Shifter and linkage questions (915 trans.)

cowtown · 01-30-2003, 08:16 PM

Hi everyone,
I've been stripping the interior of my new '75 911S and checked out the shift linkage and shifter today. There are a few issues that I need some help with-

1) The shifter has been raised up at some point by shimming it up with some particle board. To offset this lift and keep the shift rod bushing at the correct level, there's a piece of aluminum stock with holes for those two 5mm bolts that hold the bushing's bracket on. Is there ANY reason that this would have been done besides raising the shifter up? I want to take out the shims and return it to stock, unless there is a good reason for this kind of modification? It does not look really well engineered to me

2) There is a piece of metal on the shifter that looks to me like an upside down U-shaped guide, but it's positioned too high to function this way...is this correct, or should it be lower, and slide over the vertical base pieces. What's the purpose of this part?

3) Moving on to the linkage by the rear seats, the pin was only halfway into the bushings. The bushings have basically round holes, with two flat spots opposite each other, but the pin is round and there is a bit of play. Are these the correct bushings, and how much play should there be?

Sorry about the length and amateur nature of these questions. I'm learning a lot with this old car.
Thanks!
Colin

ischmitz · ischmitz's Garage

1) looks like the cheap mans version of a short shift kit.

2) might be that someone did not like the 5th/reverse lockout and modified it or it is a result of 1)

3) those bushings should be tight IMO. You can get replacements from our host.

is

911pcars · 01-30-2003, 09:13 PM

The particle board shift housing spacer and raised shift lever appear to be someone's "poor man's Weltmeister short shift kit." WM uses a cast aluminum piece instead of particle board and a longer add-on piece below the pivot point. Not sure what the PO did to raise the lever that amount.

The U-shaped piece normally engages the vertical tabs when in 5th and reverse gears. The shift lever is spring loaded. While in 5th or Rev., the tab rests on one of the vertical pieces. This relieves spring tension on the transaxle shift mechanism while in those gears.

Not sure what the PO did. He may have redrilled a pivot hole in the lever to change the ratio or added a piece or ?? On a factory stock shift lever, the distance (straight line) from the middle of the shift knob to the pivot hole should be 292 mm. The distance from the center line of the pivot hole to the center of the shift lever ball (bottom end) should be 42mm.

I'd try to compare this with a factory shifter and see what the PO did to the lever. There are plenty of factory stock shift levers floating around from owners upgrading to the factory short shift kit.

A new WM kit is around $80 and the factory SS kit is around $125 in case you decide to go that way.

The shift coupler shaft looks like it's not installed correctly; in fact, it looks like it's a longer shaft. It should be flush on both ends. There is normal fore-aft play betw. the shaft and the bushing but there shouldn't be any perceptible play in any other direction. Also, take a look at the two plastic bushings under the shift housing (below the particle board) as they wear and increase shift slop. A new shift coupler is around $50. A rebuild kit won't include a new (correct) pivot shaft.

I forgot to ask. How does it shift? On the other hand, particle board is a fairly decent electrical insulator.

Sherwood Lee
http://members.rennlist.org/911pcars

cowtown · 01-31-2003, 07:11 AM

Thanks for the good information. It makes sense that one of the 4 POs tried to do a cheapskate short-shift. Sherwood, I'll disassemble the shift mechanism tonight and measure those lengths. Right now, there is soooo much grease in there that I can't see a thing. I've only seen more grease in one place when I did the CVs on my '88

Looks like there was a good amount of backyard-engineering performed on this car, but it's what I was looking for in a project, so it's just another "challenge"

scottb · 01-31-2003, 09:36 AM

If you're going with a short shift kit, spend the extra few bucks and get the factory kit. The pin in the coupler should go through both bushings, and be more-or-less flush with the outside of the bushings on both sides. The fact that it's halfway out could be a good thing if you intend to replace the bushings. Getting the pin out is often a PITA, and if it's halfway out already, my guess is that it will come out all the way very easily. Order a new set of bushings from our host (about $15) and you'll be back in business.

Gunter · Gunter's Garage

Check the two plastic bushings: One is the ball cup at the end of the shift lever and the other is underneath the shift tower and it guides the shift rod in the tunnel. They are cheap to replace. It is odd that the 5th/Reverse lock-out is so high away from the tabs on the shift tower. Even with the home-made spacers, the whole tower, including the shift lever, should have come up. If there is play in the shift coupling, replace the two bushings. Some have oval holes and others are round.

cowtown · 02-02-2003, 07:53 PM

The pin in the coupler was really easy to get out, and the coupler bushings were not a very good fit for the pin. I'll go ahead and get a new set of bushings, and probably a new short shift kit. I'll take your advice and get the factory setup.
Thanks!
Colin

cowtown · 02-03-2003, 06:42 PM

Hi,
I've disassembled the previously described shifter and taken the measurements Sherwood gave me:

Center of pivot hole to center of pivot ball: 58mm. 15mm too long.

Top of shift knob to pivot hole: about 315mm (I estimated this a bit because the knob was off the top when I measured) 25mm too long.

Any idea what's going on here? Is this shift lever incorrect for the car? Is this mystery better left unsolved (meaning should I just call up Pelican and get the factory kit tomorrow)?

Thanks!
Colin

911pcars · 02-03-2003, 09:01 PM

Colin,
The important dimension is the pivot hole-to-pivot ball distance. At 58mm, this is, as you report, 15mm longer than stock. BTW, this distance is 5mm longer than the Weltmeister shifter (53mm) and 4mm longer than the factory short shifter (54mm).

The PO has indeed tried to create their own version or at least replicate the WM design. I'm guessing the particle board spacer under the shift housing is 5/8" thick (approx. 15.8mm) to space the housing higher to compensate for the 15mm longer lever past the pivot pin hole.

The upper end of your current shift lever is 23mm longer than a stock shift lever (292mm). That dimension really negates any reduced shift travel created by the aforementioned longer lower end. You want a shorter upper end, not longer. With your current setup, you won't feel any travel reduction between gears over a stock unit.

Enough of the details. I suggest retrofitting either a factory setup or a factory short shift kit to get the "correct" parts in there. If you put a wanted adv. in the classifieds, you should come up with a bunch of hits for factory shift levers.

BTW, I'm taking this info from a very thorough Pano article reprinted in Vol. 8 of PCA's UpFixin' series (Short Shifters Analyzed by Dickerson and Gagnon).

Sherwood Lee
http://members.rennlist.org/911pcars

cowtown · 02-04-2003, 06:57 AM

Sherwood, thanks so much for taking the time to help me out. It did not make sense to me that both dimensions were too long if the purpose was shorter shifts. You're exactly right that the wood is 15mm thick.

I'm coming from a G50 car to this one, so I'm going to go ahead and shell out for the correct factory shortshift kit. I'll also renew all the shift and linkage bushings while I'm in there. I think it's a case of "do it all now or do it all later."

Thanks again!
Colin