[Eds_Automotive727]

Hello, all. I am a mechanic in St Pete, Florida, and I have a customer with a 1997 Vette, having some automatic transmission problems, 3rd gear is going out and he wants me to replace the unit. He has a 1997 with a "7YDD" designation, and he has a source on a 1999 unit that has a "9YDD" designation, and the only thing I can find on them difference (other than the code) is that the earlier one is a VIN P and the new one would be from a VIN G. Supposedly they're the same from 1997-2004, but I would hate to get the job halfway done and find out it's not quite right. Any help would be greatly appreciated. Thanks.

 

[Maniacmechanic1]

They are all 4L60E A4 auto transmissions except for the C5 2005.
2005 It was an improved 4L65E.

 

[Maniacmechanic1]

The Sungear shell in all 4L60E production are prone to failure.
3-4 clutch packs fail.
2-4 bands fail.

Custom built ground up best.
Do it yourself and you know what you have and its done right.

 

[Maniacmechanic1]

The Valvebody is all aluminum.
They wear out and causing many issues.
Rebuild or replace it best.

Not an issue in old 700R4 and TH400.
All cast iron valve body used.

 

[Maniacmechanic1]

When you go to rebuild keep in mind all C4 Corvettes had a special Valvebody and steel seperator steel.plate.
C5 has a special Corvette only separator plate.

 

[Marc9118]

Hello, all. I am a mechanic in St Pete, Florida, and I have a customer with a 1997 Vette, having some automatic transmission problems, 3rd gear is going out and he wants me to replace the unit. He has a 1997 with a "7YDD" designation, and he has a source on a 1999 unit that has a "9YDD" designation, and the only thing I can find on them difference (other than the code) is that the earlier one is a VIN P and the new one would be from a VIN G. Supposedly they're the same from 1997-2004, but I would hate to get the job halfway done and find out it's not quite right. Any help would be greatly appreciated. Thanks.

Hi m'y friend im in the exact same position than you with a 1997 and i look to instal a 2000 ! So finaly everything is fine no Matters the tag ? Thank i apreciate