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1950 Buick Dynaflow Transmission Removal, Repair, Reinstall and Tools Required


Sonomatic

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For those of you whom will use this for information, look under the Technical section to discover how I wound up at this point, removing my Dynaflow.

 

The second step in removing the Dynaflow from a Straight 8 Buick is supporting the rear of the engine while the transmission is removed.  What little the 1950 service manual shows, it does show this locally fabricated tool for the purpose of supporting the rear of the engine.  It's entirely possible to use a jack, jack stand, stack of would, but, this tool allows you to roll around freely under the car without a jack or other such thing in the way.

 

1.  Drawing and dimensions for tool.  Note that Buick specifies hardwood.  I assume that this is because this engine weighs somewhere in the neighborhood of 800 pounds.  

 

2.  Because of the hardwood requirement, I instead bought a piece of 2X3 steel square tubing.  The drawing specified 29'', because I didn't know what would be used to cut the tubing, I ordered it 30" long to allow for dressing the ends.  In my case, that was unnecessay as the cut was precision made.  The extra inch also seems to not interfere with anything.

 

3.  The drawing shows a "J" hook.  In later publications in transmission removal, the use of this tool is discouraged because brake lines were being crushed with this tool.  The "J" hook locates behind the master cylinder on the drivers side.  Because of all of this, I bent an "L" hook and left enough length to allow a nut/washer combination to be screwed on the the end of the "L" to keep it from slipping off of the frame.  I also found that I had to grind the  short part of the "L", frame side, threads flat, to allow the short side of the "L" to slide under the brake line.  Make sure you decipher the previous line, however convuluted it is, it is critical to the success of the "L" bracket.  The drawing specifies 5/8 rod, with the last 5" threaded.  I was only able to source 5/8 all thread.  If I had only been able to find 1/2", I think I would have used that.  CAUTION!.  When you heat your all thread to form the "L", heat the inside of the bend only to cherry.  Heating the outside will cause it to crack and possibly break off.  Don't forget that this engine is heavy, and even though the engine mounts are holding the front, this tool is slill supporting 400 lbs.  

 

4.  Close up of the nut and washer welded together, yeah, the weld is ugly, but objective is to show how nicely the nut/washer secures the end of the "L"  

 

5. This is the engine support installed.  it isn't tight up against  the oil pan because I don't want to scratch my pretty paint, and second, as you can see, my "L" hook long ends need to be shortened to the specified 11".  Let me add, my best freind, Roger Kruser, happened to have a 5/8 drill bit and we drilled two, very precise holes.  The 5/8 all thread slid through like socks on a chicken.  I found out during mounting of the tool, that precision is too much of a good thing and the support binds on the all thread, not because of the thread, as you would expect, but because the support has to be exactly 90 degrees to the "L" hooks to slide up and down.  I'll be hogging the holes out a bit to aid installation.  The large washer I'm using with the nut will keep any trouble at bay.  Once cut off, I plan to grind/file the end of the "L" hooks facing down, round, so if it run into them, well, you get the idea.

 

6.  This is a shot from the back side of the frame where the master cylinder is mounted, and you can see how the nut/washer contraption positively locates the "L" hook.

 

The next think I will show is how I got the 20" frame to floor clearance so that the transmissio will slide out from under the car.

Drawing.jpg

My engine support.jpg

L Hook.jpg

Close up.jpg

Installed.jpg

Over the frame.jpg

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Another tool from the service manual and/or the Dynaflow manual.  This is for using with a fish scale to set/check torque ball tension.  The first drawing is for early cars to 1950 or maybe early 1951.  The second drawing is from a service bulletin book for '51 & '52, where I also found the information about why my torque converter had 15 bolts instead of the 30 bolts shown in the service manual.  The last picture is the tool, made from three layers of maple hard wood and coated with epoxy to prevent oil staing, by my best friend, Roger Kruzer.  Even if I never use it, I'm going to have to make a peg board wall for my Dynaflow special tools, and this will be the center piece.

Drawing.jpg

'51 later torque ball tool.jpg

Torque Ball Tool 1.jpg

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1.  Car rased for transmission removal.  

 

2.  Close up of cribbing for front wheel

 

3. Cribbing on frame on in front of rear wheel.  Rear has to be free to move back to disengage torque tube from back of transmission so cribbing was put under frame

 

4.  Service manual recommends a minimum of 20" to allow transmission to be slid from under car.  I have 28", hoping this will allow transmissin on transmission jack to roll out from under car.

Front on cribbing.jpg

LF on cribbing.jpg

LR on frame.jpg

28 to frame.jpg

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You could also make up 2, 3" guide pins to align torque tube when connection made, take a bolt cut the hex head off and use a air cutoff tool and cut a slot so you could us a flat tip screw driver to remove guide pin when completed.

