time to rebuild tranny-questions...

[bob tilton]

the serial number stamped on the 5 spd tranny is 902/1 (227333) mated to a non-stock 2.2 (901.101.102.2R). i will be ordering a new clutch package but have a few dumb questions.

i don't know if the tranny is original to the car. i have heard they are all very interchangeable. in skimming through the parts catalogs - will i be requiring the 65-69 clutch package or the 70-71 clutch package? a 215mm flywheel or a 225 mm flywheel?

i understand there is a push-pull difference between 901s. i don't know if the previous owner intalled a later 901 tranny to the 2.2 as opposed to the 2.0.

thanks in advance,
bob
'68L

[john walker's workshop]

a 902/01 is a 4 speed. so if yours is a 5 speed, someone used that case, and who knows which ratios. to make a 5 speed. 70-71 901s used the pull clutch, so yours is an earlier push type.

[Paul W]

Hi guys.

Normally I wouldn’t way into this sort of discussion, but thought I would in this case to perhaps offer some clarification.

John is of course right in advising that the 902/01 was a four speed, but according to the manual the 902/1 transmission was a 5-speed box. For a quick reference page SR3 of the transmission section of the factory manual has a Transmission Diagram, noting various ratios, including 5th. In addition I also have this (902/1)5-speed box in my car.

John, please don’t think me presumptuous in offering this information.

Good luck Bob.

Cheers

[Early_S_Man]

The 902/1, as opposed to the 902/01 ... was a 5-speed equipped with AFMSX gearing, and may have been the original transaxle in your car, because it was the standard transaxle installed for the 1968 911L USA model.

[bob tilton]

thank you gentlemen. can i pick your brains further?

just to confirm - i will to order the 65-69 clutch package and if needed the 215mm flywheel?

what is AFMSX?

any suggestions in re: to the project such as lighten flywheel, alum flywheel, shorter gears, taller 5th? i will most likely have the existing tranny prof rebuilt as opposed to the vertex exchange program. i have contacted vertex and their price is $1050 plus $150 round trip shipping. great price however - i don't know what's inside their gearbox and i prefer to support my local business. i have budgeted $2500 for the project which will hopefully include rebuilt tranny/new clutch/labor. does that figure seem accurate?

just to give some background - first/reverse gear growls like a bear and the car "chatters" from stops. can i expect to replace the flywheel instead of resurfacing the existing one?

again, thank you.

bob

[Early_S_Man]

Bob,

The factory used letter codes for gears since the early 1950's, and the codes were unique to each transaxle design, i.e., 901/904 codes don't match 915 codes or 356 codes!

A, F, M, S, X represents:

1st gear - 'A' = 11/34 = 3.091:1

2nd gear - 'F' = 18/34 = 1.889:1

3rd gear - 'M' = 22/29 = 1.318:1

4th gear - 'S' = 25/26 = 1.04:1

5th gear - 'X' = 28/24 = 0.857:1

Whenever I hear or experience 'chattering' of the clutch on takeoff ... I usually call it a 'judder,' and it has always been due to oil on the clutch disk. No, I don't see a problem getting the flywheel refaced, as long as they do the proper job and machine the clutch disk 'working' surface and the pressure plate mounting surface equal amounts!

[john walker's workshop]

oops, sorry, one too many 0s.

[bob tilton]

thanks warren for the explanation. i've been doing some research on other topics and of course your helpful replies can be found throughtout. it is much appreciated.

johnny - can i walk away from this project under $2500? i have more projects for the car planned for this year.

thanks,
bob