The quest for the ultimate/affordable TSX short shifter.
For many years now I have been waiting for a company to come out with a full short shifter solution for our cars, something that uses the OEM plastic base, and just changes out the shifter. It would be more economical for the manufacture, a higher quality for the buyer, and it would use the dependable plastic OEM base. The Mugen version is an inch shorter by the knob, and does not change the leverage points, and the price is ridiculous. The CT one could come loose, and I just don’t plain trust no set screws and glue, and again expensive for what you get. My background is mechanical engineering and I have the CAD/CNC tools to do most custom projects, so on I went with this one.
To start I took my shifter assembly out of the car and studied it for a bit. I found the design to be simple and impressive. The engineering that went on this piece was high quality, simple designed, and cheap to produce. I took a few key points off it and moved on. Next was the measuring of the part using high end Starett comparators. The bottom tip of the shifter was of most importance as the plastic ball that goes over it needs to roll smoothly. Another key measurement is the big center ball that the shifter uses as its central leverage point. With my measurements taken and rechecked I moved on to machining open the OEM shifter.
First I noticed that the back end of the central ball was pressed in. The spidering effects and the dimple gave it away. This is what Honda used to attach the ball to the shifter. Simple and effective!
To release some pressure off the dimple and to slide the ball off easier I center drilled the center of the dimple out. As this point would usually have the most clamping pressure.
Next I moved on to drilling the dimple out, and pressing the ball off the shaft.
What I discovered was again impressive. This hole time I thought the dimple is what kept things intact, but I was wrong. This is where research pays off as I realized that sideways motion could loosen up the pressing. Honda used straight cut knurls on the shifter and ball. When mated they allow each other to pass through each others channel to stop sideways motion.
Next was the designing stage. The curve in the shifter that Honda puts in our shifters is for ergonomics reasons that I can’t explain. The curve makes the shift knob be about .200” away from the driver. If anything you would want the knob to be closer to you, especially when shifting into 5th and 6th. Think about the EG/DC shifters and how they curved back towards the drivers hand for closer shifting. This design might be an inherited design from the JDM cousin that they were too lazy to change. Worried about how it would stick out I ran to the car with an assembled straight bar and the OEM ball. I could not tell at all. Put the center consol back on, and the shifter looked straight and right in the center. Mugen users can verify this as well.
My design is a 3 piece 303SS assembly that will be either tig welded or laser welded together. Here shown before assembly
Here shown after all welded together and ready to replace the OEM piece.
The next stage was important. Using GibbsCam, I used the CAD files I designed earlier to program the path of the CNC. With the help from a machinist/friend at work we got the thing ready to roll.
After the programming we prepped the CNC and loaded the first bar in the chuck.
After running the CNC the finished product looked like a beautiful part. Measuring confirmed that we were within .0001”. Amazing!
Here is a little clip I shot of the CNC running.
Overall 3 test pieces are made. The back end will be done shortly then I can move on to the ball and side lever.
More to come of the finished product! This was done to generate some interest in the TSX/Accord community in the mean time, and get some feedback to whether this is a wise choice to put this product in production.
Thanx for looking. Bardi.
As of 12/13/13 I have decided to put the scattered information on this thread on the first page. The web pages below are two very well written installs by two forum members. Please use these instructions to install the shifter:
Just a little clip and instructions on how to install the new hardware:
1-Lightly coat the body of the shoulder bolt with grease (It helps spin inside the hole better when you shift).
2-Make sure no grease ends up on the threads of the shoulder bolt. Clean threads with alcohol asap if this happens! Appling blue/red thread-lock on the threads is recommended if you have some, but not necessary.
3-Coat washer and mating pocket of plastic crank arm with grease.
4-Tighten as video shows.