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#1
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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? |
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#2
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A couple of items:
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Peter (not "Pete") K. 2026 Lucid Gravity Grand Touring (EV Tow Vehicle) 1997 Spec Boxster #671 2016 Cayman S 2016 Toyota Highlander--wife's DD 2017 VW GTI SE (DD) Gone and missed: 2003 Miata ("SM") race car 1992 Miata ("SSM") race car 2009 911 C2S Coupe 2004 Toyota Prius - sold to son's girlfriend 2006 Dodge Durango 2003 Acura MDX 86 Black 911 Coupe race car 86 Gold 911 Targa 82 WineRedMetallic 911 Targa |
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#3
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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.
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Chris M 1985 911 Carrera with a couple cosmetic only mods 2006 E90 330i 1999 E46 328i |
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#4
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maybe an adjustment to the shifter in the trans tunnel at the rear seat is necessary? Might be a good question for your mechanic.
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Patrick '86 Carrera EStock #22 "Driving a race car...it's like lifting weights in a g-accelerator with a heater on full blast pedaling a bicycle and solving a rubik's cube or something at the same time." |
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#5
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Quote:
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Chris M 1985 911 Carrera with a couple cosmetic only mods 2006 E90 330i 1999 E46 328i |
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#6
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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.
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Regards, Bruce '12 Carrera C2S |
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#7
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Who got them from Charlie.
I've had one of the original sets in my car for almost 10 yrs. Great upgrade.
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Chris M 1985 911 Carrera with a couple cosmetic only mods 2006 E90 330i 1999 E46 328i |
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#8
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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 |
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#9
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Me, even got another set from the current run for the race car.
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David I hope to arrive to my death, late, in love, and a little drunk! Just because I don't care doesn't mean I don't understand... Homer Simpson "That's what's keeping me out of F1.... Too much mental maturity...." N0tt0n Some cause happiness wherever they go; others whenever they go. CHAOS, PANIC, AND DISORDER my work here is done... Live without pretending, Love without depending, Listen without defending, Speak without offending Last edited by Trak Ratt; 02-14-2013 at 08:50 PM. |
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#10
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+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.
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Bob 04 GT3 86 Carrera 97 318ti "Guys, I'm coming in, I have too much grip." |
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