1947 transmission leak

[Paul Tesone]

I am presently restoring a 1947 convertable with a hydromatic transmission.Last summer, I started driving it after 10 years of sitting in the garage. I didn't notice any leaks.During the early phase of the restoration, it was driven or at least started and moved every week or so. Again, no leaks during that time.Now that it has been sitting for a while in the shop, it has developed a leak where the shift linkage goes into the transmission ( as I understand the explation from my restorer ). This sounds exactly like the problem fellow member Tony Zappone was having - see his post on 4/16/08. My restorer has proven to be very knowledgeable and I know absolutely nothing about transmissions other than I have to put the car in gear to make it move. Having said that , I would like to try and explain my restorer's explanation and seek comments from members who have had a similar problem or who can comment on the explanation I have been given. He feels that when sitting idle, transmission fluid is draining down from the torque converter and overfilling the transmission( when taking a measurement of fluid level, it is very high). The fluid level reaches the level of the shift linkage and leaks out. The felt seal is normally not subjected to immersion nor meant to be immersed in transmission fluid. It is designed to seal the linkage and prevent leakage from splashes of fluid in the transmission. He feels that when starting or driving the car , transmission fluid is pumped back into the torque converter thereby lowering the fluid level below the seal to its normal level and the leak stops. SO , my questions to the members are - does this explation sound logical ? If so, is there some sort of check valve between the torque converter and the transmission which is faulty and can be replaced? Will draing the torque converter as described above eventually damage it even if I wait for it to refill before putting the car in gear and driving. Thanks to all who have had the patience to read this lengthy message and to those who may offer some advice. Paul Tesone - #6876

[Glen]

Paul, one correction, there is no torque converter in a 1947 Hyda-Matic.  What looks like the torque converter is actually the fluid coupling also known as a torus member. 

The explanation given to by you the mechanic is plausible.  I’m not sure where the fluid level is in relation to the shaft.  But I don’t believe the cars did that when new.  So there is a problem with the shaft seal and with the seals that hold the fluid in the torus member. 

I don’t think there is any harm in running the transmission this way except for the leaking on the garage floor. 

Glen

[Paul Tesone]

Thanks Glen - I'll pass your info on to my mechanic. As much as I hate to have the transmission or torus member messed with, I think it's unrealistic to think that I'll start the car faithfully every week or so during the winter. As you mentioned , that will result in a mess in the garage. Next step is to find a good transmission person in the Boston area if my mechanic doesn't want to tackle the job. Thanks again, I appreciate your imput. Paul Tesone  #6876

[Robert Schuman]

Paul,
Are you sure the transmission isn't just overfilled? To check fluid level, the transmission should be warmed up(at least 5 miles of driving), parked on a level surface with the handbrake on(or wheels blocked to prevent movement) and the transmission in Drive with the engine idling.
Bob Schuman

[Paul Tesone]

Hi Robert - thanks for your interest and suggestion. I'll call the shop and check with my mechanic , but I don't think that's the issue. He tells me the leak didn't start until he stopped driving the car, therefore leading him to believe the excess fluid was draining into the transmission  from the torus member ( I called it a torque converter in my post ).  I'm assuming he checked the fluid level at some point while driving the car, but I'm not absolutely certain of that. All I know is that when he did check the level while the car was leaking, it was very high. I'll find out on Monday. Thanks again. I really do appreciate your help. Paul T. #6876

[35-709]

I had basically the same problem with a used 1985 Jaguar XJ6 ---- don't ask, I bought it cheap at my wife's urging and she loved the car.  NEVER hurts to score a few extra points with the little woman!  Super nice looking car and she only drove it on special occasions so it sat a lot (saved a lot on repairs that way --- I hung a sign on my 3 tier roll around tool chest that said "Jaguar tool kit").  Borg-Warner automatic  that would apparently "leak down" internally when sitting for longish periods and would then proceed to leak on the garage floor.  Pulling the dipstick without the engine running would show it WAY over full.  Running it for a few miles and then checking it again properly with the engine running would show the fluid level right back at full where it belonged or maybe slightly below because of the leakage.  Running the car more frequently solved the leaking problem, but I was always afraid of that car mechanically and what it would cost to fix.  Maybe if I understood it better I would have felt more at ease ---- naaah.  Finally convinced her to let me sell it and buy a '60 Caddy coupe.  Phew!
 

[Paul Tesone]

Thanks for the reply Geoff - sounds like what's happening to my car. But since I'm not about to sell it and I don't want the garage floor messed up with transmission fluid, I'm forced to fix it. Thanks again for your response. By the way , I too am a former Jaguar owner ( 1963 XKE ). Great car when it worked - weather couldn't be too hot, too cold, too wet, etc.  I think we're better off with caddys. Paul T #6876

[35-709]

Don't know that there is really anything wrong with the car, Paul, might just be what happens when the car sits for extended periods.  I have a large (about 3' x 2'), shallow (1 inch or so), drip pan that served me well for the Jaguar and continues to be handy for other situations.  But either way, good luck with the car.

[TonyZappone #2624]

Don't know that there is really anything wrong with the car, Paul, might just be what happens when the car sits for extended periods.  I have a large (about 3' x 2'), shallow (1 inch or so), drip pan that served me well for the Jaguar and continues to be handy for other situations.  But either way, good luck with the car.

I have ordered the seal kit from Northwest Transmission, per Bill Ingler's suggestion.  However, to confirm the supposition from many of the above comments, the leakage is worse when the car sits for long periods.  The 47 stays in Florida, so when I come back after six months, or to visit after a couple of months, the floor is covered with fluid.  Bingo.  TZ 2624

[Paul Tesone]

Hi Tony - Glad you had a chance to read my post and the comments that followed. Seems like we have the same problem. I'll pass along the Northwest Transmission tip to my mechanic and let you know if he comes across anything helpful . Thanks for responding. Paul Tesone #6876

[jaxops]

Check out the torque on your transmission tail shaft.  My 56 had to have it re-tightened after I had a pan full of transmission fluid.  They tend to loosen up if not properly tightened the first time.

[Paul Tesone]

Thanks for the suggestion Mark. I'll pass it along to my mechanic. Paul Tesone #6876