Transmission modification

[Quiny]

I just torn down my 5MT and was wondering if anyone has attempted to modify the shift rod. It looks like it would be pretty easy to shorten it up to prevent the linkage from being so close to the rear fiberglass. Even if I didn't machine the shoulder back I could still re-drill for the spring pin and gain 3/4 of an inch. Has anyone done this yet and if so did it work out well?

[Jaime]

We talked about it in another thread. The rod is supported by two ball-cage bearings, one of which is at the very back of the housing. The only low hanging fruit is to move the fitting closer to the trans body as you mentioned. Any actual shortening of the transmission will require figuring out a new bearing arrangement.

[CptTripps]

We talked about it in another thread. The rod is supported by two ball-cage bearings, one of which is at the very back of the housing. The only low hanging fruit is to move the fitting closer to the trans body as you mentioned. Any actual shortening of the transmission will require figuring out a new bearing arrangement.

Why would that be? If you take 1" off the end of a pipe, the other end doesn't know what happened. You're just re-drilling a hole and then you're off to the races. Right?

[RM1SepEx]

you could cut and redrill, I gained an inch by flipping the shift lever 180 degrees and welding it together. Photos on my thread, I also had to reposition the trans bracket. Yes you could rebore and drill to get more space, my way is easier

[Jaime]

Why would that be? If you take 1" off the end of a pipe, the other end doesn't know what happened. You're just re-drilling a hole and then you're off to the races. Right?That will get you an inch or maybe an inch and a half. Shortening it more than that is where the difficulty begins. There's about six inches that could be removed if someone was willing to do some serious engineering.

[Rasmus]

Watch what Subarugears does:


https://www.youtube.com/watch?v=RXEUSVSpGHg

[Mechie3]

I've prototyped one version. It looks like Subaru Gears version where the shift shaft is left intact. It cuts away a lot of the excess, but not all. There's another version I want to try but I only have 1 spare housing at the moment. There is someone who has cut off a lot of the housing and made a separate shaft support, but I have no data on longevity. The forces put onto the shaft are off center so it creates a torquing moment. The farther apart the bearing are, the less radial load they take. The closer together they are the more load they need to support which could (or might not) cause binding or excessive wear. They used a simple bushing on their support for the chopped down version

. The factory bearing is a funky linear rotary bearing. Instead of balls that run in an axial track for linear motion the balls are held at a fixed spacing in a cage. It looks like a material handling conveyor wrapped into a cylinder. The Subaru bushing goes one step further and allows the entire cage to translate fore/aft. The bearings are a bit expensive. $75 ea at mcmaster carr or around $50 on Amazon. Search for "linear rotary bearing".

Partially done first prototype:

http://i.imgur.com/8mOK3iV.jpg

[RM1SepEx]

http://thefactoryfiveforum.com/showthread.php?10649-RM1Sepex-Build-Thread/page14 post 543 includes photos for an easy inch if you have a welder

[Boog]

Could an 'access hole' be cut in so the shifter arm is placed/supported between the two original bearing locations? This would allow any 'tail' to be removed.

[Mechie3]

The one bearing is only about 1/4" from the end of the til so you would t save much. There's also the issue of sealing it so oil stays in and dirt stays out.