'69 Turbo 400 code?

[SS427]

You guys are my last hope and maybe should have been my first. I recently looked at a '69 Chevrolet I was documenting with a turbo 400. It is definately dated 1969 (mid year) and has a yellow aluminum tag with "CY" on the side. (69-Y-xxx) I cannot find a "Y" code anywhere, only B, F, H and X for '69 turbo 400. It is NOT a '70 trans based on the tag date and is definately a Chevrolet trans. Someone please tell me what trans this is. HELP!!!

[YENKO DEUCE REGISTRY]

I don't see the 'Y' listing for the '69 applications either. The small note in the '70-'75 CBTN's book says that for the '70 TH400: "the assembly date code for the 1970 model year starts with the first day of the calender year in 1969 and continues through the 1970 calender. '372' is January 7, 1970."

What is your 3 digit date code? I guess if it's higher than 243 (Aug 31, 1969) it would be into the '70 build year??
M

[SS427]

YENKO DEUCE,
Thanks for the quick reply. Based on several facts, I am quite sure this is a '69 transmission. Number 1, the tag shows (69) for '69 "model" year, not necessarily the year of assembly. Page 288 of Alan Colvins "By the numbers" book states, "The assembly date code for the 1969 model year starts with the first day of the calender year 1968 and continues into the 1969 model year". I don't have that 3 digit date code in front of me, but based on the 69 in the top left corner of the tag, it is a 69 tranny as well as that is the car it is in. I will try to get that 3 digit date code. It does also has a VIN number stamped on the tranny that matches the '69 cars number.

Also, I believe the yellow tags were normally on the high perf trannys. I am at a total loss.

[JoeC]

The 1969 hi po TH400 is CX code. Post the numbers on your trans tag on pass side and look for a vin no. on the vin pad on driver side just above oil pan.

[Mr70]

On page 27 of the Sept./Oct.1969 Chevrolet Service News.
NEW CENTER SUPPORT AND SPACER RING-TURBO HYDRA-MATIC 400 TRANSMISSION.This change became effective with transmisson serial numbers and build date codes as follows:
CA-69-78912 date 464
CB-69-5477 date 465
CC-69-20716 date 464
CD-69-1309 date 472
CE-69-5693 date 471
CF-69-1057 date when built
CG-69-1403 date 472
CH-69-1011 date when built
CJ-69-12871 date 467
CK-69-4661 date 466
CL-69-1945 date 466
CP-69-5068 date 466
CQ-69-17771 date 465
CT-69-98319 date 465
CX-69-3312 date 479
CY-69-1723 date 478

This verifies that that trans.code is indeed legit in a 1969 Chevrolet car.I checked all the issues before and after this and it does not mention applications for these codes.But I would bet my eye teeth it is authentic for that SPECIAL Impala. http://www.yenko.net/ubb/smilies/images/icons/smile.gif

[Rowdy Rat]

"CY" coded transmissions were used in 1969 behind solid lifter Corvette applications - L71, L89, L88, and ZL1. This particular application is quite rare for Corvettes; I've been told the total number installed in 1969 was 255.

The specifications and internals of this transmission are identical to the "CX" transmissions.

Regards,

Stan Falenski

[SS427]

AHHH! I am getting closer, thank you Stan. It was my understanding that the Corvettes also used the CX transmission so that is a new one to me. Do you or anyone else have anything documentation pertaining to this Y code behind a Corvette or any other Chevrolet for that matter? Thanks again!!

[Rowdy Rat]

1969 Corvettes that were available with the THM 400 automatic transmission used one of three codes: CK for base engine applications (ZQ3), CL for hydraulic lifter 427 applications (L36 and L68), and the CY for solid lifter 427 applications (L71, L89, L88, and ZL1). To the best of my knowledge, the CY and CX coded THM 400s were practically identical... Revised valve body with higher shift points, fully welded torque convertor, six attaching bolts for the torque convertor, etc. In addition, Corvettes equipped with the CY automatic also received a special AX or CAX (depending upon when the car was built) code 3.36 to 1 ratio rear axle as the "performance ratio". I know of one L88/M40 that is said to have a 2.73 rear, but every other car that I have seen or know about has a 3.36. Nothing numerically higher was listed which is odd considering the fact that MANY Camaros and Chevelles with the CX transmission had 4.10s. For whatever reason, the automatic was never received well in the high horsepower Corvettes and as a result, very few were built. Resale on these 1969 cars is still substantially less than a comparable four speed car with the same engine and can be real bargains if you are able to find a nice one.

