TH400 rebuild kits

[Matti Roth]

Hi!

I plan to install rebuild kit toTH400 transmission in my 64 DeVille. I can find several kits available for 65 onwards, but not that many for 64. I wonder what are the differences in 64 and 65 rebuild kits, if any?

thanks in advance!

[Matti Roth]

Thanks Mark

There is no switch pitch in 64. 
Please note I am based in Finland, so all costs and delivery times get much bigger when buying from US. I will check Fatsco offering.

[Matti Roth]

I checked Fatsco website, and there are very useful catalogs where you can compare the parts for different years. It looks like there are more than minor differences between 64 and 65->. Even the valve body is different from rest of the production. Thanks Mark !!

Is it really so that there is no engine serial number /vin stamped in 64 TH400, like it is in later years? No chance to check if the gearbox is original.

[Jason Edge]

As noted in our Engines and Transmission Facts Help Page  The 1964 Turbo HydraMatic was a Buick borrowed Super Turbine 400 transmission, which is the reason for the adpator ring to allow it ot mate of to the back of the 429 Cadillac Engine.  The help topic also notes:

 For 1965, the bell housing casing was changed to allow the transmission to mount directly up to the 65 429, and the internal hydraulic circuitry was modified to provide a dual drive range as seen in the 1965 Cadillac Shift Quadrant below. 

With that said, in Fig 1-1 in your 1964 Cadillac Shop Manual (hopefully you have one), you will see the Turbo Hydramatic has a Unt Number on a plate on right side.  As further noted on the 1st page of the Turbo Hydramatic Chapter on page 10A-1 it notes the ID plate, it states a C and D or C and F appear above the serial number.

NOTE this is not the Engine Serial Number (VIN) and is instead a sequential production number for that THM transmission. Since there is a % of 1964's (Series 62, Series 75, Commercial Chassis) that received the older Hydramatic Transmission even looking at this # comparativedly to the overal production # (165,959) doesn't give you much information. You can add up all 1964 models with the THM Transmission (126,816 if my math is right), divide that # by the THM serial #, then multiply that % time 165,959 to get a approximation of the  Engine Serial Number (VIN) the particular transmission was coupled with... but that is not going to be exact as I am sure 1) the production distribution of THM/HM cars was not 100 % linear against the % produced over the entire year, and there would have been discarded/extra engines/transmission meaning the #'s would not have been an exact match. 

The best way to know if your Turbo Hydxramatic is a 1964 or a later version would be 1) look at the ID plate 2) determine if it bolts directly to back of transmission (if yes it is 1965 or later, if not, probably an 1964), 3) look at number of wires going to the transmission (1 wire would be for the 1964 non-switch pitch transmission; 2 wires/leads would be for the 1965 or later with the switch pitch with a separate wire to the switch pitch solenoid/relay (if my memory serves), and 4) determine if it has 2 Drive range in addition to the L range as seen in the 1965 shift quadrant abo ve. There are probably other wayst to tell the difference to between 1964 and 1965 & later, but the bolt pattern and 1 wire vs 2 wire connection comes to my mind first.

[Matti Roth]

Thanks Jason,

TH400 in my 64 Deville is clearly 64, but I am interested if it iis the original one, assembled to this car at the factory. Like in my 71 Eldo and 79 Seville, there is Vin stamped in the transmission housing. But it seems that in 64 that is not the case.. So we can not confirm ”matching mumbers”.

[Jason Edge]

Since Engine Serial Number (called VIN in 1965 and later) was not stamped on the trans, the best you could do would be to disprove it came from your car by correlating the ESN with the Trans Unit #. If you had a very out of range (maybe more than 10%) # you could probably conclude it did not come from that car.

Like most other items on the car you would often have a casting # (not to be confused with a Cadillac "Part #" which was often different), and for a dozen items in 1964, you had unique Unit # or Serial #'s as seen at the front of the 1964 Shop Manual below. In addition the idea of a VIN # was evolving, and as just noted, was first used in literature, etc in 1965 model years. For more history on the VIN # check out this Help Topic:
VIN: Where's the VIN?

 

 

[Jason Edge]

Just to add there were grease pencil markings found on many items on these cars but they were usually the last 2 digits of the car’s ESN/VIN and never recall seeing one on a transmission if they would have survised anyway. 
For example, the last parts car I parted out was VIN 64N136767 and the number "67" was grease marked on many behind the dash parts like the radio and instrument panel bezel, etc. and sometimes see them on under hood items but not as often. Of course that only gives you 2 digits and would only give you a pretty good degree of certainty it came from that car unless you are sure your are disassembling or removing something for the first time.  There is also a chance the your or prior owner took pictures of any prior transmission removals that show the Trans Unit #.  Probably a very slim chance of that, but I think I have documented just about every angle of my 64 CDV and wouldn't be surprised if I don't have a picture of the original Trans and Unit #. I run a rebuilt 64 THM from a parts car I pulled in so it would not be something I would be chasing after anyway. 

OH, one other thing... there often date codes on many parts... month and year. Some people like to match parts date stamps to the month/year of car manufacture even if it does not have an ESN/VIN stamped on it.