T-90 BACKUP LIGHT INSTALLATION
I finally got tired of having people try to run over me while I was backing out of parking lots, so I decided to do something about it this week. I noticed a while back that the replacement transmission I bought for my truck had areverse switch boss molded into the shift tower case. I figured that it would be easy enough to drill a hole in the boss, tap it and screw in the switch. For some reason, in my mind I visualized that all of the shift towers were equipped with this boss. I went to NAPA and researched their catalog and found a reverse switch for Kenworth and Peterbuilt trucks. Wow, if it was good enough for those guys it should be good enough for my Willys.
With my newly purchased switch in hand I headed home. I didn't even go in the house when I got home. I went right to work pulling my shift tower. You see the shift tower in my truck was in better condition than the one on my spare, so I wanted to modify it instead. Darn, it didn't have the boss. I went to look at another one I had in the basement (It was Frank Wood's) and it didn't have one either. This left me in a bit of a dilemma. You see, I had told some folks that I thought they all had the bosses and that it should be an easy mod for everyone to do. Some of them had gotten excited about adding these switches to their trucks andů well, I guess you can see that I wanted to show it could still be done.
I decided that it shouldn't be that hard to mount the switch in theround boss. My first problem I ran into was the switch has a 9/16" thread. I had a bit of trouble finding a tap for this, so I decided to buy a different switch with a smaller shaft. After 2 hours at NAPA and 15 trips into the back we decided that I needed to stick with the switch I had. NAPA didn't have the 9/16" tap but they could order it for $7.00. It uses a 33/64" drill bit that cost $18.00 to drill the hole for tapping. You do the math, 32/64" is 1/2" + 1/64". I figured I could wallow the hole out enough to get that extra 1/64" of clearance with my previously owned 1/2" drill bit and save myself $18.00. I ordered the tap and decided to use my 1/2" drill bit. As it turns out this was not a good plan.
With the hole drilled in the rounded boss I had to try to thread the top two opposing edges of the hole instead of all the way around. This caused the tap to keep stripping out of the hole. In addition I didn't have the hole drilled out large enough and this caused more stripping out of the threads. By the time I got down to the bottom of the hole I only had two solid threads in the hole. Bummer. When I screwed the switch into the hole it didn't feel very solid on top of the rounded boss so I decided to grind the top of the boss down flat. This turned out to be another bad idea. Once I had the top of the boss flattened I screwed the switch in and hurrah, it was tight and secure. Unfortunately, it was down too far and wouldn't allow the shifter to move into reverse. Second bummer. "Enough of this" I said to myself, I'll just use the flat-bossed tower instead.
As you could see in the earlierpicture, it drilled and tapped out quite well. I screwed in the switch and it shifted great. Now my only problem was that the previous owner of this tower had cut the shift lever off about 9" shorter, so I would need to swap the shift levers. As I was taking the second shifter apart I realized there was a flaw in my plans again. It seems the spring for my original shifter was much further down in the tower than the flat bossed one. What gives? When I compared them together I realized I was in trouble, the round-bossed shift tower was much taller than the flat bossed one. I'm not one to give up easily so I decided that maybe I could modify the longer shift handle to fit the shorter tower. About 30 minutes later I realized that even if I could modify the shifter it would cause the shift-throw to be way off. Back to the drawing board.
I decided it was time to get back to the original shift tower and make it work. I ground the rounded boss down a little more, greased the shift rod and slid it into place and then filled the hole and surrounding area with JB Weld. I let it cure for 12 hours in the sun. The rod prevented the JB Weld from running into the shift rod tunnel (Caution do not let the rod, stop with a detent under the hole or it will not come out), and the grease prevented the JB Weld from sticking to the rod. Then I ground the JB weld back down flat and to the exact height I needed to activate the switch. I drilled the new hole, tapped it and screwed in theswitch. It fit great and worked wonderfully. I used some silicon sealant on the threads to make sure it would not back out. My transmission sits about 2 inches higher than it is supposed to so I had to slightly clearance the cover panel to prevent the switch from shorting out.
Now I needed to wire the truck and install the lights. I found a set of backup lights at Autozone for $3.95 a piece. They were plain and simple but I didn't need much anyway. I didn't want to drill any new holes in my truck because I felt it had enough to begin with. Instead I installed it in the oldPTO output hole. I decide one light would suffice and I was right it works great and I can see just fine.
I have heard some discussion of late about WARN Overdrive shifter installation so took a few pictures of how mine is installed.Top View Bottom View