This CY transmission was also used behind 1971 LS6 Corvettes and was planned for use with the 1970 LS7 Corvette if it had been released for sale. As with the 1969 version, a 3.36 rear axle ratio was the highest numerical ratio listed.

I am not aware of any other application for the CY transmission... I guess that it would be possible, but I have not heard of any such usage outside of Corvettes.

What additional information were you looking for?

Regards,

Stan Falenski

[Mr70]

BINGO!!!
It took me a while,but I knew I had this.It is a 1969 Technicians Engineering Catalog.In house only.
It lists all the Engine,Trans.and rearend codes for the 1969 Chevrolet Carline.
It tells how to break down the Date codes as well.Even the transmission and rearends.In it it states:
CY-Coded TH400.
396/375HP Chevelle-Nova-Camaro
427/435HP Corvette
427/430HP Corvette
427/425HP CHEVROLET
All with High-shift point.
If you list all the numbers off of the tag,I can tell you the dates and other meanings as well.
By the way,I am curious as to the rearend suffix ratio.Do you know that as well?
Yes Yellow does mean Hi-Perf. http://www.yenko.net/ubb/smilies/images/icons/smile.gif

[Edited by mr70 (08-14-2001 at 05:56 PM).]

[William]

I have the engineering parts listing for all 1969 T400s. It shows a CY using a different case & valve body than the CX.

[SS427]

I knew I should have come here first!!!!!

I about wore my fingers out at the other sites and you guys come thru. As always Rick P. You Da Man!!! I really do need to get out to your place and "play" in your library.

The rear code is DK for 3.55:1 Posi with large ring gear. Also a plus.

Thank you everyone on the Supercar site. This will definately help me.
Rick

[SS427]

I don't have the tag in front of me but, it has a large "C" screen printed in the left corner. Than there is a stamped 69-Y-xxx (date). On the right corner is a screen printed "Y". The tag is yellow in color. At the bottom is a stamped number which I am not sure what those stand for. The cars VIN number is indeed stamped on the drivers side so I feel it is an original tranny. This is the missing puzzle if I can just figure it out!

[JoeC]

I have not heard of any 427 COPO cars with the CY trans. I wonder if the CY was only used with a 3 series rear gear and not the 4:10? There is a copy of a Chevy Bulletin dated 7-12-68 in the Colvin book page 291 on this new HD "high speed" THM400. It states that the trans will "accommodate engine speeds up to 7800 RPM" and Max upshift point is 6300 RPM. http://www.yenko.net/ubb/smilies/images/icons/shocked.gif
What was the code on the 1968 COPO L78 Novas? Also there is a question in the TECH section on what is the stall speed of the hi po torque converter. Anyone know? I could not find it listed anywhere.

[Ray Morrison]

Joe,
I have the same information on the tech bulletin dated July 12, 1968. Although the transmissions were called 69's since they were built just as the 68 models were winding down, this 400 transmission they have reference too I'm pretty sure is that of the CY code. The code on the Gibb Nova's are CY, however they do not have the yellow tag mentioned in an earlier post. They are green & silver. An interesting thing on these transmissions that I have noticed is the serial numbers on all that have been located with original documentation start at 100 and go upward with all these being below 50. Example, the serial number on mine is 1005 and the highest one that I have is 1041, presuming this to be number 5 and number 41? The protect-o-plate merely calls this transmission 68C100, but there is a big yellow CY painted in yellow on the upper right of the bell housing. The metal tag on the side of my transmission reads CY 68 1005. As far as the stall speed on the original Cy transmissions, I think it was somewhere around 2,000 rpm. These things were pretty tight. It is also my understanding that the CX transmission introduced on October 25, 1968 had a higher stall converter, and just a couple of small modifications to that of the CY. The transmissions built for the Gibb cars were built in June, which was just prior to the first 2 weeks of July that the Gibb Novas were all built. I would be interested to know what application that the CY transmission being discussed in this thread and the build date of that application to see if there may have been some cars built between the Gibb cars and the introduction of the CX transmission? Ray

[Chevy454]

Ray:

Long time no type! It's been a while, but it's glad to have you back. Sorry I missed you the other day, but dad and I did have a nice visit with Mike. Seemed like an awfully long lunch break...you must have been HUNGRY!

