short shift is stiff too
 

This weekend I installed a factory short shift as well as a new cup bushing at the base of the shift lever for good measure.

The shifter is now very stiff when I try to move it forwards or backwards. Side to side is fine. Is this normal? Should I just live with this untill it loosens up or should I take it apart file down the sides of the the lever arm near the pivot point and reinstall.

As background the trans was shifting well, for a 915, before the short shift just a little bit vague in its feel. The tranny has new swepco, the linkage has new bushings and the shift coupler is a new stomski (sp?) Every step along the way has led to slightly better shifting of the original trans with 120k on it.

So whats your advice, live with it a while and let it loosen naturally or take it apart and file untill perfect?

Short shifters are stiffer. That's part of the trade-off since you are losing some of the mechanical advantage of the longer lever arm. It's also tke reason some people don't like them.

Did you grease the ball cup bushing before bolting down the shifter assembly?

I noticed the housing (rectangular box thing) that the arm goes through, on the ss kit was bowed in. So, in affect, it was tight on the arm, so it would make back and forth movement stiffer. And I mean stiffer even out of the car, just sitting on the bench. The stock box (which was two pieces) wasn't like that. So, I stuck a big screwdriver in the ss box and spread it out a little. I did it with the arm in and the c clips attached so I wouldn't spread it too far. Loosened it up a lot. Still stiffer (even on the bench) but I prefer it so it forces me to shift a little more slowly. Much better than missing a shift a launching something. :(

I hated my short shift kit for the first two weeks after installing it in my SC. I got used to the increased effort and now I like it alot. It is much more precise. Still a pain to shift into fifth. Have to really push past the detent and make sure you are over on that plane or you can catch third by mistake. Careful not to over-rev.

Cheers,

Geoff

Thanks for all the advice, you guys are smart. I especially like what Chili suggested. It's a lot better then what I was going to do.

The tightness comes from the lever being so tight in the box. I was going to file down the lever but it makes so much more sence to simply spread the box a litttle instead. I didn't think of that because I like doing things the hard way.

I've heard different things about the factory short shift kit and debated getting one for a few weeks. Some people like them, some people say it is more "notchy" and you don't have as much control. Since mine isn't working properly yet I don't have an opinion. I get the feeling that once it's adjusted it has the potential to be nice, we'll see. If this doesn't work I'm saving my pennies up for a wevo.

One thing I've learned is that you can't just install the short shifter kit. It has to be fussed over a little before it gives the amount of drag you like.

Gerard,
This page describes some tips on improving the tolerances in the 915 shift housing:

http://www.seinesystems.com/ShiftHousBluPrint.htm

Belt sanding the OD of the shift lever is a more accurate method of controlling the interference fit between the lever and the fork (rectangular metal box). You don't want excessive slop in the shift housing nor do you want the shift housing to increase the shifting effort.

Sherwood
www.seinesystems.com

I just got rid of my short shifter. I first had a hard time to get used to the very short gear lever. But once I got over it I started to like it. Then the shifter developed this superanoying rattle. It was a resonace on decel in 2nd and 3rd. It drove me nuts. Rather than tinkering with the tolerances I replaced just the lever with the stock one and removed the shim plate under the housing. It took 3 minutes. I noticed the bend rectangular box which I left in there hugs the stock lever much tigher. No more rattle.

I have heard people saying that a 915 is simply not designed for a fast shift. I rather take the longer throw (thus shifting two tenth of a second slower than having a rattling short shifter that puts more stress on the synchro's. That's of course only IMHO.

Ingo

Just a thought but you didn't happen to position the tang that hold the rod bushing below the tunnel rather thatn on top. On the first one I installed I did that and while it is difficult to get the bolts started it is possible. It then tilts the bushing downward which binds on the shaft. When I figured it out I felt really stupid but then I did my next one on my 79 and the PO had actually fabricated a perfect little block of wood with 2 holes in it and used longer bolts because he too thought the tang went under the tunnel rather than on top! Anyone that knows what I am talking about will think this is really funny. I spent over 2 hours trying to start my bolts.

"....It was a resonace on decel in 2nd and 3rd. It drove me nuts. Rather than tinkering with the tolerances I replaced just the lever with the stock one and removed the shim plate under the housing. It took 3 minutes. I noticed the bend rectangular box which I left in there hugs the stock lever much tigher. No more rattle."

Ingo,
This sounds like a WM short shifter. The reason why the shift lever rattles is because their shift lever OD is 19mm. The factory lever is 20mm, a much better fit. However, in some cases, it's a little too snug, hence the adjustment that corrects this.

Damomma,
Are you referring to the Target short shifter? They provide a spacer for the shift tube to compensate for the longer lever attachment.

Sherwood

Great suggestions and tips, thanks to the board I have now "blueprinted" my short shifter.

This was a very satisfying job, I carefully filed and sanded the shift lever untill there was NO drag on the fork but NO play as well. I wanted it this way so I could feel if the shift lever was hanging up during the shift. I don't want to mask any resistience at the tranny with a stiff shifter. I don't want to force a shift if it isn't happening for some reason.

I also positioned the tang that holds the shift rod above the tunnel but wasn't sure this was correct untill you guys pointed it out to me. There is a notch under the shifter assembly that suggests that the tang fits above the tunnel but if there is room for missunderstanding, I'll missunderstand it.

So, after two hours of fileing how does it work?

Much better. The short shift is a little less vague but a bit more notchy just before it engages the gear. With no stiffness in the shifter at all you can feel the shift better and I believe I'm less likely to stress the tranny this way. The shifting isn't faster but it does feel more mechanical, less sloppy.

However, a 915 is a 915. It still takes a little longer to go from 1st to 2nd and speed shifting still seems out of the question.

I would recommend that anyone with a factory short shift read the blueprinting article and tailor their shifter to their liking. It's easy to do and the results are immediate.

Thanks all.

I believe you are right. But I simply didn't feel like tinkering with it anylonger. Maybe I could have put a shim onto the shaft going through the fork or bend the fork even more. I also noticed that 1/4 inch shim under the shift housing lifted it up too much. It appeared the ball of the lever with the ball bushing did not go fully into the bucket of the rod in the tunnel.

But oh well, with the stock setup I now can reach the lever again without my arm extension......

Ingo

Sherwood, I was refering to the OEM short shifter.

Hello
New to the 930 turbo. Previous 993 owner. I replaced all of the bushing on my shifter, but I still have some play on the shifter when moved left to right. Can you adjust this clearance by adjusting the threaded pin locknut? Or do I need to bend the fork box in.. Thanks in advance..Al

Allan Caldwell (PCA Tech) did a great article a year or so ago on the physics associated with short shift kits. I can't remember the exact date it was in Pano but the bottom line was essentially leverage. Less length of the lever=greater force required.
You might fire him a note (PCA.org) and see what other tips the article might have for optimizing.

I installed a factory short shifter on my reasonably well shifting 100K mile 915. I had to have the trans rebuilt within 5K miles. The wear on the syncros accelerated rapidly after the short shifter install.