901 tranny question

Maximum John · 12-04-2011, 03:53 AM

Hi, new to Porsche, I have a 1970 with a 2.7 and 901 5 speed that will grind into 2nd if I shift to fast if I ease into it it sounds find but if I have to race a mustang or else I can't push my first gear. I have a west. short shift new bushings??? Any help in that matter would be appreciated

Porchcar guy · Porchcar guy's Garage

A 911 has a very long way to go from shifter to tranny. You might try double clutching and a slight pause between 1 and 2 and a rev up in the middle of the shift. It takes a while to learn this very different vehicle shifting technique but you will learn it or a tranny rebuild will be in your near future.

ratpiper71T · 12-04-2011, 07:08 AM

Others with more experience/ knowledge will chime in soon, but I believe the consensus is you should never push your 901 in first gear. It's cantilevered off the case and unsupported by the main shaft of the trans. Porsche designed the 901 when a rolling start was the beginning of a race. This is my understanding anyway..

Flieger · Flieger's Garage

911s are not meant for drag racing. Go easy on the shifts. Also check the clutch adjustment. A mis-adjusted clutch will result in grinding gears.

Maximum John · 12-04-2011, 10:36 AM

Thanks for the info, as a long time loving the 911 look and thinking as a true sports car I didn't think it would be so difficult to reach 0 to60 in a decent time? I love that car after a few weeks I was able to tweek the mfi to where she runs so sweet so I definitely thought I could adjust the shift linkages or clutch cable but it's ok I truly enjoy this car, just have to learn how to shift properly

dion914-6 · 12-04-2011, 01:34 PM

Sounds like a synchro to me. I have the same issue on my 3rd gear shifts. It hasn't bothered my for 2 years as I just rev match or double clutch, but I know it has a bad synchro.

Flieger · Flieger's Garage

Another standard thing to check is that the bushings in the shift coupler between and behind the seats are intact, along with the bushings in the ball and socket at the bottom of the shifter, and the ring bushing which holds the shift rod.

Maximum John · 12-04-2011, 04:35 PM

Yea did that and it helped, took her for a ride this afternoon and double clutch does help but again it slows your shifting,I'm going to look at my cable adjustment every once in a while reverse and 1st to will grind

DCOP · 12-04-2011, 05:12 PM

Hey Max J. I have a similar set up in my '70. I have a 2.7 with Weber's sport exhaust and hotter cams. My 901 is the original transmission with and has been inspected by my mechanic. He did do some dog teeth work and said the transmission looked good. I did have some shifting issues but found that new coupler bushings and readjusting the shift linkage a couple of times to get it just right made a big difference. I always make sure that I get a clean shift from 1st to 2nd and after that you can pour on the power. The 901 wasn't designed to handle much more power than the 2.2 would give it but I've been running my 2.7/901 for about 5 years without any problems. I also agree that the older Porsche's were not designed for drag racing but they are very quick once you get them off the line. With the proper adjustment and a little finesse you can get very proficient at going through the gears in your 901 without grinding. With all that said, I do check the classifieds now and then for a good 915...

Matt Monson · 12-05-2011, 07:42 AM

901's are no good for 0-60. Stick to 15-75mph with it with a rolling start in 2nd and you'll do better. But it's no stoplight racer...

Maximum John · 12-05-2011, 03:40 PM

I tend to forget it is a 41 year old car that runs realy well for that age and in south florida all we have is stop lights and no twistees but boy is she fun on the highways. Thanks for all the imputs, I'll get on one of my bike if I want to stop light race