Anyway, I seem to remember Jim Mattison saying there were more than the 50 Gibb cars built with the 400th in '68. I want to say the number was right around 60(?), including the Gibb cars.

[JoeC]

Hello Ray, thanks for the reply. The 1005 serial no. is interesting. Did the later (07+) 1968 L72 Impala or the 1968 L71 L88 Corvette use the CY TH400?
"elcamino" posted on "chevy talk" that his Chevy books listed the 1969 CY application as;
Y - 427 335 HP Chevrolet
Y - 427 425 HP Chevrolet
Y - 427 430 HP Corvette
Y - 427 435 HP Corvette
Y - 396 375 HP Chevelle, Nova, Camaro
Anyone have the list for 1968?
Was the CX trans only used in 1969 427 COPOs? If so, the CX trans serial no. may give a clue as to how many 427 TH400 COPO cars were built.

[Rowdy Rat]

Joe,

As far as Corvettes, I can tell you that the "CY" code THM 400 was only used behind the solid lifter big blocks in 1969; it was not offered as an option in 1968 for use with the L71/L89/L88. I'm also curious as to the 335hp 427 application you listed. Why would a low rpm utility engine need a high rpm shift point automatic?

Your description of the "CY" code automatic for the 1968 COPO Novas sounds quite a bit like the Corvette unit in 1969... 6200-6400 rpm full throttle upshifts.

William,

Your comments regarding different part numbers for the case and valve body were enlightening... I had always been told that the Corvette "CY" and Camaro/Chevelle "CX" automatics were nearly identical. If it isn't too much trouble for you to look them up, I would be very interested to learn what the part numbers for "CX"/"CY" transmissions were for the torque convertor, valve body, and case. I would appreciate any information that you can provide.

Regards,

Stan Falenski

[SS427]

Stan, I too found the information last night (had it all the time and didn't know it!) My information also listed the "Y" code for 335 hp. I am clueless as well and have owned numerous 335 hp motors, none of which had the "Y" code. If true, I suspect it was so that the car could get out of it's own way. The transmission likely comensated for the low horsepower of the engine.

I hope to get all the numbers off this transmission in the near future. I am also curious to see if it has 6 torque convertor bolts. Incedently, this is in an Impala.

[Rowdy Rat]

Rick,

I figured it was a "big" Chevy from your previous posts... I gather that this is a 1969 L-72 car? Very cool if it is! I've been hunting for a 1969 L-72 Biscayne, Bel Air, or Impala for a while now... Not many out there as I'm sure you're aware. I'd love to hear more about your car when you get the opportunity.

I don't disagree with what you and others have located in print about the "CY" transmission usage with the 427/335. I would guess that it might be a mistake (unless the "CY" transmission used in this application is VERY different than the other applications listed). You mentioned that that this is a low horsepower engine; it is also a low rpm engine. I'm sure that someone will post the redline, but I'd be willing to bet that it is 5,500 rpm or less. With a redline (and powerband) that low, why do you need a transmission that shifts at 6200+ rpm? Logically it doesn't make much sense. I'd like to hear some feedback on this point as well...

Regards,

Stan Falenski

[Mr70]

My information shows the 1969 427/335HP Chevrolet as getting the CQ Suffix.Not the CY.
It states this code for only that L-36 engine.
1968 list shows CE as the trans.for Chevelle-Camaro with an L-78 engine.CL for the 427 Corvette.No CY or CX in 1968.
The CY trans. was avaiable before the CX was in 1969.
The CX was the trans.in the letter dated 7/12/68 in Colvins book.It was used,as the letter states,in 1969 Special Hi-perf Engine Novas,Chevelles,Camaros,Chevrolet,and Corvette.It looks COPO specific and L-72 Impala or Corvette L-71 and up also got it.
I have seen the CX in a 69 COPO chevelle with a 4:10 Posi.I believe it was specific to these rear ratio cars in 1969.