 

Bob

 

EDIT: Also view @Mudbone 5 part series on rebuilding his Dynaflow for his 1955 Buick, that will give you some clarification to help you with your reseal.

Edited by NailheadBob
update (see edit history)
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This was as of Friday afternoon, just now posting, I was wooped, and Saturday, drove to a swap meet, Sugarloaf Mtn. Westminster, MD.  Raining, cold, lots of stuff, but nothing for '50 Buicks.  I'm looking for rear bumper, and backup light housings with better chrome than I have.  Anyway, on with the story!

 

Removing this transmission was not really any harder than any other rear wheel drive transmission.  It is, howerver, full of things required that you won't see on a newer car.

 

1.  Panhard rod removed, (positions rear side to side).  Sorry, no photos, not hard to do, but requires some studying to figure out what should come off to let rod come off.  Soon as rear dropped down, shock links came off of the pins.  1st picture is pins being removed with puller.

 

2.  Rear slid back almost far enough, spines revealed but not clear.

 

3.  Emergency brake cable disconnected.  I measured the amount of threads showing before disconnecting as it worked perfectly before.

 

4.  Staps on rear.  Worked, but barely adequate.  NailheadBob, your tool would have worked much better and would have avoided a situation noted further in the pictures

 

5.  Manual states at leas 20" to the frame, I have 28".  Oldtank warned me that there would be a lot of scooting around under the car.  I could actually craw around on my hand and knees.  Had to lay on a creeper to be able to reach most things.  Lots of room, not one head bump.  Take the time to get the car high enough, SAFELY.  Cribbing is best, period.  Lots of time involved, but car won't wind up on top of you.

 

6.  This is all the farther the trans had to come back to come out. I deviated from the manual and took the crossmember out.  Trans came back maybe 1 1/2' to clear torque converter pilot into crank, and then straight down.  Note:  Manual doesn't mention starter removal, in fact, does mention using starter to rotate flywheel to access torque convert bolts to flex plate.  I took the starter off because the manual mentions "knocking a pin out with an offset wrench".  I removed a nut and a bolt above the starter, but still couldn't determine what they were talking about.  Once transmission was out, I discovered that the lowest bolt on the passenger side of the bellhousing is, in fact, a locator pin.  Stayed in bell housing during removal.  Note:  No prying required to seperate bell housing from engine.  If you are having to pry, something is wrong, figure out what it is, when all of the bolts are removed from bell housing, transmission seperates from engine without assistance.  

 

7.  Rear comes back fairly easy, only rear resistance is the driveshaft tube on the X member it goes through, just behind the transmission.  Check things often.  I accidently discoverved the brake line stretched to the limit while I was rolling forward to check the gap in the splines at the back of the transmission.

 

8.  She's out!  Hats off to all of you that do videos.  I got wrapped up in the removal and didn't take any pictures of the transmission on the trans jack coming down.  As you can see, she rolled right out the front.  First thing I discovered, torque converter moves forwards and back 3/16 of and inch.  No idea why yet.  Plan to clean exterior thoroughly before accessing inside.  Trans worked perfectly, but leaked heavily out of front pump seal.  I plan to call Jim Hughs Monday and see what he thinks I should be looking for.  

 

9.  Casting number on the case.  As I said earlier, the number stamped underneath on the aluminium on the underside is F133, meaning that this is an early '51 transmission.  However, it has a 15 bolt torque converter, designating it as a late '51 or '52 trans, ('53 saw the twin turbine come on the scene).  Also, this car was undercoated, not one rusted or stuck screw, even brake lines came apart with almost no coaxing.  So how and when did this transmission get put in hear?  Still a mystery.

 

To be continued//////

 

 

shock link pin.jpg

Driveshaft splines.jpg

Emerg brake cable.jpg

straps on rear.jpg

view under car.jpg

Driveshaft clear.jpg

Brake line.jpg

She's out.jpg

Casting number.jpg

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Does anyone know what color these transmissions were painted by Buick.  I might find some color on the tailshaft after cleaning, but I doubt it.  If anyone knows, that would be very helpfull

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Yesterday, the owner of the airport where I'm working on my Buick in one of the hangars, loaned me his forklift and steam cleaner.  Jet is not as powerfull as a pressure washer, 1000 psi vs 15-2000 psi.  Did a good job on grease and oil, did nothing on udercoating.  You can see some on the upper pan rail in the shot of transmission hanging from forklift.  Talked with Jim Hughs in Ohio, he says, pull the torque converter, change front pump seal put 'er back together and let 'er eat.  Plan today is to drain pan and torque converter, pull pan while still on the hoist, see what's in the pan, clean it out and  put that back on, then pull the torque converter and see what I've got.  Does anyone know what color these transmissions were from the factory?

