901 tranny

[blanchmann]

hi.
I'm a new and proud owner of a 71' 911t. After driving the car for more than a week I can say that I'm not a real big fan of the 901 transmission. It seems to grind into 2nd gear unless it is really gently feathered in. Also, the gear box feels "large". Moving between gears seems to be a long way. I'm wondering about these short shift kits. Do they make them for the 901? If so, will this kit make the gearbox "tighter"? Does anyone else have similar experiences with their early cars? Thanks in advance.
-jb

[Jandrews]

With a '71, your trans should technically be a type 911/01. Same shift pattern as a 901, but technically a different gearbox.

These trannys do tend to feel like a stick in a bucket of mud, but you will get used to it. The grinding is no fault of the 901 per se, rather probably a case of worn synchro's, something any manual transmission can suffer from.

I have a '71 911/01 tranny in my car paired up with my 2.7RS MFI motor and 7:31 R&P, and I love it! I wouldn't trade it for a 915 under any circumstances. My gears are a bit high A,F,N,V,Zd, but it shifts well and is great at the track moving through 2nd and 3rd gears. I have a short shifter for mine, but I have never installed it. It is by no means comparable to a modern japanese or european shifter, but it has its own charm and it can be very effective.

Best,

JA

[SandyI]

The 901 has very long throws. In fact, the distance between 1st to 2nd, and 3rd to 4th is HUGE. But if your 901 is running properly, you shouldn't be grinding from 1st into 2nd. Unless you're attempting to rush the shift like a modern tranny. Have you checked the bushings? They're key to smooth shifting. Adding a short shift kit technically shortens the throws but increases the friction so the shifts aren't any faster because they take more effort. I know because I run my 911E with a stock 901 and just recently purchaesd a 914/6 3.2 with a short shift kit. The short shift kit is being removed. With practice, you'll figure out the fastest shift possible and find the 901 to be a perfect match to your stock T engine. I love my 901 in my 911E. I've put over 25,000 daily driving miles on my car in about four years including more than a dozen POC track days at Streets of Willow. I wouldn't trade my stock 901 for a 915 or a G-50.

[Grady Clay]

jb,

Welcome to the Forum.

The long reach of the shifting is normal and disable. You will eventually find it great and everything will fall to hand.

To get you started in the right direction, the ’65-69 transmissions are Type 901. the ’70-’71 are Type 911, the ’72-’86 are 915 and the ’87-> are various G50 (Getrib 950 and later G64 and other variants). In there (’75-‘87) are the 930 transmissions for the Turbo. This is a very simplistic description and there are many variations.


Your ’71 Type 911 is one of the best Porsche transmissions for light weight and suitability for displacements 2.8 liters and less. Take good care of it.

One issue is the “Simplified differential” that should have a contemporary update. A through Pelican search will educate you there.

A Type 911 transmission is very easy to rebuild at home. You can easily repair worn synchronizers. The Type 911 will never be “tight” and it actually works best “lose”, you just need to learn to drive (operate) it properly. It will never, ever be like a later (996, 997) transmission.


OK, what to do?

The Pelican archives have a lot about this. Search on my name and key-words like “Type+911, transmission, pull clutch” and more. Learning the Pelican Search function is critical to accessing this incredible resource.

Something you can do for me is to post the transmission S/N and Type number. Are they on the bottom rib or on a rectangular boss under the differential? Has your “Simplified differential” been updated?

Best,
Grady

[FrayAdjacent911]

Definitely check your shifter bushings. My '70 when I got it, they were completely shot. New bushings definitely helped. The throw is still a bit long. There is also some 'mojo' to getting the coupler on the shifter rod from the transmission in just the right place. I need to tweak mine. Actually, I moved the engine and tranny to my '69 Targa. Works but still a long throw for the gears. That's just the way the 911/01 is.

I'm not sure about a short shifter either. If one worked well, and wasn't too costly, I would consider trying one.

[FrayAdjacent911]

Oh, I forgot to add, you need to post pictures of your car, or we'll ban you.

[blanchmann]

Thanks for all the great replies. The only thing really frustrating me now is.... I just had all new bushings put in. (Precision Motion in Riverside) Then, I took it to my mechanic here in Venice, to do a once over on the car, and he said he made a mild adjustment to the gear that should help. Well it hasn't..is it just me? I've been driving all sorts of manual transmissions my whole life. I can quite easily shift from 1st to 2nd without grinding but, it has to be very slow and precise. Any fast/high rpm movement when trying to accelerate will grind as it pops into place. Thanks.
-jb

oh yeah, the pic (prior to resto)

[randywebb]

I like the search button at the bottom RH side of the page. I'm one of the people who got rid of my newer (915) trans. to change to the older 911 like you have.

Find out if the guy changed all 3 plastic bushings... look at the parts list on the invoice to start with.

also do you have new trans. fluid in there? Swepco is one of, or the best.

You might get an experienced 911 driver to drive your car with you in it (your mechanic in Venice for example). Also, let him watch you drive & shift.

IF it isn't just that you are conditioned to the trans. then it is possible that your synchros are bad...

[blanchmann]

thanks again. If the syncros were bad, wouldn't I be having problems with all the gears? This is strictly, from 1st into 2nd. All the rest shift smmothly at any Rpm. Also, If I shift slowly its smooth as can be.

[randywebb]

no - each gear has its own synchro

BUT...
"Also, If I shift slowly its smooth as can be."

- you are shifting too fast - do it slow - that's the problem

[gulf908]

jb,

I have gone through this excercise about 18 months ago with my 2.2S.
BEFORE you go installing a short shift,make sure the basics are all 100%.
From front to back -
- have you done the pedal box renovation ?
- check the mechanism under the gear lever for wear and proper lube
- change the rubber coupling at the rear firewall
- change the plastic trunnion to the metal version(Wayne - do you have these ?)
- is the clutch correctly adjusted ?
- is there enough clean correct oil in the trans ?

Having said that,the 901/911 trans is now 35 years old and was not even on a par with the best shifters of its day - the small Fords from the UK - you can't expect it to shift like a modern day car.
But I would never have a 915 again (had 2 for 15 years) - not even on a 2.7 RS !

Cheers,
Dennis.

[limble]

Originally posted by blanchmann
I took it to my mechanic here in Venice,

If you mean Ottos say hello for me. If not look him up. Great guy.

[avalad2]

jb,

I understand your frustration, my 70T has similar issues. After replacing the shifter bushings there is much less play in shifting, but I still have the grinding when going to 2nd. I think it's a bad syncro. You have to open up the trans. to fix that. In the meantime try double clutching when going to 2nd. That's what I do and no grinding. It's annoying, but you won't damage the syncro and dog teeth even more by grinding.

[SandyI]

Originally posted by limble
If you mean Ottos say hello for me. If not look him up. Great guy.

I'll second that. He's done all the work on my cars. I doubt there's a mechanic in So Cal with more experience on early 911's than Otto.

[rw7810]

I just did a clutch ballpin replacement. Common thing to wear out on this model. Also rebiult the 1st gear syncro. Used a coorosion blocker, kinda like the cosmoline, to protect it. PS: I put a short shifter in it 12 years ago and love it.