Where is '69 Corvette serial # location on tranny

[TOYVET]

Hello;
Going to look at a '69 427/400 Corvette tomorrow...need to know where to look for the car's serial # on the transmission casing. It is a Turbohydramatic (TH ) tranny..Thanks to all;
Greg

[Mr70]

On the drivers side,Check below the cable linkage,behind the rubber boot,just above the pan lip.You should see a recessed Horizontal machined pad displaying reminants of the VIN#.
If not there,look around the bell housing area too.

[KevinCav]

Greg,
You should also look at the Data tag on the passenger side of the trans.--it will be riveted to the passenger side of the trans case at about the mid-point. For a 69 427 Corvette
the codes MUST be either CL (for a 427/390 or 427/400) or CY (for a 427/430/435--L71,L89,or L88) If it is CK, this is the Turbo 400 for the 69 small block Corvette. Be very careful looking at these codes and the Vin #---the Vin # can be VERY hard to locate and even harder to view because of many things blocking your line of sight. Many of these transmissions were changed over the years and I have looked at a number of L71 and L89 auto Corvettes over the years and they very frequently have the trans changed. The owner/seller of the car usually swears it is the original trans, but if it is not the correct codes as mentioned above and the correct VIN #,,,it is NOT the original Trans., no matter what they say. If it is a CY code , contact me and I will tell you other things to look for---these are extremely rare transmissions---I had one for many years in a 69 L89 Corvette I owned--- what a combination!

[Bigblockhappy]

Kevin,

I have a CY transmission in my 70 LS-6 chevelle, is it correct?

Louis

[KevinCav]

Louis,

I am not familiar enough with the Turbo 400 codes for the Chevelle line to say that a 70 LS6 should have a "CY" Turbo 400, but it definitely seems appropriate. I know I have a spare "CY" under my bench that I'm pretty certain came out of a very, very early 71 Z28 from the Buffalo, NY area. I think you should match the Vin # on your trans to the car Vin to make sure it's the original transmission. If it matches, congratulations!

[Mr70]

Your Both right,to a point.
CY was not used on those 69 Vette Engines,CX was.
The CY TH400 was new for the 1970 LS6 Chevelles,& 1971 LS6 Corvettes.
It was continued into the 1972 350/255Hp Camaro,1973 350/245HP Z28,& 1974 350/245Hp Z28 too.
Check the Aluminum Passenger tag for a date code.

[KevinCav]

Mr70
I respectfully disagree due to the following;

1. My all original drivetrain, 1969 L89 Corvette, Vin # 194379S71753X (I don't own it anymore so I won't give the last digit) was equipped with a "CY" Turbo 400 that was serialized to the car's Vin. This Corvette was assembled on Feb. 27,1969. The data plate on the side of the trans. shows the following data: "401" next to the attaching rivet. This I believe indicates the assembly date of the trans. as Feb. 5,1969. On the left side of the tag is the large letter "C" and on the right side of the tag the large letter "Y"--both in light blue. The whole tag is painted in a light yellow color. Across the bottom of the tag is stamped "CY-69-1582" which I believe (but not sure) indicates the 1582'd unit assembled. As a side note, this car was originally from the Cleveland, OH area and when I sold it about four years ago it was extremely original, down to hose clamps and belts etc! What a mistake!
2. The NCRS (National Corvette Restorers Society) has long recognized the "CY" Turbo 400 as the correct trans. for 1969 Corvettes equipped with L71, L89, and L88 engines and Turbo 400 trans. This can be seen in their latest Judging Manual (Third Edition--violet color cover) in the Chassis section on page 86.
3.In the mid-90's a Corvette person from Cumberland, OH (Tom H.) was researching automatic equipped L71 and L89 1969 Corvettes and at the time he had only located approximately 8 vehicles. All of these Corvettes surveyed indicated they had a "CY" trans. The earliest assembled Corvette in the survey was built on Sept.7, 1968 and the latest Corvette in the survey was assembled on August 13, 1969.
4. The spare "CY" trans under my bench has the following on the data tag--The whole tag is painted light blue with medium sized letters "C" on the left side and "Y" on the right side. These letters are not painted on--they show the bare aluminum of the tag itself. "71Y" is to the left of the mounting rivet and "244" is to the right of the rivet. I believe this indicates an assembly date of Sept.1,1970. Stamped across the bottom of the tag is "71 CY 1425" which I believe indicates that this is the 1425th unit assembled. The Vin # derivative stamped into this trans is 11N52461# and I believe it came out of a 1971 Z-28.
Anyone else have any input on this topic?

[Mr70]

You're right.I stand corrected.
I am not as familiar with Corvettes,as I thought.I called a man here who referenced the NCRS Booklet,and it was as you described.
I never saw a CY trans in a Corvette,so can you tell us how many have been found to date?
I would be interested to learn more about them,did they keep records of how many recieved them from the Assembly line?
Did their Convertors have a 6 bolt configuration as well?

As for the 71 Z28,I believe you as well,as you have it physically in front of you,but what was the actual three letter engine suffix it was attached to,is it a CGR,or CLB?
Thanks for setting the record straight,and Welcome to the board.

[KevinCav]

Mr70
I don't know if anyone knows exactly how many "CY" Turbo 400's went into Corvettes but I believe they were only installed in 1969 L71,L88 and L89 Corvettes and then again they were used in the 1971 LS6 Corvettes. I have heard that there were supposedly 17 L88 automatics( LV suffix) built in 1969 and I suspect there were approximately 43 L89 automatics (LW suffix) built in 1969( I base this on info that was presented at an NCRS meet in the late 1980's by a fellow (Fran P.)who was an engineer at the Tonawanda plant and had exact counts on how many of each engine was produced by suffix code). In the 1980's and early 90's I was very closely tracking L89 Corvettes and had located approx. 85 of them (10 1967's--35 1968's--41 1969's)and at that time 8 of the 41 1969's that I had located were automatic L89's---however not all of them still retained their original "CY" transmissions. I suspect that there were considerably more "CY" L71 Corvettes built, possibly as many as 300-350, but this is merely a guess on my part( I am not aware of anyone that has ever tracked or surveyed these cars). If these numbers are close (and I know the L89/L88 numbers are almost exact) that would put the total at somewhere around 375 to 425 "CY" equipped 1969 Corvettes( approx. 1% of all 1969 Corvette production). As far as 1971 LS6 Corvettes, I know there were 188 of them produced, but I don't have any idea how many were "CY" equipped. I suspect again that it was a small amount, possibly 30-40 of them.
Was this person you spoke with from the NCRS Terry M.?
Yes, these "CY" transmissions use the 6 bolt torque converters, as I believe all the "CY"'s did. These really were heavy duty units. Mine was totally stock and it would shift at about 6100 RPM. Even today, I don't believe people understand what a potent combination they produced when coupled with a solid lifter, square port big block! Everyone seems to be blindly committed to the 4 spds.

As far as the "CY" I have from the 71 Z-28, I believe the suffix would have been CGR---I don't even know what application the CLB code is for. I know VERY little about Camaros---thats why I like this website so much--I'm constantly learning. I am thoroughly impressed with the knowledge and willingness to help by all the participants--like yourself, true gentlemen.