1950s 40's, 50's or 60's Transmission identification

[Cadman-iac]

I'm trying to figure out exactly what this transmission is that I got years ago.
It's got a cast iron case, a side cover that the shift shaft and throttle linkage goes through, and the oil pan is rectangular but is tapered with the right side being taller than the left.
The torus front cover is missing, so you can see the inside, and the "bell housing" part is not deep enough to cover the entire torus assembly. Kind of like the transmission fits an engine with an extention on the back of it.
The dipstick says Hydramatic on it and to use Cadillac Hydramatic fluid or Armour qualified type A fluid.
The data tag or ID tag is long gone, and it's got a rebuilders tag attached, but it's illegible other than the stamped serial number on it.
There's also a vent above and behind the torus on the "bell housing" about 6 or 7 inches wide and 3 inches tall.
The case has a cast number on the right side of 8615013 if that helps.
I'll try to get some pictures later, it's not where I can get a decent shot right now so I've got to move it.
It doesn't look like the ones in my 55 or 56, those don't have a side cover.
Any help is appreciated.
  Rick
 

[Cadman-iac]

 Here's some pics of the transmission. I was even wondering if it might be from a GMC with a V6 in it, but not sure if it was if it would have Cadillac on the dipstick.
 I checked the 64 Oldsmobiles I've got and they're not the same either, but the stick does say Hydramatic on it.

[Cadman-iac]

[Cadman-iac]

Here are a few more pictures of this thing. From what I've been able to find in my small library, and from looking at my 55 and 56's, I know this transmission is no newer than a 55, due to the side cover, but I believe it's probably from around the mid 40's to maybe early 50's.
 I've searched every service manual, motors manual, for car and truck, and I haven't found anything on one with a lopsided oil pan.
 Maybe these other pictures might help someone identify exactly what this is.
 Take a look and let me know if you know what it might be.
 Thanks, Rick

[Lexi]

Hey Cadman-iac, you preparing for a massive garage sale? Invite me to that party! Clay/Lexi

[Cadman-iac]

Hey Cadman-iac, you preparing for a massive garage sale? Invite me to that party! Clay/Lexi

 I'm not sure yet what I'm going to do with all this stuff. I'm at least trying to organize it and identify it so in the event of my demise, my wife can proceed with the sale. Or she can just dig a great big hole and push everything in including me!

 Rick

[Lexi]

I'm not sure yet what I'm going to do with all this stuff. I'm at least trying to organize it and identify it so in the event of my demise, my wife can proceed with the sale. Or she can just dig a great big hole and push everything in including me!

 Rick

Wow, does that sound familiar! Hope your better half never chats with mine. They might get ideas. And painful ones at that. At least with your last comment the F*%$#*& greenies will love it... (Reduce Re-use Recycle). Clay/Lexi

[Cadman-iac]

 Anyone have an idea as to what this fits?
 I'm guessing it's an early Hydramatic because of the side cover and the huge case size. It's much bigger than the 56 Hydramatic.
 
 What was the first year that the Hydramatic was used?

 And on the flathead engines, don't they have a lip on the back of the block like a partial bell housing, or am I thinking of another engine?
 If they do, then that might explain why this has such a short bell housing on it.
 
 Anybody?

[dn010]

1955 Olds, hydramatic.

[Cadman-iac]

 

1955 Olds, hydramatic.

 Dan,
 Thank you for your reply. That makes sense, as the Oldsmobile engine does have that lip or partial bell on the back of the block.
 I had forgotten where I got this transmission until you mentioned Oldsmobile.
 I got a bunch of stuff from the widow of a friend many years ago, and this was in with it. He had been into 54 Oldsmobiles.
 What I find interesting is that the dipstick has Cadillac stamped on it twice, which lead me to believe it was from a Cadillac.
 I have 3 '64 Oldsmobiles and the dipsticks on those only say Hydramatic, no other names.

 Thanks again for your help.

 Rick

[dn010]

It could be that the stick original to the transmission was lost/misplaced or damaged and replaced with one that worked from a Cad. I've found this scenario a few times working on past cars; you never know what someone else did in the past 50-80 years. What is worse with dipsticks is you then never know if the replacement has the marks in the same spot as the original!

[Lexi]

Well said Dan. See my last 2 posts (#81 & #82) on Rick's water pump enquiry in the General Discussion section. A lot can happen in 70 or 80 years! Clay/Lexi

[Cadman-iac]

  I didn't think about the dipstick being swapped, good point.

I had thought because of the weird oil pan it would be easier to identify. Did Cadillac ever have a pan like that?
And if not, because of how the tube attaches to the pan, you would think that the stick would be different.
Moot point now though. It's Oldsmobile!

Thanks, Rick

[Lexi]

I don't think about the dipstick being swapped, good point.

 Thanks, Rick

When I had my 365 engine rebuilt in 2019, the oil diptube became a huge issue as it was damaged, so I required a new tube (I had the proper dipstick). Upon checking out the engine on the bench, I was fortunate that Chip's Caddy Parts (on Ebay) replacement diptube fit like a glove. Perfect length with installation instructions. When that OEM oil dipstick goes in, it just clears the crankshaft. Very close tolerences as I remember. You got to have the proper spec'd parts to go in there. I didn't really consider the diptube until the build was half way done. Something not to neglect. I had extra parts here but went with a new replacement tube from Chip and it was dead on. Clay/Lexi

[Roger Zimmermann]

Rick, don't forget that Pontiac used the same transmission! + other brands like Hudson, Lincoln...

[dn010]

Well said Dan. See my last 2 posts (#81 & #82) on Rick's water pump enquiry in the General Discussion section. A lot can happen in 70 or 80 years! Clay/Lexi

I checked it out Clay, it was a good read. You never know what someone tried to make work on these old cars. I just looked at a 48 Chevy and found an actual metal link chain stretched tightly from the engine to the frame. I thought to myself, maybe the crossmember is weak and the chain is holding the engine up. Turns out, someone installed the chain as an attempt to make a ground strap! 

Rick, don't forget that Pontiac used the same transmission! + other brands like Hudson, Lincoln...

The others used the same 8615013 case but with different configurations (tail shaft length, bellhousing etc.). Judging by the photos, this one looks to be specific to the Olds.

[Cadman-iac]

  I'm fairly certain that it's an Oldsmobile transmission. After Dan mentioned that I remembered where I got it, and it also included 3 old Oldsmobile engines that I stashed away and covered up to protect them. I totally forgot all about having them to be honest, but when Dan jogged my memory, I went out and uncovered them to double-check the back of the engines, and sure enough, they have a "half bell housing" that matches the transmission.
 So that mystery solved.

 What I find odd is how much the pan surface sits on an angle, like Oldsmobile tilted it for clearance or something.
 Did Cadillac do that with any model year?

 Roger, yes, I know that the other GM lines used the Hydramatic. My dad had a 56 GMC with a Pontiac V8 and the Hydramatic transmission. But if memory serves, it didn't look like this one.

 Thank you all for helping me "remember" something I shouldn't have forgotten. I'm grateful for all the comments.

 Rick