1950 Buick Special Dynaflow leak

[Sonomatic]

HELP!  I have a 1950 Buick Special, 248 ci straight 8 with the Dynafow.  Transmission works great, but has really started to leak, as you can see.  I suspected the front pump seal, but, from what is seen in the video, it looks more like the gasket on the front cover of the converter.  Either way, it has to come out for repair, I'll do the gasket and the front pump seal, and possibly the front pump beairing, we'll see what it looks like.  My real problem is this.

 

1.  The transmission number in the first still picture begins with an F, which, according to Hometown Buick designates it as a 1951 transmission

 

2.  As evident in the second picture, there is a witness mark of a fastener, which leads me to believe the transmission has been out at some point and, either not reinstalled as originally installed, or, this is a 1951 transmission, and, for whatever reason, bolts up slightly different than the originlal 1950 transmission.

 

3.  This theory is further evidenced by the slightly misaligned drain plug and another witness mark where a fastener was installed at one time but not now

 

4.   The 4th picture shows the other drain plug centered in its access hole.

 

5.  Paint mark on torque converter.  So far, I haven't found a corrosponding mark on the flywheel, but haven't looked that hard

 

The car runs and drives smooth, leading me to believe that engine/transmission balance isn't affected to any great degree.  I'm also not completely convinced that the torque converter wasn't installed 180 degrees out.  

 

My question is, does anyone have first hand knowledge as to whether there was a mounting difference in the torque converter to flywheel mounting of 1950 to 1951 cars?

 

6.  Engine number in 6th picture.  I believe this is a 1950 248 because it has hydraulic lifters and doesn't have the block reinforcements that the 263 has.

 

Any knowledge anyone has on this subject will be greatly appreciated.  In the mean time, I'll be preparing to remove this transmission and see what else I can discover.

 

 

 

 

[Ben Bruce aka First Born]

Engine is a 1950 from a Special, therefore a 248.

 

 Jim's Dynaflow Service

  Jim Hughes

  Perrysburg, OH

  419 874 2393

 

  Bet he can help.

 

  Ben

[DonMicheletti]

My uncle had a transmission shop back in the 1960's. He did a lot of Dynaflows.

Later converters had an "O" ring instead of the paper gasket.

I would machine a grove in the old converters to take the newer "O" ring. More reliable.

[Sonomatic]

Hey Ben!  How are you?  I think I’ve heard of that place before. Probably could help. That’s one of the things I considered. Calling them up to see if they could turn it real quick. I could just haul the trans there, wait a day, then bring it back. Would cost about $900 to ship it there and back, I could drive there for less. It’s gotta come out either way. I just can’t figure out what it is I’m seeing there. I have a parts book for 1948-1963 Dynaflow. The torque converter housing or primary converter pump, the primary converter pump cover and the gasket are the same from 1948-1951 F341. Mine is F133, so it doesn’t matter if it’s a ‘51 trans. I’m beginning to think they mated it up 180 degrees out. What I’m wondering about now is, I have 2 places on the flywheel that had fasteners at one time, but they’re empty holes now. I wonder if there’s only one fastener holding the flywheel and torque converter together. 

[Sonomatic]

Yes, I’ve heard of that modification. I suspect that that may have been one of the changes to F341. Sadly, I’m in tiny, Dover, DE that, among other things, is the only state capital in the lower 48 that has only a volunteer fire department. I suspect I’ll be going with the paper gasket. Thank you for your suggestion though. 

[kings32]

There is a shop in carlisle Pa that still works on the old Buick trans taking one up next week .Kings 32

[avgwarhawk]

https://www.dorseytransmission.com/

 

Located in Hanover MD  Ask for Jack. 

Edited February 27, 2023 by avgwarhawk (see edit history)

[Sonomatic]

I have a call into Jim's Dynaflow Service and Dorsey's Transmission.  King 32, do you have a name and number for the place you're going to in PA.?

 

In the mean time, I did some research trying to find out why there are previously used, but now unused bolt holes on my flywheel.  Here's what I found out.

 

1.  48-52 small engine Dynaflows had 24 nuts holding the torque converter together and 6 additional bolts holding the torque converter to the flywheel.  

 

2. In 1953, along with the 264 and 322 V8's, Buick introduced the Twin Turbine Dynaflow.  The big deal was that torque multiplication went from 2.25 : 1 to 2.45 : 1.  Also, even though it was the last year for the Straight 8, specifically the 263, in the Special only, Buick produced a version of the Twin Turbine for the Special.

