Please decipher transmission casting numbers

Identification information of frames and transmissions
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docmel
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Please decipher transmission casting numbers

#1

Post by docmel »

Its a 4 speed, ratchet top. I got it from a guy on Craigslist, who was selling a bunch of Pan, early Shovel stuff.

On the kicker cover side, top of case, I see the numbers: N18.
Bottom of case:
On a raised boss: 5-77
Stamped: 34703 77
1

Any help is appreciated


34703 77
RUBONE
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Re: Please decipher transmission casting numbers

#2

Post by RUBONE »

Sounds like you have a Mid '77 version type 4 speed, after the change to a caged needle roller on the mainshaft and caged needle countershaft bearings as used until the advent of the rotary top. The 5-77 could be May 77 which would make it a late '77 or early '78 model year box. What is the rest of the alpha numeric number near the detent plunger, the N18 should have more digits? Speeding Big Twin should be able to tell you for sure.
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Re: Please decipher transmission casting numbers

#3

Post by Speeding Big Twin »

As Robbie mentioned, it’s a 77 type trans. The earliest use of casting number 34703 was for later-1964 models (34703 64), followed by 34703 65 which debuted for 1965 models and which seems to have then continued through 1976 because the next one I’m aware of is yours: 34703 77.
Your case may have been cast in May 77 as indicated by date code 5-77. (But some 34703 77 cases don’t have a date code.)

I don’t know what N18 indicates on top of the case. Other markings I’ve seen there on 34703 77 cases are N21 and N28 but some have nothing.

I don’t know what the lone 1 underneath indicates and some of those cases have a lone 2. My best guess is that they may be an inspector mark. The two previous cases (34703 65 and 34703 64) are known to have had 1 or 2 and the case before that (121-35) can have 1, 2, 1E or 2E.

Stamped on the front of your trans just below the lid and nearer the R-H end there may be an additional original component identifying number consisting of one letter followed by either three or four numeric characters. This is also referred to as a security code or an anti-theft number. In your instance, the letter may be W, X, Y or Z but can you confirm which letter you have please. (We don’t need to know the three or four numbers.)

The ratchet lid could be anywhere from late-51 to mid-79. If it has provision for a neutral switch it will be somewhere from 59 to mid-79. If the lid is secured by countersunk socket-heads then they may indicate a 65-later lid.

Is the shifter cover (#34551-52) secured by six sockethead screws? If so then they too may indicate a 65-later ratchet assembly.

What type of shifter shaft lever has it got? Most have the style that first appeared for some late-51s (#34447-52) but there was at least one other (#34447-74) and it was used for 1974--mid-79 FX-series machines.

Re the kicker cover, we may be able to help ID that too if you post a photo.
Eric
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