Question About D32 vs D34 on Fender Tags.

Wildaugust

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I've been wondering for a while about the trans codes on the fender tags, so I thought I'd ask the experts.

I see quite a few C-Body tags showing D32, which is the code for the "Heavy Duty" 727, if I'm not mistaken. I also see tags with the D34 code, which is the code for "Standard Duty". It seems to me that nearly all of the 383 or 400 equipped cars have the D32 trans code and I have also seen the D32 on the fender tags of 440 powered cars. The thing that has me puzzled is when I see a D34 code trans behind a 440. If the D32 is the heavy duty trans, why would so many of the 383 and 400 cars get it while some 440 equipped cars got the standard duty (which I assume means lighter duty) D34 trans?

Do all D32 transmissions have the same internals? In other words, would a D32 that came behind a 383 have the same guts as a D32 that came in a 440 car, or would a D34 transmission that came with a 440 actually be a beefier trans than a D32 that came out of the factory attached to a 383 or 400 engine?

Just curious.:)
 
I believe the one code superseded the other ie D32 was replaced with D34, I say that as my 69 with 318/727 has the D32 code, but my 73 with 318/727 has the D34 code.

I however am likely incorrect.
 
I've been wondering for a while about the trans codes on the fender tags, so I thought I'd ask the experts.

I see quite a few C-Body tags showing D32, which is the code for the "Heavy Duty" 727, if I'm not mistaken. I also see tags with the D34 code, which is the code for "Standard Duty". It seems to me that nearly all of the 383 or 400 equipped cars have the D32 trans code and I have also seen the D32 on the fender tags of 440 powered cars. The thing that has me puzzled is when I see a D34 code trans behind a 440. If the D32 is the heavy duty trans, why would so many of the 383 and 400 cars get it while some 440 equipped cars got the standard duty (which I assume means lighter duty) D34 trans?

Do all D32 transmissions have the same internals? In other words, would a D32 that came behind a 383 have the same guts as a D32 that came in a 440 car, or would a D34 transmission that came with a 440 actually be a beefier trans than a D32 that came out of the factory attached to a 383 or 400 engine?

Just curious.:)

D32 for '69-71 is the HD A-727, D34 for 69-71 is usually the light duty small block version of the A727. The HD versions usually had heavier clutch packs and bands. Some years the HD version is D36. and some years the A-904 is D34. It all gets confusing. The B-Body website has a good write up for identifying the differences between the transmissions, but they do not go into build tag codes. "Your guide to the 727/904 Transmission". www.forbbodiesonly.com. The light duty A-727 was a small block or 6 cylinder only application.

Dave
 
I've been wondering for a while about the trans codes on the fender tags, so I thought I'd ask the experts.

I see quite a few C-Body tags showing D32, which is the code for the "Heavy Duty" 727, if I'm not mistaken. I also see tags with the D34 code, which is the code for "Standard Duty". It seems to me that nearly all of the 383 or 400 equipped cars have the D32 trans code and I have also seen the D32 on the fender tags of 440 powered cars. The thing that has me puzzled is when I see a D34 code trans behind a 440. If the D32 is the heavy duty trans, why would so many of the 383 and 400 cars get it while some 440 equipped cars got the standard duty (which I assume means lighter duty) D34 trans?

Do all D32 transmissions have the same internals? In other words, would a D32 that came behind a 383 have the same guts as a D32 that came in a 440 car, or would a D34 transmission that came with a 440 actually be a beefier trans than a D32 that came out of the factory attached to a 383 or 400 engine?

Just curious.:)


What you are seeing is a change in coding over the years.

In 69, 70 and 71, Codes D31 and D32 were used to distinguish between the 904 and 727 versions of automatic transmission. The code tells you 'what' not 'which'. The D32 transmission behind a 383-2 was still coded D32 but it was certainly not the same transmission as the one behind a Hemi, which also coded D32.

I have seen D34 used on, interestingly, very early 69 and 70 pilot or promo cars. One can also find D34 on 71 340 cars built at the Windsor plant. By far, these are exceptions between 69-71. Most cars will code D31 or D32.

Coding changes in 1972 as all automatic transmissions, from /6 to 440-6 cars code D34. Again, this code only tells you the 'what', an automatic transmission, not the 'which'; the specific part number and application of a transmission.