Steam Cleaner.jpg

Hanging from forklift.jpg

Operating table.jpg

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Make sure you mark front cover and front pump (the part front cover attaches to) before you take it apart 

 

I am jealous of your space working in hanger

 

I don’t know the correct color of your transmission 

 

Bob

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Do we think they were even painted?  Could have been bare, or black or turquoise.  I have never seen a color on my tranny.  I am sure you have asked your tranny guy in Ohio.  Next time i am under my car, i will take a mirror and light to check.

Phil

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When I was steam cleaning it, I saw no paint on any of the cast iron, but the aluminum for the valve body was black and there may have been black paint on the pan.  I suppose it doesn't really matter, but I have that nice oil pan under there so....

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Pulled the pan last night.  Nothing more than what you might see in a modern transmission pan.  Screen appears to be about 50% clogged.  I'll take car of that, clean the pan and reinstall.  Then, I'll sit her on the table and pull the torque converter and see what's what.

Pan removed.jpg

Trans pickup.jpg

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24 minutes ago, Sonomatic said:

Nothing more than what you might see in a modern transmission pan. 

Well that looks like more than I would want to see.  The torque converter has to be disassembled to replace the seals, check it carefully, since it would be the source of all that metal in the pan and screen.

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When converter off, also inspect closely, input shaft bearing/bushing for wear.

 

When transmission pan back on and sitting on bench, @Mudbone in one of his video's made a square tube oil pan protection bracket so transmission would not rest on bottom of oil pan on bench, great idea by Mudbone.

 

Bob

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Yes, I saw that.  Nice Idea.  Right now, mine is hanging from the engine crane and that it working well.  I might build one of those at some point.  Today was the day, pulled converter off, and there it is, the pump seal.  I don't really see anything wrong with it, it seams pliable, no splits.  The surface it rides on seems good as well.  Pump seal and torque converter "O" ring showed up today,along with the trans mount and thrust mount.  I won't be able to begin assembly and reinstall until Monday.  Hope to have it driving in a weed or so to see what I have.

Converter parts.jpg

Pump seal.jpg

Seal surface.jpg

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Thanks NailheadBob.  When I was researching tearing into this Dynaflow, I came across a sight that uses parts of the torque converter to make banjos.  The case and bell housing are very rough sand castings.  So far, I am really enjoying this adventure.  Looking at the pump seal, I couldn't really see anything wrong with it.  After looking at the new seal, I believe that the lip of the old seal is just worn away to the point that it doesn't seal anymore.  The new seal also has a spring behind the lip.  Also, you cant tell from the picture, but I wiped the seal surface clean, there was a shiny spot where it was riding, but I held one of those pocket rulers against the surface and shone a light from underneath and could see no light slipping through.  I'm gonna put back together and see what I've got.

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I had my '60 Electra Dynaflow rebuilt by a local shop two years ago. They sourced the parts through FATSCO. Their SOP was to order the parts after disassembly and inspection. To save time and knowing everything was 60 years old I asked if I could order everything available in advance. They were fine with that.

 

FATSCO has a bushing set: https://www.fatsco.net/online-store/1948-1954-Dynaflow-Bushing-Kit-p447113129

 

I ordered that, the major rebuild kit, and a torque ball seal. All were in the car when I dropped it off. Actually it was the week of Good Friday on Monday. I got it back the next Tuesday. That included it setting over cardboard one extra day to verify a drip was from the old leak.

 

For the 80 bucks the bushings eliminated a judgement call. I have that on another car and it whines.

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Latest update:  Monday, April 3, 2023, removed the old front pump seal, drove in the new seal with a length of 2" PVC pipe.  Slid the converter parts on, no issues, got ready to put the front cover on and found out at 6 pm that the "O" ring seal was too big.  I got the seal kit from Cars Transmission Solutions in California.  Called them up, (still open due to the time difference), told them I had a late '51 transmission. The guy said, "Yeah, we run into this once and a while, I have the correct one on the shelf, you,ll have it Wednesday.).  The kit was listed for '51-'63.  Just be ware, if you have a '51-'52 with the "O" ring, it's smaller by 1" in diameter than the '53-'63 "O" rings.  

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This is what the leak on my Dynaflow looked before I removed it.  I could drive about 5 miles, then would check and add fluid to get back home.  I haven't posted in a few days because Ipm dealing with the filter screen.  When I have the solution, I'll bring this thread up to date.  

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Honestly, What I saw when I pulled the torque converter and front pump seal didn't show me anything that would cause that.  Once I have the filter screen issue resolved, I'm gonna put her back in and see what I've got.  It'll either be fixed or it won"t.  I'm anxious to go to car gatherings, but, I like wrenching on this old gal pretty good, to.  Good to hear from you Ben.

