Garagistic M6X Swap Guide- Shifter Mechanism

In the shifter section, I will talk about the option that I went with regarding the 6 speed transmission, but I’ll discuss the 5 speed as well, since it’s so similar and the process to build/shorten the assembly is virtually identical. Since I got this specific 420G transmission, I had to use the shifter mechanism you see in Figure 124. It’s simply different hookups on the transmission itself.   

22.2.1.1 TOOLS REQUIRED

Table 17

Socket	Wrenches	Misc.
13mm Socket		Wire Snips
		Long Flat Head Screwdriver
		Contracting circlip pliers

 

22.2.1.2 TIME & MONEY

- 2.5Hr & $20

22.2.1.3 INTRUCTIONS

I had to shorten and weld NOT ONLY the carrier, but also the shifter selector arm. This is relatively tricky because you must measure 5x and cut once. Word to the wise: Do this after the engine/tranny has been dropped in. I can’t imagine how you would do it without any frame of reference.

Note that I can’t tell you exactly how much to shorten it, but I can probably ballpark it. Remember that the 5 speed shifter will be longer because the ZF Transmission itself is shorter.

See below for the realoem snapshots of the shifter pictoral.

As you can see in Figure 126, you need to shorten both the selector rod AND the carrier.  

1. Cut the carrier in half. Remember you’re shortening it.

2. Have a friend sit in the driver seat. You under the car with both halves. Hold up both halves together to length so that the carrier sits center in the through hole. Forget about the shift rod for now. You can overlap with the first half if you are afraid to trim for now. There will be about an inch or two (depending on engine position) of your shifter plate. Have your friend in the driver seat tell you when the shifter would be in the center of the hole. Then, make a mark, take it apart. And weld it together. Now for the selector rod. This is very important how you do this because if it’s not right, you will have problems shifting and you’ll rip your shift boot.

a. Too short – 2nd and 4th gear will hit the center console

b. Too long – 1st, 3rd, 5th gear will hit the center console

c. Just right, the neutral position of the shifter will be right in the middle of the console and all gears will shift perfectly, including reverse.

I replaced all nylon bushings. They are yellow and look like thin plastic washers. I replaced 4 of them. It was tight, but then again, tight is good. It means minimal play in the shifter. I also used AND highly recommend a short shift kit to prevent any scraping of the shifter in the console, ruining my shift boot. 40% reduced throw, so I was happy.

Now in order to retain the shifter mechanism to the frame of the E30, you must think smartly about it. The first iteration of this, I had no rubber bushing in between the shifter mechanism and the body (highlighted by Yellow circle in first picture) . I bolted it tight! Bad idea. Turns out that under coasting conditions, I could shift fine, but hard acceleration or turning situations I forgot that the tranny/engine DO MOVE, so having the shifter bolted to the frame was a bad idea. That’s why I decided to put a rubber bushing. That allows about ¼” to ½” of play for the tranny to move around under hard acceleration. Now I can easily shift under any circumstances. I will leave this to your imagination. It’s not difficult if you can be creative and have a lowes or home depot near you. I initially ruled out using the actual BMW part. I just didn’t think it would be compatible, but it most definitely could be.

In retrospect, you can weld/fabricate your own shifter mount/mechanism however you like. You will definitely need a stock selector arm and shorten it. There’s no question about that. That is simply a cut, shorten, and re-weld application. This is a pivotal step though because the length of this selector arm dictates the position of the shift knob when in neutral. You want it completely centered.

INSTALLATION:
The installation of the shifter should look as shown in Figure 128 and Figure 129. Note that I later installed a UUC Short Shift Kit and Double Sheer selector rod (DSSR). It looks and feels amazing, but the pictures are standard for most shifter shortening.

You have the option to upgrade your shifter bushings to Delrin bushings by Garagistic as shown here:

Figure 130 shows the bushings and how useful they can be to enhance your ride. You can even get a rear delrin bushing for the rear end of the shifter mechanism to round out your shifter feel to a noticeably sporty feel.