108.photobucket.com/albums/...4-224557-1.jpg

The "wing nut"
I used the appropriately sized nut for the main bolt and welded some 1/4" steel rod to the nut, then welded a half of a link of chain to one of the sides of the rods.
http://i1108.photobucket.com/albums/...MG0249-1-2.jpg

http://i1108.photobucket.com/albums/...MG0252-1-1.jpg

Then clean up all the welds, cuts, and holes with the grinder and paint all pieces except the threaded areas.


Installation
Place the main mount under the roof rails. Sandwich the roof rails between the main mount and u-bolts. I used some thin rubber strips in between the roof rails and the u-bolts/main piece so it would distribute the load as to not crumble the rail. Place the small u-bolt plates/lock washers/nuts on the u-bolts and tighten.
http://i1108.photobucket.com/albums/...CIMG0270-1.jpg


Place the tire face down on top of the roof rails with the main bolt going through the hub hole in the wheel.
http://i1108.photobucket.com/albums/...03184018-1.jpg


Then place the top plate on top of the wheel mounting surface with the main mounting bolt going through the center hole in the top plate and the lug nut locator bolts into the lug nut holes. Next put a lock washer on top of the top plate and spin the "wing nut" on the main mounting bolt. Tighten it down, the main mount will deflect a tad, just don't over do it or you'll bend it. Take your lock and lock the chain to the link half on the "wing nut".
http://i1108.photobucket.com/albums/...01174947-1.jpg

It could be done without welding but with more hassle.
No welding on chain=Not lockable
No welding on main mounting bolt=bolt would be loose when not tightened (and be sure to slip bolt in before mounting the main mount)
No welding on lug nut locators=slightly more movement from tire (could be resolved by putting something to fill the gap around the main mounting bolt inside the wheels hub hole)
No welding to make the "wing nut"=just using a wrench to loosen and tighten the nut


If I've forgotten anything let me know and hopefully i have the answer.:wink: