Herding Goats Posted July 21 Report Share Posted July 21 Hi all, my friend's 1939 Chrysler Royal has a leak in the front of the 3-speed manual transmission. When we jacked up the back of the car to work on the rear axle grease seals, oil dripped from the mating surface of the bell housing and the front face of the transmission. With the car back on level ground the leak has stopped but we'd like to get to the bottom of it. The transmission was recently rebuilt and installed without the gasket between the bell housing and transmission. Would this be the obvious culprit of such a leak? Anything else to look for? Curious if anyone has experienced a similar problem or what that missing gasket is supposed to seal. Thanks for any ideas! Quote Link to comment Share on other sites More sharing options...
Sam Buchanan Posted July 21 Report Share Posted July 21 (edited) Use this link to find results of a Google search with many of the threads in this forum on transmission leaks: https://www.google.com/search?q=site%3A+p15-d24.com+transmission+leak&oq=site%3A+p15-d24.com+transmission+leak&gs_lcrp=EgZjaHJvbWUyBggAEEUYOTIGCAEQRRg60gEJMTUwODdqMGo0qAIAsAIB&sourceid=chrome&ie=UTF-8 Here is a thread I started about resolving a large leak on the front of my P15 transmission: https://p15-d24.com/topic/58630-major-leak-countershaft-3-speed/ It is my experience the paper gasket between trans and bellhousing will not stop drips from a transmission that isn't sealed properly. Edited July 21 by Sam Buchanan Quote Link to comment Share on other sites More sharing options...
keithb7 Posted July 22 Report Share Posted July 22 (edited) I’m not smart enough to figure out what that paper gasket between the transmission and the flywheel housing, is sealing. Is it the area where the counter balance shaft protrudes through the transmission housing? I just put some aviation black sealant in the bore before I set the countershaft in place. I guess there may not have been such a product in 1939. Edited July 22 by keithb7 Quote Link to comment Share on other sites More sharing options...
Sam Buchanan Posted July 22 Report Share Posted July 22 (edited) I don't understand the gasket, either. The gasket doesn't cover the area of the transmission where the countershaft bore is located. Plus, the gasket has a slot underneath the location of the bearing retainer (??). Beats me...... However, I have a lot of respect for the old MoPar engineers, those dudes were sharp about how to work with the technology available to them....wish I knew what they were thinking. Edited July 22 by Sam Buchanan Quote Link to comment Share on other sites More sharing options...
Sniper Posted July 22 Report Share Posted July 22 6 hours ago, Sam Buchanan said: the gasket has a slot underneath the location of the bearing retainer (??) Pretty sure it's a drain for any leakage around the input shaft retainer.. Quote Link to comment Share on other sites More sharing options...
Sam Buchanan Posted July 22 Report Share Posted July 22 (edited) 2 hours ago, Sniper said: Pretty sure it's a drain for any leakage around the input shaft retainer.. That's the same conclusion I came to and another reason why it seems to me the gasket is ineffective at stopping leaks at locations that are supposed to be sealed. Guess it's better to let the bearing retainer leak down the gasket slot instead of into the bellhousing. Of course the retainer is supposed to be sealed and draining oil back into the trans case. Now.....the gasket is staring at us on the workbench, do we install it or leave it on the bench? Edited July 22 by Sam Buchanan Quote Link to comment Share on other sites More sharing options...
soth122003 Posted July 22 Report Share Posted July 22 If I had to guess (and I do that a lot, with mixed results) I would say it was not to stop leaks, but to stop corrosion from the mated surfaces. The slot on the bottom of the gasket is for the guessed purpose of letting oil drain out to keep it from building up and getting onto or into the clutch area. The rest of the gasket IMHO is to keep moisture out of the area that if it got in there could cause rust that would stick the parts together or corrode the mating surfaces. Think about how the rear axles look when you pull the drums off. There is always rusty areas that have to be cleaned up. Joe Lee Quote Link to comment Share on other sites More sharing options...
Sam Buchanan Posted July 22 Report Share Posted July 22 (edited) That sounds reasonable to me, in that case I would install the gasket. Guess a little leakage would be the anti-corrosion system. That system is alive and well on my car! 😁 Edited July 22 by Sam Buchanan 1 Quote Link to comment Share on other sites More sharing options...
Sniper Posted July 22 Report Share Posted July 22 I dunno, later mopar transmissions that I have dealt with do not have a gasket between the trans and bell housing, Not sure why they put on in there. Also, they usually have a welch plug to seal the end of the counter shaft. Not sure if one could be fitted here. Quote Link to comment Share on other sites More sharing options...
Herding Goats Posted July 24 Author Report Share Posted July 24 Thanks for the link @Sam Buchanan. I was struggling with the search and seemed to be only pulling up posts about rear seal leaks. I read through your thread and that does seem like the place to start. Thanks everyone for your thoughts on the gasket's mystery purpose. It does not seem like that would be the cause of the leak, however we will likely put one in. Nothing to do now but pull the transmission out and have a look! Thanks for background info, will report back. Quote Link to comment Share on other sites More sharing options...
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