1950 Hydramatic Transmission Tail Shaft Gasket

[CadillacGlasses]

Hey Guys,

I'm struggling with getting the tailshaft gasket/seal on this '50 transmission on my conv. Is there some special trick to this? The X frame makes it impossible to get leverage with the pick-axe style puller I got. Also.. its hard to tell but the gasket I'm trying to pull off looks different than the one I'm putting on. Any thoughts?

I'm also curious if its easy to tell whether or not I need to replace the bushing. The inner shaft flexed a little when I tried to claw at the inside of the gasket.

Any thoughts greatly appreciated
Thanks!

[The Tassie Devil(le)]

I have heard of people installing self-tapping screws into the tin face, that is at right-angles to the shaft, and using long enough screws so that the head protrudes past the end of the shaft, and then with a slide hammer, carefully try and tap each screw head outwards, without stripping the thread.

Might take a few screw attempts, but worth a try.   Just don't go too deep with the points of the screws, as you don't want to touch the internal bushing.

Plus, you could do what I did and construct a fitting to attach to the Slide Hammer, out of a longish bolt, grinding it (the head) in such a way that the overall hook part is a similar thickness as the yoke, as in the left side of the first picture, or the top one in the second picture.

Sometimes you just have to be creative.

Bruce.

[Caddy Wizard]

You are not going to want to hear this, but I have tried and tried with pullers and slide hammers over the years with no success.  Without removing the tail shaft housing from the case of the transmission, the only way I have found of removing the old seal is to take a small chisel or punch and drive a portion of the seal body radially inwardly away from the tail shaft housing bore.  Once you have enough of the seal moved away from the housing, you can remove it with a slide hammer.


Essentially, you have to cut the seal out with a chisel.  Not for the faint of heart.

[fishnjim]

Proper terminology would be a shaft "seal" not a "gasket".  Gasket goes between two surfaces - usually flat.   Seals work on rotating assemblies.   
Take it to a trans shop, if need help.   No sense being frustrated and mess something up permanent.
They go in a lot easier than they come out, but not impossible.  This is one of those things you have to plan for before you start a job.   Proepr tools, porper procedure, know how, etc.  Check what the shop manual has to say about how to change, should be listed on or off the car.   Diving in is for swimmers.
As far as the sleeve/bushing, usually check the run out, but visual inspection/measurement may work if you remove the shaft.   
As far as what it looks like, the critical dimension are the shaft size, the outer diameter, and the thickness.   I doubt you'll find an exact OEM replacement these days but maybe just a difference of brands.   
If the tailshaft is worn/scored, it might continue to leak and needs replaced or restored.

[Caddy Wizard]

I have done this job with the transmission in the car many times and have yet to find any tool that will make it even remotely reasonable -- and I have LOTS of tools/pullers/slide hammers/etc.  It is a horrible job -- my least favorite on an old Cadillac.

The seal does go in smoothly, but you will need a big sleeve or socket or pipe having an outer diameter just slightly smaller than the bore of the tail shaft housing to drive it in with.  I made a wooden one with a long handle that is especially useful for this particular job.

The yoke on the front of the driveshaft should be cleaned up with some very fine sandpaper (like 800x or higher) to polish out any little grooves, ridges, or imperfections and provide a smooth, slick surface for the seal. 

Speaking of the seal, they are readily available from FATSCO in NJ.

[Joe G 12138]

There is a Kent Moore "J" tool for this. It attaches to a Slide Hammer. I've got one or two, but don't know the number offhand. I'll check in the garage tonight.  Joe Gibeault.   

[CadillacGlasses]

Oh interesting, thanks for the guidance everyone!

Thanks for the clarification fishnjim - seal vs gasket, and I agree that this is something that will require planning!

Bruce mentions a good point, the face of the seal seems to be metal, at least from what I am seeing on my car. To Art's idea of chiseling - can it be driven into or around the tin face?

I also finally found the area in the shop manual that shows this process, which is to use a special slide hammer of sorts (probably with a unique fitting on the end called Oil Seal Remover Collet No. J-2623)

That Kent Moore J tool, does it look something like this? I did some google searching and found this on ebay. It seems like it would make sense bc of the hook-style tools Bruce shared.

Thanks again for all the input!

[Joe G 12138]

I got out to the garage tonight. Here's a picture of the Kent-Moore J-2623; which is officially supposed to be used with the KM J-2619 slide hammer. This particular one has an adapter on it to use the Joe Gibeault slide hammer. It works well for removal in the car. It's listed use is all AMC, Cadillac, and Pontiac Hydramatics. I'll post a picture of a seal installer for hydramatics too if you are wondering what they look like.

[Joe G 12138]

An alternate "ace in the hole solution" KM tool that's handy to have around in case you REALLY bugger up the old seal is the J-5946 (listed for 55-56 Olds hydramatic) or the similar J-6136 (listed for '54 Olds service replacement). I couldn't find the real thing: I've still not fully unpacked and organized since my move to Georgia. But here's a picture so you can get the concept if you have to improvise. It uses  radically tapered sharp edged pipe thread, and a slide hammer.

