Short shifter kit
 

I recently purchased a 1986 911 Carrera w/ 88K miles and am thrilled with the car. I

Previous owner had local Porsche dealer install short-shift kit last February. Seven months later in September 2012, and after driving car for about two thousand miles, previous owner brings car back to dealer complaining of difficulty in going from first gear to second. Dealer "installed" synthetic transmission fluid and advised that gear oil will "need time to get through gears & syncros". That was about 500 miles ago.

During Pre-purchase inspection in December 2012 engaging second gear was noted as a problem area. My mechanic (a Porsche specialist) indicated this might be remedied by replacing the synchros (I'm not a mechanic, so apologies if I did not use term correctly). He also suggested that removing the short shift kit might also have a favorable impact on the difficulty of going from first to second gear. Then he stated that he'd remove the short shift kit anyway, as he believes these kits put unneeded stress on the transmission.

I’ve put about 1200 miles on the car since purchasing it and to some degree have gotten used to the extra bit of muscle required to get the car into second gear. Sometimes it’s not bad at all. Other times yes – a good bit of oomph is required to lock her into second. My mechanic assures that other than the small amount of unneeded stress added by the short shift kit, I’m not doing any damage to the transmission by driving it in its current condition.

Currently I’m thinking that at the next oil change, still about 3000 miles off, I’ll ask mechanic to take out short shift kit – then see how she shifts. However I’d like to get some opinions from the Porsche community. What would you do? Does the short shift kit indeed place unneeded stress on tranny? Might first to second gear shift easier without the kit? Should I go ahead now and have the mechanic replace the synchos?

A couple of items:

• The 1986 came from the factory with a shorter shift throw than the prior 915-transmission cars (except the ones with the factory short shift kit). Do you have the stock shifter? I have an '86 (until recently had 2) and I like the stock shifter just fine.
• I doubt the shorter shift is making a huge difference in an '86.
• Are there times when it easily goes into 2nd or is is always just as hard? With bad synchros, it should go in easily some of the time.
• You should be double-clutching downshifting from 3rd to 2nd if you are having problems
• Introduce yourself here. We generally use 1st names and put our cars in our signatures. Photos of your car would be good, too.

Welcome to the wonderful world of the high mileage 915 transmission. Balky shifts are normal, and yes can be aggravated by a short shift kit IF you try to shift this thing like a brand new Honda Civic.

The 915 is a slow shifting transmission. A brief pause in neutral between gears on upshifting helps a lot. Short shift kits are great because the factory shifter has you putting your arm in the back seat. You just have to take it slow and you'll be fine. Short shifters don't change any internal parts of the transmission, so there's no more stress if you shift correctly than with the regular shifter. The short shifter makes it easier to shift faster, but as long as you're conscious of this, you'll be fine.

New fluid can help a balky shift. Never heard of "taking a while to work into the gears", though. Every time I change trans oil I notice the difference almost immediately. Like a lot of 915 guys I use Swepco 201. I've heard that synth oil doesn't work great with the older style synchros in the 915, but that was probably something someone heard from this guy whose college roommate's brother worked on a Porsche once.

Make sure your clutch is in correct adjustment. These are cable actuated clutches and if out of adjustment can cause the engine/trans to not fully separate, messing with your shifting as well.

Finally, never shift into 1st unless your are stopped or almost stopped. I've driven a few 915s with good 1st gear synchros, but they are few and far between.

maybe an adjustment to the shifter in the trans tunnel at the rear seat is necessary? Might be a good question for your mechanic.

Good point. Ordering a set of Charlie's brass shift coupler bushings would probably help, too.

Mahonj,

First, I would get rid of the synthetic gearbox fluid; the 915's like the mineral based gear oils. Like Jazzbass, I I have used Swepco 201 80w90 gear oil in my 915 gearbox and it works great.

I agree with the comments that your shift coupler probably needs needs to be adjusted. It is located under a rectangular metal cover just behind the front seats on top of the center tunnel "hump".

It would also be worth the few extra bucks to replace the shift coupler bushings with
brass bushings. I replaced mine a few yeas ago and my shifting improved greatly. I got my brass bushings from Pelican Parts.

Good luck.

Who got them from Charlie. :lol:

I've had one of the original sets in my car for almost 10 yrs. Great upgrade.

Many thanks.
 

Thank you all so much! This is the first time I've ever participated in any kind of "on-line" discussion - or "blog". And I'm very grateful for your inputs. I will be following your advice.
Jim

Me, even got another set from the current run for the race car.

+1 on Charlie's brass bushings. The shifting is more direct on my 86 with the factory short shift option. Another upgrade that surprised me was tranny and motor mounts. That made the clutch and shifter feel much more solid.

I will offer a counterpoint on the gear oil. I put Amsoil in mine because a buddy is a rep and I have been plenty happy. Occasionally I get a grind down shifting to 2nd at the track after 5 seasons, but not often. As for 1 to 2, I go slow and blip the throttle a couple times to maintain revs while the gear selector eases into place.

Another great project is bronze bushings for your peddles.