Two 901 questions

Jim Sims · 07-26-2006, 08:23 PM

I'm involved with rebuilding my first 901 transmission (I've rebuilt five 915's). A couple of questions have come up.

The first is with the synchronizer brake bands; all nine brake bands originally in the transmission are longer in arc length than what I thought was the correct replacement brake band (911-302-316-08). They are about the the same arc length as an early 915 1st or 2nd gear brake band (915-302-316-01) but have a lesser (tighter) radius. See the below image of the profile tracings. The transmission housing has the characters "HA 24 10 Z" stamped on it. I believe the transmission to be from a 2.0 liter 914. Can anyone explain the brake band difference and provide the correct part number for these longer, tighter radius brake bands?

Second question: The bronze (brass?) speedometer gear projecting from the special shaft bolt has significant play (both lateral wobble about the roll pin axis and some rotational play about the gear axis) at the end where it is secured to the bolt with a roll pin. This doesn't appear normal but the speedometer was working okay before the transmission was removed from the car. Is this "play" normal and if not, is there a repair that can be done other than replacing the speedometer drive gear.

Many thanks for any help you can provide. Jim Sims

nine_one_4 · 07-26-2006, 10:11 PM

You might find your answers here http://home.san.rr.com/pb914/ .

Tobra · Tobra's Garage

that is a great link

Bleyseng · Bleyseng's Garage

Quote:

Originally posted by Jim Sims
I'm involved with rebuilding my first 901 transmission (I've rebuilt five 915's). A couple of questions have come up.

The first is with the synchronizer brake bands; all nine brake bands originally in the transmission are longer in arc length than what I thought was the correct replacement brake band (911-302-316-08). They are about the the same arc length as an early 915 1st or 2nd gear brake band (915-302-316-01) but have a lesser (tighter) radius. See the below image of the profile tracings. The transmission housing has the characters "HA 24 10 Z" stamped on it. I believe the transmission to be from a 2.0 liter 914. Can anyone explain the brake band difference and provide the correct part number for these longer, tighter radius brake bands?

Second question: The bronze (brass?) speedometer gear projecting from the special shaft bolt has significant play (both lateral wobble about the roll pin axis and some rotational play about the gear axis) at the end where it is secured to the bolt with a roll pin. This doesn't appear normal but the speedometer was working okay before the transmission was removed from the car. Is this "play" normal and if not, is there a repair that can be done other than replacing the speedometer drive gear.

Many thanks for any help you can provide. Jim Sims

#2. That play is normal so don't worry about it.
#1. Hmm, I am not sure exactly what you are talking about but I assume you mean the sychro's which I didn't think were similar to the 915's. The 901 out of a 911 or 914 are the same except for the flipped diff and how the shiftrods are setup. I have forgotten exactly what the tranny codes mean but that sounds like a 914 code. If its a side shifter then its for sure a 914 tranny and and 901 parts will fit.

djpateman · 07-27-2006, 11:58 AM

The tranny #'s following the 'HA" are a date code and the Z is definitely wrong there.

Dave at Pelican Parts · Dave at Pelican Parts's Garage

Are you sure the last character was the letter Z? The nomenclature I know of for 914s has a single number there... E.g., "HA O5 08 4". Could it be a "2" or a "1"?

--DD