Transmission Pan Leaking

Kisner · 03-31-2001, 02:59 PM

I've been trying for 6 months to stop my transmission pan from leaking. Checked the entire transmission to ensure it wasn't leaking from anywhere else. It only leaks from one corner of the pan. I replaced the gasket and bought a new pan but it won't stop leaking. Is it possible I have a pit, divet, or hairline crack in the bottom of the transmission case? Any words of wisdom would be appreciated.

Gearhead999 · 03-31-2001, 05:42 PM

If the dipstick tube goes in the case, and not the pan. It probably is the "O" ring on the tube or the tube is bent. When it goes in the case it is the right front corner. Is that where your leak is?? Another leak could be the lock nut that holds the band adjustment. They have a rubber seal that usually can't be reused. The seal is built on the nut and you have to just replace the nut. Sometimes the fluid will come through the pan bolt threads. Put alittle sealer on the pan bolts at the wet area.

The likely hood of a hairline crack is remote. I would check what I said and if it isn't one of them. Clean everything with carb/brake cleaner REAL good. Get car in air and really eye ball it.

Kisner · 03-31-2001, 11:32 PM

I've already checked everything you mentioned, to include every square inch of the transmission. It's only leaking where the pan meets the bottom of the transmission on the left-hand side (driver's side) rear corner. About ready to throw in the towel and take it to a transmission specialist. The original pan was extremely warped - maybe the new one was warped there also - guess I should have thoroughly checked it with a straight edge before I installed it.

Gearhead999 · 04-01-2001, 10:02 AM

You also checked where the tailhousing bolts on to the main body of the transmission?? It is an easy gasket to change. Have seen many C-4's leak there too.

Pull driveshaft, jack up engine off trans. mount. Pull speedo drive and cable, unbolt tail housing. Scrap gasket, replace in reverse order. Done deal. If you do it replace the seal on the end and check the bushing too. It's alot easier to do it then.

Hard to believe that the new pan is warped in the same place. Did you try alittle Permatex on the gasket?? Just a little, I don't like RTV there, it squeezes into the pan too.

Kisner · 04-01-2001, 10:54 PM

Yep, already checked around the housing. It's not leaking anywhere else. If I wipe it completely clean where it's leaking around the pan, I can come back the next day and already see it oozing from exactly where the pan meets the bottom of transmission case. I'll take your advice, drop the pan and put a very small amount of RTV on the gasket and also put some plumber's tape around the bolts. I'll let you know if that fixes the problem. Thanks.

03-31-2001, 02:59 PM	#1
Kisner Registered Member Join Date: Nov 2000 Posts: 290	Transmission Pan Leaking I've been trying for 6 months to stop my transmission pan from leaking. Checked the entire transmission to ensure it wasn't leaking from anywhere else. It only leaks from one corner of the pan. I replaced the gasket and bought a new pan but it won't stop leaking. Is it possible I have a pit, divet, or hairline crack in the bottom of the transmission case? Any words of wisdom would be appreciated.

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03-31-2001, 05:42 PM	#2
Gearhead999 Registered Member Join Date: Sep 1998 Location: Oviedo, FL Posts: 992	If the dipstick tube goes in the case, and not the pan. It probably is the "O" ring on the tube or the tube is bent. When it goes in the case it is the right front corner. Is that where your leak is?? Another leak could be the lock nut that holds the band adjustment. They have a rubber seal that usually can't be reused. The seal is built on the nut and you have to just replace the nut. Sometimes the fluid will come through the pan bolt threads. Put alittle sealer on the pan bolts at the wet area. The likely hood of a hairline crack is remote. I would check what I said and if it isn't one of them. Clean everything with carb/brake cleaner REAL good. Get car in air and really eye ball it.

03-31-2001, 11:32 PM	#3
Kisner Registered Member Join Date: Nov 2000 Posts: 290	I've already checked everything you mentioned, to include every square inch of the transmission. It's only leaking where the pan meets the bottom of the transmission on the left-hand side (driver's side) rear corner. About ready to throw in the towel and take it to a transmission specialist. The original pan was extremely warped - maybe the new one was warped there also - guess I should have thoroughly checked it with a straight edge before I installed it.

04-01-2001, 10:02 AM	#4
Gearhead999 Registered Member Join Date: Sep 1998 Location: Oviedo, FL Posts: 992	You also checked where the tailhousing bolts on to the main body of the transmission?? It is an easy gasket to change. Have seen many C-4's leak there too. Pull driveshaft, jack up engine off trans. mount. Pull speedo drive and cable, unbolt tail housing. Scrap gasket, replace in reverse order. Done deal. If you do it replace the seal on the end and check the bushing too. It's alot easier to do it then. Hard to believe that the new pan is warped in the same place. Did you try alittle Permatex on the gasket?? Just a little, I don't like RTV there, it squeezes into the pan too.

04-01-2001, 10:54 PM	#5
Kisner Registered Member Join Date: Nov 2000 Posts: 290	Yep, already checked around the housing. It's not leaking anywhere else. If I wipe it completely clean where it's leaking around the pan, I can come back the next day and already see it oozing from exactly where the pan meets the bottom of transmission case. I'll take your advice, drop the pan and put a very small amount of RTV on the gasket and also put some plumber's tape around the bolts. I'll let you know if that fixes the problem. Thanks.