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ripley

Active member
Joined
Jun 25, 2015
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Location
Conneaut,Ohio
My Car
1971 Mach 1 Mustang
trying to find out how to read the numbers on the side of auto transmisson, RF 07UP 7006 AA or RF D7UP 7006 AA

 
no tag on it its in a 1971 mach 1 i know its a c6 just trying to see if its the orginal one. Thank

 
Look on the top of the trans, if you can. There should be a partial VIN. if it matches your VIN it is original. Chuck

 
Thats Funny that you would answer me the car came from Tennessee



Look on the top of the trans, if you can. There should be a partial VIN. if it matches your VIN it is original. Chuck
I will look tonight and see if i can see it

Thank you

 
Last edited by a moderator:
there should be a tag on the bottom of the servo cover, usually that is the first tag that goes missing.

next on the top of the C6 below the bell housing is a flat area that should have a partial vin stamp.

if it is from a mustang 71-73 then the first should be a 1,2 or 3, followed by an F the next digits will be the unit number

if the trans came from another ford then the first digit and letter will be different.

An H code had an FMX trans. Q or R or M would of had a C-6

if you are trying to see if the trans is original to a 71, then you want to see the 1F followed by the cars partial vin on the top stamped area.

from there you can work back the original tag on the servo cover.

would start with PGA or PGB

AH, AU would of been a 4 barrel

you want to correlate it with the 4th Vin Letter as well for the engine.

you can also look at the letter on the servo Cover above where the tag is suppose to be.

From Softest to Most firm

CODE ON COVER, APPLY DIA, RELEASE DIA, SEAL TYPE

N 1.93 2.92 Molded piston

S 2.00 2.86 Molded piston

G 2.04 3.02 O-rings

J 2.07 2.69 O-rings

L 2.07 2.98 Molded piston

D 2.08 2.98 O-rings

P 2.10 2.86 Molded Piston

H 2.34 3.02 O-rings

R 2.48 3.50 O-rings

the closer you get to R the higher the performance of the Transmission.

back then you would of seen a S or J on the cover the big block Cobra jets got R servos

 
motorarts is correct

D7 is 1977 the U is Van

the engine was most likely a 351W same bolt pattern as the 351C small block.

Truth is that trans is better then 71 original.

you would have to crack it open to look at the internals but i would bet the Direct and forward clutch packs are 4 fiber.

and the reverse clutch might be 5-7 clutches.

the original 71 c-6 would of been 3 forward, 3 direct and 4 reverse clutches making it much weaker then the 1977 version for a van that was beefed up internally.

confirm with the VIN on the top of the C-6 use a wire brush to get the crust off.

sometimes C-6s from trucks or vans have 4 gear planetary gear sets these are much stronger then 3 gear versions for cars.

 
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