1992 C4 - Which Auto Tranny?
Thread Starter
Racer
Joined: Dec 2013
Posts: 419
Likes: 5
From: Bel Air Maryland
1992 C4 - Which Auto Tranny?
There seems to be a lot of conflicting information on the Internet, even among folks who hold themselves out as being "experts" on Corvettes. Specifically, I haven't been able to definitely conclude whether the automatic transmission in my 92 Vette is a 700R4 or 4L60. For every article I read saying that the 4L60 was not introduced until 1993, I read another saying that GM starting using it in Corvettes beginning in 1992. So, which one should it be and how can I figure out which one I have in my car?
Team Owner
Joined: Sep 2003
Posts: 25,348
Likes: 2,728
In the '90 FSM it's referred to as 700R4/4L60, in '91 it's only referred to as 4L60 and in the '92 FSM only as a 4L60.
I'd guess you would refer to it as a 4L60 and your concern needs to be that in '92 the ASR feature was added to the Corvette and the "on the car" adjustments are different and need to be followed. That's your primary concern.
If your concern is that the transmission is original to the car then a VIN derivative is stamped on the transmission and there would also be a data plate attached to the transmission with the ID. The transmission ID's for a '92 would depend on the axle ratio also. I'd expect one of these 2YCM for a 2.59 (GM1) rear axle, 2YDM for a 2.73 (GU2) or 3.07 (G44). I believe an AYCM or AYDM would be considered a GM SERTA replacement.
Both the 700R4 and the 4L60 carried the same RPO on the SPID label you'll find in your console. That RPO will be MD8.
I'd guess you would refer to it as a 4L60 and your concern needs to be that in '92 the ASR feature was added to the Corvette and the "on the car" adjustments are different and need to be followed. That's your primary concern.
If your concern is that the transmission is original to the car then a VIN derivative is stamped on the transmission and there would also be a data plate attached to the transmission with the ID. The transmission ID's for a '92 would depend on the axle ratio also. I'd expect one of these 2YCM for a 2.59 (GM1) rear axle, 2YDM for a 2.73 (GU2) or 3.07 (G44). I believe an AYCM or AYDM would be considered a GM SERTA replacement.
Both the 700R4 and the 4L60 carried the same RPO on the SPID label you'll find in your console. That RPO will be MD8.
Last edited by WVZR-1; Feb 6, 2014 at 09:22 PM.
Race Director
Joined: Apr 2003
Posts: 17,697
Likes: 1,666
From: moraga ca
In the '90 FSM it's referred to as 700R4/4L60, in '91 it's only referred to as 4L60 and in the '92 FSM only as a 4L60.
I'd guess you would refer to it as a 4L60 and your concern needs to be that in '92 the ASR feature was added to the Corvette and the "on the car" adjustments are different and need to be followed. That's your primary concern.
If your concern is that the transmission is original to the car then a VIN derivative is stamped on the transmission and there would also be a data plate attached to the transmission with the ID. The transmission ID's for a '92 would depend on the axle ratio also. I'd expect one of these 2YCM for a 2.59 (GM1) rear axle, 2YDM for a 2.73 (GU2) or 3.07 (G44). I believe an AYCM or AYDM would be considered a GM SERTA replacement.
Both the 700R4 and the 4L60 carried the same RPO on the SPID label you'll find in your console. That RPO will be MD8.
I'd guess you would refer to it as a 4L60 and your concern needs to be that in '92 the ASR feature was added to the Corvette and the "on the car" adjustments are different and need to be followed. That's your primary concern.
If your concern is that the transmission is original to the car then a VIN derivative is stamped on the transmission and there would also be a data plate attached to the transmission with the ID. The transmission ID's for a '92 would depend on the axle ratio also. I'd expect one of these 2YCM for a 2.59 (GM1) rear axle, 2YDM for a 2.73 (GU2) or 3.07 (G44). I believe an AYCM or AYDM would be considered a GM SERTA replacement.
Both the 700R4 and the 4L60 carried the same RPO on the SPID label you'll find in your console. That RPO will be MD8.
Intermediate
Joined: Jun 2017
Posts: 38
Likes: 8
From: The Plains oh
Tranny education
In the '90 FSM it's referred to as 700R4/4L60, in '91 it's only referred to as 4L60 and in the '92 FSM only as a 4L60.
I'd guess you would refer to it as a 4L60 and your concern needs to be that in '92 the ASR feature was added to the Corvette and the "on the car" adjustments are different and need to be followed. That's your primary concern.
If your concern is that the transmission is original to the car then a VIN derivative is stamped on the transmission and there would also be a data plate attached to the transmission with the ID. The transmission ID's for a '92 would depend on the axle ratio also. I'd expect one of these 2YCM for a 2.59 (GM1) rear axle, 2YDM for a 2.73 (GU2) or 3.07 (G44). I believe an AYCM or AYDM would be considered a GM SERTA replacement.
Both the 700R4 and the 4L60 carried the same RPO on the SPID label you'll find in your console. That RPO will be MD8.
I'd guess you would refer to it as a 4L60 and your concern needs to be that in '92 the ASR feature was added to the Corvette and the "on the car" adjustments are different and need to be followed. That's your primary concern.
If your concern is that the transmission is original to the car then a VIN derivative is stamped on the transmission and there would also be a data plate attached to the transmission with the ID. The transmission ID's for a '92 would depend on the axle ratio also. I'd expect one of these 2YCM for a 2.59 (GM1) rear axle, 2YDM for a 2.73 (GU2) or 3.07 (G44). I believe an AYCM or AYDM would be considered a GM SERTA replacement.
Both the 700R4 and the 4L60 carried the same RPO on the SPID label you'll find in your console. That RPO will be MD8.
Team Owner
Joined: Sep 2003
Posts: 25,348
Likes: 2,728
I would like to put in a stronger tranny in my 92. From your post I am gathering that the ASR is part of the transmission. I am not looking to race but would like a stronger one as I am increasingly upgrading my 92 convertible. Do you know if these trannys can be made stronger with the ASR? Thank you for your posts.
Do you have the FSM?
Safety Car
Joined: Apr 2016
Posts: 4,648
Likes: 1,059
From: N.E. Ohio OH
Finalist 2020 C4 of the Year - Modified
I would like to put in a stronger tranny in my 92. From your post I am gathering that the ASR is part of the transmission. I am not looking to race but would like a stronger one as I am increasingly upgrading my 92 convertible. Do you know if these trannys can be made stronger with the ASR? Thank you for your posts.
The 700R4/4L60/4L60E transmissions can be upgraded to hold as much HP as you realistically will be getting without major expenditures.
Read this:
https://www.sonnax.com/tech_resource...n-build-guides
Just like engine power is a direct derivative of Cubic Bucks, a strong transmission is a result of direct investment also.
Or you can look at Gear Star transmission, here in the Akron area for an upgraded trans,
https://gearstar.com/
Safety Car
Joined: Apr 2016
Posts: 4,648
Likes: 1,059
From: N.E. Ohio OH
Finalist 2020 C4 of the Year - Modified
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
5 MOST and 5 LEAST Popular Corvette Model Years in History!
Joe Kucinski
2027 Corvette Buyer's Guide: Everything You Need to Know!
Joe Kucinski
10 Things C8 Corvette Owners Hate (But Won't Tell You)
Joe Kucinski
10 Best Corvettes Coming to Barrett-Jackson Palm Beach 2026!
Brett Foote