 

3.  This Twin Turbine had 15 bolts holding the cover on the torque converter and 3 bolts holding the torque converter to the flywheel.  Guess how many bolts are in my torque converter and how many bolts are holding the torque converter to the  flywheel?

 

4.  When I first got this car, I read all these posts that talked about how lethargic and slow the Dynaflow was in these early Buicks.  I've driven in city traffic and have no problem keeping up with traffic flow.  I also discovered that my speedometer has to read about 62 mph to actually be going 50 mph.  If the car this transmission came out of had 3:36 gears, that would explain my speedometer error mathmatically.  

 

5.  There is no doubt that the torque converter in my car is not a 1948-52 Buick.  I suspect the entire transmission is from a 1953 Special.  From what I can tell from pictures, the '53 Twin Turbine torque converter is thicker.  Some how, it ends up being the same length as the 1948-52 transmission.  I'm hoping Jim's Dynaflow Service can shed some light.  This may have been a popular upgrade at one time, I just don't know.  We'll see.

[kings32]

The shop in carlisle    Lupfers Transmission 1050  Harrisburg Pike   1717 249 4903  . Great people to work with . Howard

[Sonomatic]

Thanks Kings32. I’ll give them a call too. 

[EmTee]

If the car runs smoothly without vibration now, I would definitely mark the flywheel/torque converter to ensure it goes back the way it is now.  This is more important if the trans or converter are not original to the car.  If that's the case, any factory markings may no longer be valid...

[Sonomatic]

So here's an update for my Dynaflow.  As I originally stated in my post, I was concerned that there were only 15 fasteners on the torque converter instead of the 30 that the 1948-50 transmissions had according to the service manual.  (I also have a 1948-50 Dynafow service manual, a parts manual that cover 1948-1963, and the Dynaflow Doctor Manual.)  So, on Ben's recommendation, I called Jim Hughes in Perrysburg, OH.  I described that I had a '50 Buick with a Dynaflow that was leaking severly, and that when I pulled the covers to see where the leak was coming from, I found only 15 bolts on the torque converter.  His response was, "Excellent!". He told me that the transmission was a 1951 with the updated converter that has the "o" ring instead of the troublesome gasket found in the 1st generation converter.  He said a lot of people replaced their 1st gen transmissions with the 51-52 transmissions to get away from the gasket. (DonMicheletti posted that his uncle said that it was common to machine the torque converters for the 'o' ring to replace the gasket).  Jim told me that, because I had that transmission, my leak was most likely from the front pump seal because the "o" ring converters never leaked.  I asked him how much to reseal one of these Dynaflows and he said $1500, but, he wouldn't be able to get to it until June.  He's semi retired, has some transmissions lined up right now, one all the way from Austalia.  He also uses ABF for shipment, $300 each way, and he arranges the shipping.  Jim was lots of help, set my mind at ease, I actually thought I had a cobbled together mess, although it works excellent.  But, I don't want to wait until June.  Next I called Lupfers Transmission.  I asked if they worked on Dynaflows, and I was told that they did, but, didn't like to.  Also, wouldn't give an estimate without seeing the transmission.  Last, I called and spoke to Jack, the owner of Dorsey's transmissions.  Seemed quite experienced, but suprisingly, said they don't do bench work.  They want the car so they can do all of the work, too many instances in the past with people bring transmissions for rebuild, then the owner reinstalling without flushing lines, letting torque converters slip part way out and then breakiing the pump during installation.  He said they only do a couple of Dynaflows a year so he needed to call around to see if parts were available and how much.  I was also concerned that the new style converter wasn't used until serial number F341, this is reflected in the parts book, but he said that lots of times, they did whatever they had to do and used whatever was available.  So, I'm waiting on an estimate from Jack, but, I think I'll be doing this myself.  Oh, EmTee, yes, I agree, I'll be marking this flywheel and converter so they go back together as assembled now.  Thank you everyone.

[Century Eight]

Herb, Check out Last Chance Garage in Unionville PA fairly close to Delaware.   You can read about it on Google.  He works on old stuff, all the way back to the teens.  I have met him at the Hagley meet but I have never used him.  His name is Lou Mandich.  I would check him out, I think he has worked on some dynaflows, but you would have to ask..  

 

I like the sound of your guy in Perrysburg but it’s a long way.

 

Phil

[Sonomatic]

Thanks Phil, I'll give them a call.