In 1970 the CY was the trans.of choice for the Hi-perf LS-6 engine.All the LS-6 M40 buildsheets have the CY code available with ANY rear ratio.Not just 4:10.Although I think the 1970 Corvette could get the CX still.Any Corvette documentation out there to prove this?


[Edited by mr70 (08-16-2001 at 01:58 PM).]

[William]

Stan, the CX & CY use converter 8626358. They also use the same valve body 8624854, but different control valve assemblies.

CX uses case 8623457, valve assy 8626613.

CY uses case 8626058, valve assy 8626367.

CX & CY have other internal parts not used on other versions. The cases aren't unique.

[Ray Morrison]

William,

The casting number on my CY coded 400 is 8623462, the short tail housing is 8624486.

Stan, I still believe the Transmission Identification sheet of 7-12-68 is for the CY code transmission as they came before the CX. Could the X on this document be the reason you think it is for the CX? The Gibb cars were built with a redesigned Turbo 400 for racing purposes. These first redesigned 400's were called experimental automatics (X). These transmissions are believed to be the first automatics built for Chevrolet with a high horsepower, solid lifter engine. According to documents I have, 39 pages of Hydramatic Production Parts list, the CX code was added on 10-25-68, meaning they were built for 69 cars. Would Turbohydramtic have issued this letter this far in advance on building the CX? If any of you have the November 1968 issue of Popular Hot Rodding and the article about the Harrell Novas, notice in this article they refer to the experimental transmission as 69's, however, we now know the Gibb cars were built on the tail end of 68 with these transmissions as a COPO Nova, which was never mentioned in the article. Both the Cy and CX coded transmissions shared likness in that they were built for high performance applications in 68 & 69, L-78's, L-72's, etc. Could some of the extra experimental transmissions have been built for Gibb, or someone else? Since Mark Fuss has a Harrell Nova that is an automatic, Which is not one of the 50 Gibb COPO's, but could Harrell have built his car with one of these? His Nova supports an L-88 engine. How many other Experimental Automatics could have been built for warranty? There are all kinds of questions that are still unanswered?

Ray

[Ray Morrison]

William,

The casting number on my CY coded 400 is 8623462, the short tail housing is 8624486.

Stan, I still believe the Transmission Identification sheet of 7-12-68 is for the CY code transmission as they came before the CX. Could the X on this document be the reason you think it is for the CX? The Gibb cars were built with a redesigned Turbo 400 for racing purposes. These first redesigned 400's were called experimental automatics (X). These transmissions are believed to be the first automatics built for Chevrolet with a high horsepower, solid lifter engine. According to documents I have, 39 pages of Hydramatic Production Parts list, the CX code was added on 10-25-68, meaning they were built for 69 cars. Would Turbohydramtic have issued this letter this far in advance on building the CX? If any of you have the November 1968 issue of Popular Hot Rodding and the article about the Harrell Novas, notice in this article they refer to the experimental transmission as 69's, however, we now know the Gibb cars were built on the tail end of 68 with these transmissions as a COPO Nova, which was never mentioned in the article. Both the Cy and CX coded transmissions shared likness in that they were built for high performance applications in 68 & 69, L-78's, L-72's, etc. Could some of the extra experimental transmissions have been built for Gibb, or someone else? Since Mark Fuss has a Harrell Nova that is an automatic, Which is not one of the 50 Gibb COPO's, but could Harrell have built his car with one of these? His Nova supports an L-88 engine. How many other Experimental Automatics could have been built for warranty? There are all kinds of questions that are still unanswered?

Ray

[SS427]

mr70,
The car was built in December '69 which might correlate with your statement about CY preceding CX in '69. The rear is an 3:55 large ring posi and I am positive it is the original rearend.

I need to get more numbers off the car, see if it had a tach (I don't think I would have missed that ugly thing) and check the speedo for the max speed. Many of the L-72's I have seen had 140 speedos in them. I still need to find a build sheet somewhere!

