How-to: DIY Short Shifter
 

DIY short shifter

If you’re cheap like me, have more time than money on your hands, and like making stuff, this might be of interest to you. This is a basic description of how to go about making your own short-shifter. A real, altered fulcrum type, not simply hacking off the top threaded bit (although we’ll do that too!) Otherwise, Mazdatrix offers a very nice piece for a reasonable price. However, if you’re resourceful, and have access to some basic tools, you can do this for under $25. The usual disclaimers apply here – I’ve only been using it a short while, and don’t expect it to last 100,000 mi. My guinea pig is an S4 NA, other models may have unexpected quirks.

The basic premise is to raise the fulcrum point of the shifter to decrease the throw between gears. This necessarily increases the ‘weight’ of the throw slightly, as you have less leverage in your favour. See the Mazdatrix website for a picture of what parts are involved.

You’ll need a shifter (I recommend you find a junkyard spare to perform the surgery on), a piece of flat aluminum plate ½ “ thick at least 3” square, a short piece of 1 ½” dia. “thick” walled aluminum tubing, a 3/8”-13 thread tap, a short piece of 6 mm rod or a ¼” roll pin, some red (high strength) threadlocker, 1- 9/16” (40mm) holesaw, hacksaw, drill, drill bits, cutting tool oil, jigsaw & metal blade . The metal you can probably scrounge from a metalworking shop or supplier. Also, you’ll need a piece of 3/8” threaded rod (I cut down a stainless steel carriage bolt) about 2” long, and three M6 x 25mm bolts for the top boot / plate. Optional parts, depending on condition, are the shifter bushings and the shifter boot / plate.

The basic modification is as follows. You’ll make a ½” spacer to sit on the ledge inside the turret and raise the seat for the lower bushing up. A ½” plate spacer will fit on top of the turret and raise the top bushing and boot / plate a corresponding distance. You’ll extend the reach of the small ball at the end of the shifter with a piece of threaded rod. Simple, huh?

1st – the top spacer. You want to make a ‘donut’ shape, 40mm hole on the inside, and around 70mm outside diameter. Layout from the center point the diameters, and use a gasket or the top plate & boot to mark three bolt holes. Drill out the center hole – slowly!! Use lots of cutting oil, and take a break to let things cool once in a while. You want this hole to be pretty smooth and concentric with the turret hole, as the bushings will be seated inside the diameter. Next you’ll cut the outer diameter with the jigsaw, and then mark and drill the mount holes – ¼” dia. is fine and will allow a little ‘wiggle’ for alignment. Then set the plate on the shifter turret and secure it with the bolts. Carefully mark on the inside of the plate right above the locator pin in the turret. You will need to drill a hole for a new pin through the edge of the plate. This is tricky. The hole must be aligned radially, and the edge of the drilled hole will just touch the edge of the plate. You’ll be locating the new pin 13mm higher than the stock one. If you have a 6mm rod, a 15/64” dia. hole is perfect. If you use ¼” pin, you’ll have to file the groove in the shifter ball a little wider to accommodate. Secure your pin with loctite.

2nd – the inner spacer. You need to cut off a ½” slice of the pipe as accurately as possible. I borrowed a large plumber’s type tube cutter, and cut a slice slightly thicker. Then I filed it down and sanded it with silicone-carbide paper taped to a flat surface until it was exactly as thick as the spacer. With that done, cut a slot through the ring, and spread it apart until it is a snug fit inside the turret. You should end up with enough of a gap to clear the old locating pin.

3rd – the shifter. Measure from a reference point on the underside of the fulcrum ball to the fattest part of the little ball and record the figure. Then start by drilling a pilot hole, around 1/8” dia., through from the bottom of the small ball up about halfway into the fulcrum ball . Keep it as perfectly centered as possible. Enlarge the hole with a succession of drill bits, when you get to the 5/16” bit, the little ball will be freed from the extension leg. Cut off any remnants of the leg. Use liberal amounts of cutting oil and tap the both holes with the 3/8”- 13 tap. The tricky part is securing the little ball for threading, holding it tight enough without scratching it up. Try a piece of rubber mat and / or blocks of wood in the jaws of the vise, and go at it gently. Screw in the threaded extension into the fulcrum ball, then thread on the little ball until it is the measured distance + 13mm from your reference point. Use loctite on final assembly. Lastly, cut ½” (or more if you want to lower it) off the top of the shifter to bring the knob height back down to where it was before.

