I was at the race track last weekend to watch a friend of mine, Sean, race. I enjoy the races and haven’t been in a while, so I thought it would be fun — especially since I knew someone racing.
To make a long story short, I didn’t get to see too much of Sean as he had some “technical difficulties” with his transmission and had to be pushed off the track after a half lap. Bummer. Actually, to be quite honest, this happened August 4th.
Of course, when stuff like this happens, I seem to be the one my friends bring their stuff to when it needs fixing. Ah, but I enjoy a challenge!
The problem was that the transmission got stuck between gears, first and second, and was jammed. Good thing it was in neutral so it could be pushed off the track of he’d have been in some real trouble!
Below is a shot of the completed repair. I’ve got to get my butt in gear for work this morning. As the repair will take a little explaining, I will get the rest of the pics together and post the repair, in detail, when I get home tonight. (Oh, the part I made is the aluminum housing for the shifter — but I’ll detail that later.)
The part itself was not overly complicated — but there were some challenges, to say the least.
First, I am not a transmission guy — I have a tranny shop “in the family”, so to speak, so I’ve never worried about the “hows” or “whys” of transmissions — I leave it to the professionals. Challenge number 1? Figure out HOW this thing works (or was supposed to work)! You can’t fix something if you don’t know how it works (OK, so that’s not entirely true, but it makes life oh-so-much easier!).
The second challenge was right behind the first. After figuring out how it worked, I then came up with a plan to fix it — but how was I going to hold it in my milling machine?
OK, a little info on the problem — there is a plastic (we’ll call it plastic, but it’s probably more like delron) bushing/cap that is threaded. This bushing/cap basically screws into the transmission and holds the shifter in place. The problem is the bushing is threaded metric, which my lathe will not do. So, the plan is simple — mill out the threads in the tranny and make a new piece that is press fit and held tight with a couple of 1/4″ x 20 screws. The next pic shows just how I managed to get it in my milling machine, straight and level — and it wasn’t easy! The second shot is a closeup, and shows the plastic bushing/cap.
1) The shifter was cut (as you can probably tell in the closeups of the shifter) to be able to get the boot and the plastic rings off/on. I should have “sleeved” the shifter when I re-welded it, but tried to make it look pretty, welded it and ground the welds smooth — mistake! These guys are pretty hard on their shifters! Sean broke it the first night he test drove it. It was easily fixed, and lesson learned.
2) There is supposed to be some sort of a plastic “clip” that goes in between the forks of the shifter and the linkage. It, somehow, keeps the shifter in the up position, so that you cannot accidentally shift into reverse. I have no reference for this part, so I have no idea how it works. No biggie, I’ll solve the problem another way!
What I did was simply weld on a little material on the inside of the forks to take up some “twist play”, and added a little material to the back of the “balls” on the end of the shifter which contact and move the linkage in the tranny. Basically, just making tolerances tighter.
Once everything was mating nicely, and was nice and tight, I had to now figure out how to get the shifter to stay in the up position so you couldn’t accidentally shift into reverse. (There is a small block on the right side (when looking through the end with the cap removed), that makes contact with the block on the shifter. When these two hit, you cannot go far enough left to get to reverse — you must push down, and then you will be allowed to move the shifter further left to go into reverse.
I started thinking about this problem around 8pm one evening and gave up on a few ideas hours later and went to bed. I woke up about 3:30am and had the problem solved — all I had to do now was figure out how I was going to go back to sleep until at least 7:30am!
The solution, although it took some time, turned out to be really, really, really easy. Use the boot that was already there, with a snap ring installed above it, as a “spring”. It worked perfectly! The boot kept the shifter up, while giving the perfect amount of springy resistance to be able to push the shifter down and left to find reverse (which I found out later they hadn’t been able to find before!).
PS – BTW, Sean had the car ready again to race last weekend (which would have been the 18th), so I went back out to watch — first lap around there was a tangle up and he bent the frame and had to sit out another night. I haven’t talked to him since, but hopefully the car is on the road to recovery and we’ll see him out there sometime soon!