[Rowdy Rat]

<BLOCKQUOTE><font size="1" face="">quote:</font><HR>My information shows the 1969 427/335HP Chevrolet as getting the CQ Suffix.Not the CY.It states this code for only that L-36 engine.<HR></BLOCKQUOTE>

That certainly makes a lot more sense...

<BLOCKQUOTE><font size="1" face="">quote:</font><HR>The CX was the trans.in the letter dated 7/12/68 in Colvins book.It was used,as the letter states,in 1969 Special Hi-perf Engine Novas,Chevelles,Camaros,Chevrolet,and Corvette.It looks COPO specific and L-72 Impala or Corvette L-71 and up also got it.
I have seen the CX in a 69 COPO chevelle with a 4:10 Posi.I believe it was specific to these rear ratio cars in 1969.
In 1970 the CY was the trans.of choice for the Hi-perf LS-6 engine.All the LS-6 M40 buildsheets have the CY code available with ANY rear ratio.Not just 4:10.Although I think the 1970 Corvette could get the CX still.Any Corvette documentation out there to prove this?<HR></BLOCKQUOTE>

I've had the opportunity to look at quite a few 1969 Corvettes equipped with the high performance engines (L71, L89, and L88) and automatic transmission. Without exception, they have all had a "CY" code. If "CX" was somehow linked to a 4.10 rear axle ratio, that would certainly explain why the Corvettes didn't receive it. As I mentioned previously, the highest numerical ratio that could be ordered with the big block and automatic transmission was 3.36; the high performance 427s received a "special" differential with its own code of "AX" (or "CAX" depending upon how late in 1969 the car was built). As far as 1970, my understanding is that had the LS7 Corvette gone into production, it would have used the "CY" transmission along with the same "CAX" rear axle (at least the power team chart for 1970 Corvettes show a 3.36 ratio as the "performance" axle with the the LS7/M40 combination).

You and Joe both touched on a possible transmission - rear axle relationship... Could this have determined which was used for a given application?

Regards,

Stan

[Rowdy Rat]

William,

Thanks for posting the part numbers... I certainly appreciate it!

<BLOCKQUOTE><font size="1" face="">quote:</font><HR>Stan, I still believe the Transmission Identification sheet of 7-12-68 is for the CY code transmission as they came before the CX. Could the X on this document be the reason you think it is for the CX?<HR></BLOCKQUOTE>

Ray,

To be honest, I'm not familiar with the document you are referring to and I don't have a whole lot of background information on the Gibb Novas or the special THM 400s so I'll defer to you and others on that topic. http://www.yenko.net/ubb/smilies/images/icons/smile.gif My comments referred exclusively to 1969 Corvettes that used the "heavy duty" THM 400. The cars that I have observed have all been "CY" code ranther than the "CX" code used by the 1969 COPO cars.

Regards,

Stan

[JoeC]

To sum it up a little, The CY trans was used in 68 69 and 70? The CX trans is 69 427 COPO only? Anyone know of any CX trans in a non-427 COPO car?

[Chevy454]

OK, fellas, here is part of the documentation Ray has: 400TH INFO (http://ortrackm.missouri.org/~yenko/HYDRAM~1.jpg)

[SS427]

Ok, went out this morning and verified a few more numbers, good news!

CY-69-1448 built 334th day of '68. Perfect for a December '69 car. It did have 6 torque convertor bolts as well. Looks to be 100% legit. Sad thing is, he won't sell!

If nothing else, I now know where to come when I need legit real information.
SuperCars

[William]

The CX may have morphed into CW for 1970.
I believe that is what the 1970 Z28 used.

A friend has a COPO Camaro; the pop shows a CC trans...

[Mr70]

I must say this topic is getting very interesting for me.It all started on one mans outside inquiry.
Also to sum up:
The CY was definately used in 1970 LS-6 Chevelles,and up to 1974.
The CW was used on my L-78 1970 Chevelle,up to 1972.

CY first,then the CX later.
Rays documents look convincing for me to believe the CY trans was used in the 1968 Gibb Novas.The CY trans.was the one mentioned in the 7/12/68 letter.Not the CX as I thought.

