Jeep TJ Rear Bumper Project

Page 2

Placing the arm back in place we fashion a latch plate to secure the arm assembly.  We recommend using 1/4" plate for this but nothing less than 3/16".  The plate is secured to the arm with a clamp in the proper orientation and the arm is placed in the position it should be in when closed.   The latch plate is then welded to the main bumper.  Tack the plate in place first then move the arm out of the way to finish the rest of the welding.   We then cut a 2" x 3" piece of scrap plate to cap off the end of the arm.

 

We then cut a 3 1/2 length of Class III receiver hitch material and place it in the center of the bumper tube. Making sure the face of the hitch tube is flush with the face of the bumper we weld the hitch to the bottom of the bumper.  Be sure not to get to ahead of yourself and forget to drill the 5/8" hitch pin hole.  We have been asked why we don't recess the hitch up into the bumper for better departure angle and the answer is that you wouldn't be able to put the hitch pin in!  In real world use we find that we just don't have a problem with departure angle with the hitch below the bumper like this.

 

 

Main Latch

Gas Can Mount

With the hitch welded on we then cut 1/4" plate to make bolsters for each side of the hitch and to give it a more built in look. We don't worry too much about the quality of our cuts on the bolsters where they meet the bumper or hitch as they will be consumed by the weld anyway.  Once we have both bolsters welded in we then use a grinder to smooth down the welds and make everything nice and flush with the face of the bumper.  Fill any small imperfections with JB-Weld and sand smooth before painting.

In the past due to the fact that we didn't have a tube bender we had used 2" square tube, miter cut and welded to form the tire hoop for the swing arm.  We now have a tube bender but don't worry if you don't because you can simply go to www.jeeptubes.com and order a pre-bent tire hoop tube.  The reduction in time spent welding and grinding as well as the weight savings are incredible!  Jeeptubes.com leaves the tube a little long so that you can customize, so minor trimming will be necessary.  The tube should be centered on the swingarm and it is very important that the top of the tube measures 15 1/2" from the top of the swingarm.  This is a spacing issue for the gas can hold down brackets that get fabed up later.

Now we cut 2 lengths of  1 1/2" wide by 1/2" tall U-channel for the gas can mounts.  the channel will provide the mounting location for the latches that actually clamp down the cans from the top. 5/8" holes are drilled in the center of each channel about 3" down from the top to provide access to mounting screws that are part of the latch mechanism.

Now we cut another piece of Class III hitch material approximately 8" long and drill two 5/8" pin holes through it which will be our tire receiver mount.  The purpose of the two holes is to provide more flexibility for adjusting the tire mount for different wheels with varying back spacing.  Getting the right combination of length of the receiver and the tire mount is hard to do and you cannot get the tire to fit in tight to the hoop and be adjustable enough to slide out for the gas cans.    At best you can expect some space between your spare tire and the tire hoop bar if you want the ability to install cans when the spare is slid all the way out.  We use a 1 3/4" hole saw mounted in the drill press to cut out one corner of the mount to fit around the hoop tube.  The tire receiver mount should end up being flush with the back side of the hoop. A small plate of steel is then cut and welded to the back of the mount to close off the opening and flush it in with the tube.  The mount should be welded to the bar in a 1 or 2 degree up angle so as to allow for a little bit of droop in the tire mount that slides into the receiver.  Once welded to the bar we use the remainder of our U-channel to add a brace from the top of the swing arm to the bottom of the mount (picture at right).   If you stand back and admire your work for a minute you might notice that the tire receiver and the hitch on the bottom of the bumper don't center over each other.  Don't worry this is normal.

The main latch for the swing arm is the De-Sta-Co #344 which we order from Reid Tool, (Reid tool #TC-344) and the latches for the gas cans are the #TC-351-B.   We drill 4 holes for the main latch and tap them.   Button head bolts look really good and we always like to use stainless hardware where ever we can.

2 pieces of 1/4" wide angle iron is cut at around 8 or 9" in length and welded to the face of the swingarm near the bottom so that the angle faces up.  The angles are centered under the U-channel we installed in the step above.  This provides the lower mount for the gas cans.  The lip on the bottom of the cans is set down onto the angle and the handles are cinched down using the latches above.

Rear bumper build Page 3