Rennshift Installation (long), My experience in a 3.6 with a 915 Options

[PRS914-6]

My 915 has been shifting pretty good with a WEVO conversion kit. However, I am short and I have to reach for 3rd and 5th and I wanted a spring centered shifter. After reading for hours about WEVO shifters and the Rennshift and talking to both Hayden at WEVO and James at JWest I decided on the Rennshift.

The decision was arrived at by features. I liked the adjustability of the Rennshift. The main issues were the throw (20 or 30%), the moveable shift arm that can be moved to your liking and the adjustable motion stops. I think a 30% reduction is too much for a 915 since any reduction results in more effort to shift and the Rennshift is one of the few that allow less reduction. More isn't always better here.

I ordered the shifter from James and it arrived 2 days later (good service). I yanked my old shifter out and installed the new. I had to massage my clutch tube a little that collided with the shift mechanism but that may have been due to the custom shift shaft.

It's rather tricky to get the adjustments perfect but once done it worked pretty good. Unfortunately there is less bend in the Rennshift arm than a stock 915 shifter. The results were that the shift knob position in 3rd and 5th were in about the same position as the old unit despite the shorter throw. You long armed people shouldn't have issue with that.

I decided to move the entire shifter rearward and re-drilled the holes 1 3/4" back and shortened my linkage rod. This was a lot of work but worth the effort. The shifter is now in the perfect spot, no reaching at all. BIG improvement.

I struggled with the reverse lockout. I suspect that the WEVO kit may not use as much movement as a stock 915 in reverse. I gave up and added shims to increase centering action of the 3-4 plane. This worked great and I took the auto-reverse lockout completely out since I really didn't need it. As you down shift, it pops right in to the 3-4 plane anyway.

Driving.....
The feel is excellent and detailed. When shifting from 2nd to 3rd (not to be confused with a 901 pattern) one only needs to put the palm of the hand on the shifter and push straight forward. The springs guides it perfectly to the next gear. When you hit the stop it feels solid and you KNOW you are fully in gear. I like it.

The motion is firmer but not terrible. It's what you sacrifice to gain a shorter shift throw. The gears are easy to find and you never wonder what gear you are in. Almost like a modern day car (except it's a 915)

I felt the unit is well made and well thought out. The only negative I have is a lack of warning that the shifter shaft is .010 larger. I was told that the stock 915 knob and sleeve and boot would work. I didn't bother to measure it and when installing the ball, it split due to the larger size. A cherry 915 ball is like gold and cost a fortune (if you can find one) so I was upset about that so be careful in that area.

It's an expensive upgrade at $510.00 but adds a more modern feel to an antique design. Not a bad investment.

[McMark]

Thanks for the writeup Paul. Great to hear a real world perspective. (IMG:style_emoticons/default/thumb3d.gif)
Bummer about the shift knob, though. (IMG:style_emoticons/default/sad.gif)

[PRS914-6]

Just another tid-bit. The side to side spring tension is really easy to adjust and a nice feature. JWest includes some nice thick spacer shims to increase the spring tension but I found that adding one shim makes a huge difference in feel.

I used some SAE #8 steel washers available at any hardware store that are about 1/2 the thickness to fine tune the feel. You can get it exactly how you like it. (IMG:style_emoticons/default/driving.gif)

[Chris Pincetich]

Rennshift rocks! (IMG:style_emoticons/default/beerchug.gif)
My clutch tube was totally in the way, bumping it over and mounting the shifter on top of some washers helped. Nice to hear I am not the only one who encountered this. For my 914 I went 33% reduced throw then added an extension so the shift knob is higher than the bottom of the steering wheel. The positioning is awesome and the extension gives me more leverage.

[JWest]

Paul, I'm surprised you had an issue with the knob. Was this the early 915 knob with the clear window or the later one-piece type? Were you trying to slide the knob over the crush sleeve or did you insert the sleeve into the knob first?

[PRS914-6]

Paul, I'm surprised you had an issue with the knob. Was this the early 915 knob with the clear window or the later one-piece type? Were you trying to slide the knob over the crush sleeve or did you insert the sleeve into the knob first?

The way I usually do it is stick the sleeve in the ball and then slide the shifter in and pound it down with the palm of my hand. That way the sleeve is in the thick part of the ball before pressure gets applied. The stock shifter has a nice taper on the end that allows it to get started. The Rennshift doesn't have a taper to speak of and it's slightly larger so it makes it really tough to get started. I didn't want to grind a taper on it in case I opted for an extension.

It's part my fault, when it was going on so tight I should have checked the size. The ball I used is the later solid black unit. It's on but split down the side.

[JWest]

The later knob has a metal sleeve cast in it - I think you put pressure on the lower part of the knob where it is thin and there is only plastic. I've never had an issue with the knob splitting when the crush sleeve is up in the knob.

You are right, there is no chamfer on the top of the stick, and that is for the same reason you state - to be able to blend in a nice extension if desired.