The CX trans. wasn't out till 10/25/68.And COULD be specific for 427 COPO cars with 4:10 rears only?We need to look at serial #'s at the reunion for this,which I hope to attend.

A December built 1969 L-72 Impala used the CY trans.and not the CX.

The 1969 Special Hi-perf Corvettes used the CY code trans.,and not the CX.

I have never seen the CX trans.used in the 1970 model year.So it may be safe to say it was only used in the 1969 models.
Rick




[Edited by mr70 (08-19-2001 at 12:31 PM).]

[Mr70]

Cmon SS427,get him to sell it to you.
Sounds like you would enjoy it more then he would. http://www.yenko.net/ubb/smilies/images/icons/wink.gif

[YENKO DEUCE REGISTRY]

ss427;
Did the trans have the VIN# stamped into the pan rail?
M

[SS427]

No, I went out again Saturday and spent another few hours checking the car over. No VIN # on tranny (which is quite common), had Tonowanda stamp, date and engine prefix on engine but no VIN number on pad in front or by oil filter. ALL dates codes of All components (excluding water pump, fan and radiator) matched car within allowable time spans. A week ago, I also had another historian and documentation expert with me and he concurred.

The car is VERY rough and I found absolutely NO reason or clue that the car was/would be a fake. I have been restoring/documenting cars for twenty five years and to the best of my abilities, this is no fake. Its a moot point as he won't sell and possibly won't restore the car.

This car is also manufactured in New York and delivered on the East Coast and might have some history but that has not been verified yet.

One hell of a find and a neat piece of history only a few can appreciate but not at this time. I can only pray it gets back on the road fully restored because of its rare existence.

[YENKO DEUCE REGISTRY]

SS427;
What kind of hood is on it??
M

[SS427]

It has a stock '69 Impala hood. I have never seen anything different, even on B/M cars. Maybe you didn't know I had been talking "Impala" all this time.......or did they have a special hood on these cars? I have never seen any reference to this before.

I do not however have any reason (yet) to suspect this is a B/M car or anything else for that matter. It's a bench seat/column shift car for one thing and VERY heavy.......

[Mr70]

Is it a convertible too?

[SS427]

Did I say that???? Funny YOU should mention that. Yes it is a convert. That's what makes it so rare. I have never seen or heard of one in twenty five years of collecting and researching these cars. It would be really neat if this had some East Coast history.

Some of you are likely cringing at the thought of driving a boat but this is one rare bird with high performance to boot.

By the way Rick, got your photo copy today, thank you. It is a little different than the one I found. A cold one commin' at ya!

[YENKO DEUCE REGISTRY]

ss427:
I figured you were talking about an impala from your first post when you called it a 'chevrolet', instead of camaro/chevelle/ect....

We knew that the COPO Novas received a 'CY' trans in '68, along with the hi-po Vette's in '69, and various models in '70 after researching what the COPO Novas came with in '70. However, I did not know that an impala could have come with a 'CY' trans in '69. Very interesting car that you found.

I thought that the SS Impalas had different types of hood grilles in the center of the hood, depending on the particular year, (?). I remember seeing a black ss427 convertible from New York City at the PSMCDR a few years ago, it had some amazing wheelhop problems!
Marlin

[SS427]

Marlin, I got excited when I first saw the car but got really excited when I found the CY prefex. To the best of my research, this is quite possibly one of one as a convertible. Thats only important if you are into HEAVY performance. I am into rare cars as a whole so it's a moot point. I would love to restore this car because of it's rarity.

As I currently own all three years of the Z-24 SS427 option (67-69), this would also be a nice addition to my collection. You are correct in the hoods for the most part. '67 used a 'tear drop' dome on the hood with 3 simulated chrome openings, '68 used a raised 'cowl type' portion to the hood with a chrome vent at the rear of the hood. However, 69's did nothing to the hood to signify the SS427 Z-24 option as it was an option deleted in that year and they put no more money into them than they had to.

This is probably way more than anyone here cares about Impalas but they are rare to say the least. The average production of all three years was around 2000 issued. The hoods alone today are worth around $1500-2500 IF you can find one.