I've seen D32 used on a 72 fleet car and a couple of other 73-75s but, by far, the most common automatic transmission code is D34.

Tag coding changes again in '76.

What is coded on the window sticker or broadcast sheet may be different that what is coded on the tag. Again, you have to take into account what year you are talking about as things change year to year.
 
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That "style" of coding makes it easier for the sales operatives. Coding a "3-speed automatic", rather than a particular automatic trans variation per se. Basically, let the engine selection determine the transmission (as on the build sheet?) rather than the person doing the vehicle ordering. If the vehicle was officially a "fleet vehicle", including the VIN associated with the genuine law enforcement vehicles, that might trigger a more HD version, too. As might a HD Trailer Tow Package option.

Chevy used to code their 3-speed automatic transmissions by "type" (i.e., THM350 = M38 and THM400 = M40), but that changed in the later 1970s with TWO codes. One was the "sales code" on the window sticker for 3-speed automatic transmission and the normal code, along with the sales code, on the build sheet. This was eased-in on the '77 or so Caprices, when you could not specifically code a THM350 or THM200 automatic, when the customer suspected it would have a THM350, as in the past.

As for the "HD" nomenclature, it might be good to consider that a "point of reference" might be needed to fully understand this. "HD" compared to what? Not unlike the "High Performance" nomenclature on 383 4bbls (i.e., 383 "N" code of 1970). "HP" compared to the 383 2bbls, I suspect for the 383/330, but more true with the 383/335 vehicles. The 383/330 (old) "Standard Cam" 256/260) was more high performance than the earlier 252/252 cam from the 1958 era, which also came on 383 2bbls. Back when adding a 4bbl was "high performance" or "Power Pak".

End result, consider the transmission type along with the engine in front of it to gauge "HD" or "normal 2-bbl" version, I guess. Which might work better than looking solely at the tag codes?

Enjoy!
CBODY67
 
Up to the end of C-body production the transmission codes seen on fender tags are:

D34: Belvidere 1972-1975, East Jefferson 1972-1975 and 1977-1978, Newark 1972-1974
D36: Belvidere 1976-1977, East Jefferson 1976

As a consequence, in 1977 Chrysler tags can have two codes: Belvidere-built Newport and Town & Country have D36, whereas East Jefferson-built Newport and New Yorker Brougham have D34.

The 1977 Plymouth Police Cars brochure doesn't mention a heavy-duty transmission. It only states: "Automatic transmissions are specifically matched to each engine. ... TorqueFlite used for police duty has an auxiliary oil cooler as standard equipment." Also, the Dealership Data Books for wagons at The 1970 Hamtramck Registry make non mention of a heavy-duty transmission, neither as a standard feature, nor as an item included in the Trailer-Towing Packages. So it realy boils down the broadcast sheet if you want to find out.
 
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The broadcast sheet for a 1977 Town & Country without Trailer-Towing Package has:

Trans D34 = "Std Duty A/Trans"
Trans D36 = "A727 A/Trans"

That explains why D34 and D36 can be used indiscriminately on fender tags. D36 specifies D34.

Then we come to the part numbers in the broadcast sheet:

Tran 424 = "4028424"

Per moparts.org that means:

4028424..........440..........727..........standard


As opposed to a broadcast sheet for a 1977 Gran Fury police car:

Trans D34 = "Std Duty A/Trans"
Trans ??? [unreadable, but the fender tag has D36 = "A727 A/Trans"]

Tran 425 = "4028425"

which is:

4028425..........440..........727..........high performance


So an A727 can be standard or high-performance (= heavy-duty?).
 
The broadcast sheet for a 1977 Town & Country without Trailer-Towing Package has:

Trans D34 = "Std Duty A/Trans"
Trans D36 = "A727 A/Trans"

That explains why D34 and D36 can be used indiscriminately on fender tags. D36 specifies D34.


So an A727 can be standard or high-performance (= heavy-duty?).

Good posts.


The D** codes simply tells you the 'what' = automatic transmission.

They don't tell you the 'which' or the specific transmission for that application. (Except for Lynch Road tags BUT the topic is C bodes....)
 
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