Re: 904 trans with a 2.74 first gear ?
[Re: dOc !]
#2738964
02/02/20 11:27 AM
02/02/20 11:27 AM
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Joined: Mar 2011
Posts: 3,093 Michigan
A727Tflite
master
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master
Joined: Mar 2011
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Michigan
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The trans gear ratios and trans designations are independent of each other.
The use of the low gearset came about to allow use of a numerically lower rear axle ratio for fuel economy - used in either a 904/998/999.
The 904/998/999 designation came from relative torque capacity - the number of clutch discs and band widths used.
My recollection is the low gearset became available in 1980.
Last edited by Transman; 02/02/20 11:28 AM.
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Re: 904 trans with a 2.74 first gear ?
[Re: A727Tflite]
#2739069
02/02/20 03:44 PM
02/02/20 03:44 PM
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Joined: Jan 2003
Posts: 3,122 Auburn WA
Dave_J
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Auburn WA
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Just about any Mopar that had 2.45:1 and 2.20:1 ring and pinion had the A999. My J body Mirada did. The 1995 GTE Phone repair Dodge B van with the 3.9 we scrapped did also.
Retired, US ARMY 1973-1994 ASE mechanic, Electrical 1994-1997 Retired GTE/VERIZON/FRONTIER 1997-2015
Posting cheap tech help (CRAP) here since Nov 97, 1000's of posts, some may be good.
03 Suzuki Burgman 650(Burger King) Scooter 65 Formula S Cuda 78 Little Red Express Truck 98 Buick Regal (wifes car)
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Re: 904 trans with a 2.74 first gear ?
[Re: dOc !]
#2739098
02/02/20 05:07 PM
02/02/20 05:07 PM
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Joined: Jan 2003
Posts: 25,967 Rio Linda, CA
John_Kunkel
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Rio Linda, CA
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First A999 was '74, first low gear set was '80, by '82 all of the 904 family had the low gear set.
The INTERNET, the MISinformation superhighway
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Re: 904 trans with a 2.74 first gear ?
[Re: Jjs72D]
#2739207
02/02/20 11:03 PM
02/02/20 11:03 PM
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Joined: Dec 2005
Posts: 11,692 Fulton County, PA
CMcAllister
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Mr. Helpful
Joined: Dec 2005
Posts: 11,692
Fulton County, PA
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As I understand it, all 8 cylinder. lock up trans (late 70s, 80s F bodies, big cars) have the 2.74. Correct?
If the results don't match the theory, change the theory.
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Re: 904 trans with a 2.74 first gear ?
[Re: Jjs72D]
#2739372
02/03/20 04:06 PM
02/03/20 04:06 PM
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Joined: Jan 2003
Posts: 25,967 Rio Linda, CA
John_Kunkel
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Rio Linda, CA
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How do you read the stamping on the transmission cases to determine the year of manufacture? The last 4 digits of the numbers stamped on the pan rail are the build date based on a 10,000 day calendar. Post the number to decode. None of the 904 family had the low gear set in the seventies.
The INTERNET, the MISinformation superhighway
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Re: 904 trans with a 2.74 first gear ?
[Re: CMcAllister]
#2739853
02/05/20 08:00 AM
02/05/20 08:00 AM
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Joined: Jan 2003
Posts: 2,059 MD
RTSE4ME
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MD
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As I understand it, all 8 cylinder. lock up trans (late 70s, 80s F bodies, big cars) have the 2.74. Correct? I have two 8 cylinder. lock up trans that don't have low gear sets or 5 disc drums.. There are a lot of variations so you don't really know what you have until you tear it down.
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Re: 904 trans with a 2.74 first gear ?
[Re: RTSE4ME]
#2740315
02/06/20 01:06 PM
02/06/20 01:06 PM
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Joined: Jan 2003
Posts: 25,967 Rio Linda, CA
John_Kunkel
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Rio Linda, CA
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There are a lot of variations so you don't really know what you have until you tear it down. That's true of any aged trans, never know what's been done at overhaul but the part number stamped in the pan rail tells how it left the factory. What inside parts are correct can be determined by perusing the factory parts catalog.
The INTERNET, the MISinformation superhighway
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Re: 904 trans with a 2.74 first gear ?
[Re: dOc !]
#2740901
02/08/20 09:56 AM
02/08/20 09:56 AM
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Joined: Jan 2003
Posts: 2,059 MD
RTSE4ME
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top fuel
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MD
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What specific vehicles are those ? They were early 80s cars if I remember correctly. I looked up the numbers. I scrapped one of the cases because it was cracked and the other is in my race car. I tried to get the numbers off it but the shifter bracket is in the way. John is correct one of the tranny's was gone through but the one I ended using looked untouched but who knows. When I bought all my parts from CRT he told me about all the variations he has seen.
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Re: 904 trans with a 2.74 first gear ?
[Re: JDMopar]
#2743633
02/16/20 04:06 PM
02/16/20 04:06 PM
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Joined: Dec 2005
Posts: 11,692 Fulton County, PA
CMcAllister
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Mr. Helpful
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Fulton County, PA
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Looks like 84-85 904 in a big car (Mirada, Cordoba, 5th Ave). 318.
Best way to tell is pull it apart and look.
Last edited by CMcAllister; 02/16/20 04:07 PM.
If the results don't match the theory, change the theory.
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