[wrench]

I use a drip pan to solve my leaking Hydramatic seals...

Although, if I was going after one of these with or without the special tool, I would try to use 'freeze spray' on it. On assembly, I usually put the replacement seal in the freezer for a while before I install it. And maybe use a heat gun on the bore that it goes into.

https://en.m.wikipedia.org/wiki/Freeze_spray

" Freeze sprays are also used to contract metal for assembly or disassembly of interference fit parts."

In the absence of the special tool for similar dynamic seals, I have used Bruce's method of using screws tapped into the metal part and puller. Not for the faint of heart. More like mother of invention...

[Caddy Wizard]

I got out to the garage tonight. Here's a picture of the Kent-Moore J-2623; which is officially supposed to be used with the KM J-2619 slide hammer. This particular one has an adapter on it to use the Joe Gibeault slide hammer. It works well for removal in the car. It's listed use is all AMC, Cadillac, and Pontiac Hydramatics. I'll post a picture of a seal installer for hydramatics too if you are wondering what they look like.

That one should work to remove the seal.  SHOULD...

[CadillacGlasses]

Wow thank you Joe for digging those out, I've located some on ebay and am considering grabbing one..

Today I tried a variation of the chiseling theme, after finding out my drill driver wouldn't fit into the X frame (I was after the screw idea at first). I made some progress getting through the metal face, but then realized the whole thing is metal, and decided to regroup and try again later.

I'm tempted to continue destroying the piece with the dremel-like drill I found, but I also think there's a point where I need to go buy a slide hammer.

This whole project is very much "first car project in my garage" if you can't tell

It seems like the physics of all of this is to pull from the inside, with either a hook like Bruce's, or a slide hammer fitment like the Kent-Moore piece that has a claw all around. If its possible to keep crushing/tearing/drilling it, I'm up for the challenge, just worried I'll mess something up.

[The Tassie Devil(le)]

The biggest thing to avoid is getting crud, drillings, or rubbish from going deeper into the abyss.   Get stuff in there, and you probably will be having to take the housing off to clean it out.

My puller method seems to be about the cleanest.

Bruce.

[CadillacGlasses]

Crud beware.. Good point Bruce!

[Bob Kielar]

I had a pesky transmission tailstock leak and took three tries to get it to seal. As Art mentioned it is a real pain to get out. I got the first two seals from a discount vendor but they leaked. So this is what I did. Purchased a seal from Fatsco transmission. Fortunately a fellow CLC member gave me the dimensions for the Kent tool used to remove the seal. My son is a teacher at a tech school so they asked a student if he would like to make it as a project for a grade. You insert the tool and spread it with the 1/4-20 bolt then put a slide hammer in the back and pop the seal out. Instead of over a hour to get seal out it takes less then 20 minutes. I used a piece of schedule 80 gray plastic pipe with a pipe cap on one end so you can tap the new seal in. Then I used permatex transmission seal. It takes 24 hours to cure with no fluid on it. Since the tailstock seems to always seep fluid I jacked the Cadillac so the front was lower then the rear which kept the fluid off the seal and left the permatex to cure. I have not had a leak for over five years. If you need to borrow the tool pm me.

Keep Cruzin,

Bob Kielar

[wheikkila]

That is a very nice tool. Something that will come in handy.
Thanks Wayne

[CadillacGlasses]

A little update - I called over a mechanic friend of mine who had a scissor like puller that worked the same way as these Kent Moore tools. He was able to get it out, but after it all was put back together the shaft started leaking again. I'm suspecting either the seal is a dud (I should have gotten a Fastco brand seal like Art mentioned) or the tiny crack we found in the housing is the problem.

Either way, I'm putting a pan under it for now while it goes through body and paint. Once the car is one piece again I'll resume my adventures. Thanks for all the awesome help!

[The Tassie Devil(le)]

Having any sort of crack in the housing doesn't fare well for oil retention.

Bruce.

[wheikkila]

A crack is never good. I guess the question is did the new seal change it at all?
Thanks Wayne

[savemy67]

Hello Mike,

Your post doesn't indicate the location of the crack.  For the crack to be responsible for the leak, it has to be forward of the seal, and on the underside (somewhere in the 3 o'clock to 9 o'clock position) of the seal counter-bore, or in the extension housing forward of the seal counter-bore.

While it is possible the seal is a dud, the crack should probably be your first route of investigation when you resume this task.

Keep in mind that the seal is designed for components that are concentric.  The output shaft of the Hydra-Matic uses a ball-bearing and a bushing in the extension housing to maintain concentricity of the shaft.  A good seal also depends on the condition of the driveshaft yoke and universal joints.  A combination of wear amongst these components might result in a leak at the seal.  If you can move the output shaft left/right and or up/down while it is in the extension housing, you may need to check the bushing or bearing.

Respectfully submitted,

Christopher Winter