The finished piece isn’t pretty, so hide it back in the shifter turret! You might want to use a little RTV or another gasket between the plate and the top of the turret. Enjoy your budget short shifter - I’m now measuring the throw from neutral into 1st at 1 ¾”, down from around 2 ½”.

Curtis
'86 GXL autox'r

damn good writeup, could you provide some pics of the parts and stuff drilled? i'm thinking this should be archived.

pics would be great!

The original owner of my car hacked the thread off the top of mine and rethreaded it. It's a lot better than the three foot tall unmodified shifter.

im pretty mechanically inclined and that got me confused. some pics would definately help.

woah! Nice!

I think I've found another project :)

OK, here's a pic of the three pieces you'll make.
The shifter is from an '89, it has a bushing in the groove (the S4's don't have a bushing). Threaded rod replaces the short 'leg' of the original.
The split ring, same height as top plate.
The 1/2" top plate: the pin is flush with the bottom of the plate.
Good Luck;)

Curtis
'86 GXL autox'r

sounds good. as for the three holes drilled in the dohnut, does it matter how far they are from the inside?

Great idea, How big was that pipe that you made the split ring out of originally, and what was it made of, aluminum?

John

https://www.rx7club.com/forum/attach...postid=1425908


Cool... Just have to be sure everything lines up.
Though it isn't actually too difficult, I'm not too sure many people will be attempting this.
Here's a hint (since I don't have the time) make up a few of them and sell them here. Short shifters are about 200 bucks. If you can find a few shifters to modify, or have people send you theirs, you could sell them for a good chunk cheaper than the others out there.

There is a difference between the S5 and S4 shifters though. I can't remember what it is though.

In addition to the bushing, the threads are smaller on the S5 shifters.

why don't you add some pics and contribute to the "how-to" for the www.fc3s.org

Would you guys buy a short shifter like shown in that pic for $79 new?

I don't have the means to do a production run but I was just thinking how easy it would be to program a CNC lathe to bust out those new shifter stalks, and then contract out the other small parts. If someone did a run of 1000 of those, the unit cost would be low enough to make $79 a realistic price. You know, make up for small profit margin with volume, like with burgers and fries :)

So who would buy one for eighty bucks?

...not 1000 people...

It's missing the hardware and the gaskets. add on the missing parts and this puts the whole thing up near the price of the mazdatrix unit. I would rather have the mazdatrix unit since I know it works and their products are usually top notch

i just brought a S5 part car, i swap the shifter to my S4
i haven't try driving my car yet.
so i don't be able to shift gear???
should i change it back to my old shifter?
the old one is kind of lose.

From the original position... how much does it extend the lil ball from the big ball?

kinda stupid to ask, but anyone ever made a Mastercam program for CNC maching a short shifter or would I need to do one myself?

Im drawing one up on autoCAD, but havent finished yet due to lack of a vernier... boo

I need a web page where ,I can see much pictures of mazda 89 (second generation) help please

rosesgirl@hotmail,com

I'd buy one for $80! :)

i will find out shortly if this is going to work. i am getting two to start made out of aluminum. the throw will be about 2 1/2 inch. dont know cost yet. but its just the shifter it will drop in. its for a s4 though. i am allso getting the coolent tower filler thingie made out of aluminim also. you know the thing thats plastic thats $60 from the dealer. if ne one would want one ill get pricing and post them soon.

ej

O.K., I see something has obliterated many of the dimensions and punctuation (apostrophe's and inch marks) in the original post. So, here's the missing bits:

Flat aluminum plate is half-inch thick, the donut you cut will be about 70 mm dia., so the plate should be about three inches square.
Aluminum tubing for the split ring is one-and one-half inch diameter, you cut off a half-inch slice to match the plate thickness.
The substitute for the 6mm pin (if it can't be sourced) is a quarter-inch dia. roll pin, and alter the shifter groove to fit it.
To get the shifter knob back down to original height, cut off half an inch from the top of the stem.

Nice writeup, I hate the feel of my shifter, maybe I will try this out, thanks.

I made my own cheesy short throw shifter... I took my old shifter and took a propane torch and melted the rubber stuff out of it cleaned it with a wire wheel and put a crappy shift knob on it... To avoid rattling you will probably need to JB welb the shift knob or have the shaft threaded... It isnt the right way probably but it seems to work but it rattle and my sift knob is always loose. Just my 2 rotor's worth.