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I don’t mean to rain on your parade BUT from what you described on what you found with your seal, the video shows something a lot worse

 

did you check wear on input shaft bushing? That might explain your leak

 

Bob

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The only check I did on the front bushing was to grab the 4 bolts that I rotated to the top position on the torque converter and loop my thumbls over the top of the bell housing and lift up and down.  I felt no play whatsoever.  Unscientific, I know, but, if the bushing was worn enough for that leak, I should have been able to feel it.  Also, in discussing it with Jim Hughes  @ Jim's Dynaflow Service in Ohio, he told me that the torque convert is bathed in oil from the pump and almost never wears.  I will find out soon enough.  If it leakes, it will take me half the time to take it next time.  There are those that would blow this thing apart, replace everything that can be replaced, and put it back together and have a brand new transmission.....or not!  Mudbone's post is the best tutorial I've seen on rebuilding a Dynaflow, and, during his testing, after the trans was back toghether, he found a gasket that was wrong, which he also used the wrong gasket which didn't show up until his testing.  The best thing about Mudbone's rebuild was the testing that was done before installing the transmission.  Anyway, I am averse to blowing this car all apart, having it scattered all over and then something happens where I'm not able to put it back together, nor am I around to tell anyone where everything is.  I see cars for sale like this all the time, someone blows the car apart, then, for whatever reason, it doesn't get put back together, the wife is stuck with it, and no one wants to tackle the job of putting it back together.  I don't want to be in that position.  I have used the approach I am using in the past, get it running, which, while doing so, you learn alot about the vehicle, what it needs and what it doesn't, and once you have it mechanically sound, you go back and address the issues with a plan.  That's my plan.  Plus, If I have to take this trans out again, It's not that big of a deal.  If it works, my plan is to find another Dynaflow like I have and do the complete overhaul, bearings and all, and put that in my car or another.  I do agree that that leak looks serious, it leaked when I got it, but not like that.  I'm also not going to fault you for raining on my parade, the chances are just as good that I do have another problem.  The main thing that motivates me to go ahead with my path is that ther was nothing on the bearing surface of the torque convert to make me thing the bearing was worn terribly.  We will know soon enough.  

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It sounds like you have the right attitude!  ;)  How much lateral play is there on the input shaft?  Were the converter cover bolts tight?  What's the issue with the filter screen?

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I'm with you.  If a seal is leaking replace the seal.  An entire rebuild is not required for a leaking seal.  Specifically if the transmission was working correctly with the leak.  Any-who,  the torque convertor has a very large O ring seal in the front correct?  If so, is this possibly the leak?  

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This is the seal that is believed to be causing the  leak.  There is a gasket behind the front pump, but highly unlikely that it is leaking.  The converter bolts were tight, this is a late '51 or '52 Dynaflow, the "fix" for the leaking converter cover gasket.  This converter uses the "O" ring, very reliable.  It is theoretically possible for the converter cover, front pump to converter garlock seal, or the pump to front of transmission gasket to be leaking.  The most likely is the front pump to converter garlock seal in the picture.  From what I understand, these usually leak due to the seal becoming old, sometimes, bearing wear on the bearing that supports the converter can cause enough play to cause thes to leak, as stated previously by NailheadBob, but that too is not true in most cases.  There is no way that I have found to tell what's leaking with the trans installed and running, I wasn't able to see any of the seals.  My best clue was the leak in the video.  If it were the converter cover, it would have sprayed all around while it was spinning.  What I had was a leak that was runnig out of the bottom of the bell housing, just past the centerline, in the direction of rotation.  That makes me thing the garlock seal.  If it were the gasket between the front pump and the front of the transmission, I would expect it to run almost exactly down the center of the trans and also, some eveidence of the leak between the bell housing and the front of the transmission on the outside.  All of this is conjecture on my part, because I couldn't actually see where the leak was exiting the transmission, so, I'm rolling the dice to an extent.  As for the oil filter screen, the uniformity of mesh was disturbed, allowing gaps in the screen, which would allow bigger chunks of whatever into the trans, and more importantly, the pump, than I was willing to take a chance on.  The pump is $800 on e-bay.  Also, this screen sits about an 1/8" off of the bottom of the trans oil pan, so, I was worried, and took it back apart and I'm waiting on one from Jim Hughes.  I really appreciate the input from you all.  It's always a good thing to have a second set of eyes looking at what you're doing.  Thanks to all of you.  I also hope this helps someone out, like Mudbone's post helped me.  Also, had a lot of good info from Old_Tank.  He was my inpiration to pull it out myself.  

Pump seal.jpg

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