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Unread 03-08-2014, 05:51 PM   #1
robs7
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Forever Leaking Dana 300

I'm at my wits end with trying to seal the pan on my Dana 300. I've looked on here as well as Googled this and have tried just gasket, gasket with RTV, and just RTV. I can't seem to get the pan to seal. I've cleaned all the surfaces until they shine before I put it back together and also don't over torque the bolts. Any ideas? Rob

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Unread 03-08-2014, 06:04 PM   #2
jeepwhore
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How long do you leave the rtv to cure before you fill it up? Is the flange on the pan nice and flat.....especially around the holes?
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Unread 03-08-2014, 06:06 PM   #3
82JeepCJ7
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Check the breather hole. If its plugged, the internal pressure by the heated fluid will cause a leak. A friend of mine runs his breathers through an air/water separator then to engine vacuum. NEVER has a leak.
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Unread 03-08-2014, 06:07 PM   #4
robs7
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The pan is very flat. The last time I tried I used only ultra black RTV and let it sit hand tight for 24 hours. Then lightly snugged it up. The leaks always seem to be around the bolts on the tranny side of the pan no matter what I use. Rob

Sorry, I got that wrong. I waited 24 hours before filling it. I let the pan sit hand tight for only an hour and then snugged it up.
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Unread 03-08-2014, 06:12 PM   #5
dg6772
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Are you sure it's the pan. I thought mine was too; chased it for weeks. Turned out to be weeping from front output seal down to pan.

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Unread 03-08-2014, 07:40 PM   #6
only in a jeep cj
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The 3 places I always see them leak is the back of the main shaft , the shim area at the rear input bearing ( to the right of the main shaft), and the front yoke. All will run down and look like the pan.
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Unread 03-08-2014, 09:29 PM   #7
agear
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Ive done the bottom cover on mine 5 times and it always leaked. This last time I tried "the right stuff" for the first time. No gasket. It comes out of the can kinda whipped up and tacky and doesnt want to smear smooth. I was doing it in the light rain and was sure it was gonna leak but Lo and Behold it didn't. It's a winner in my book. These days I clean the surfaces good so in the end no residue gets on my rag with when I wipe it with brake cleaner and of course get of the old rtv etc. off. I waited atleast over night but can't exactly remember how much longer.
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Unread 03-09-2014, 03:38 AM   #8
Mike Romain
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Quote:
Originally Posted by robs7 View Post
The pan is very flat. The last time I tried I used only ultra black RTV and let it sit hand tight for 24 hours. Then lightly snugged it up. The leaks always seem to be around the bolts on the tranny side of the pan no matter what I use. Rob

Sorry, I got that wrong. I waited 24 hours before filling it. I let the pan sit hand tight for only an hour and then snugged it up.
It totally blows my mind why folks think putting a new torque or snugging up the bolts on a freshly dried glued together part is a good idea. Can we say how to blow a glue or RTV seal in one easy lesson?

Hey, you are not alone, I see and read of folks doing this all the time, usually in why does it still leak threads....

The directions on the Ultra Black RTV clearly state to torque the part immediately for a reason. Once it has set it is done. If you then go and tighten it again after it is set, you will blow the seal.

Also not using a torque wrench on the cover can make them leak easy. Saying you snug them up strongly implies you are just hand tightening them.

That said, I would also make sure the vent is clear as mentioned.
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Unread 03-09-2014, 06:30 AM   #9
CJ51973
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I would check the vent. I have all mine run to the firewall. I didn't have a filter and a spider or something made a nest. Almost pulled my tranny before I figured it out
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Unread 03-09-2014, 07:49 AM   #10
robs7
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Quote:
Originally Posted by Mike Romain
It totally blows my mind why folks think putting a new torque or snugging up the bolts on a freshly dried glued together part is a good idea. Can we say how to blow a glue or RTV seal in one easy lesson? Hey, you are not alone, I see and read of folks doing this all the time, usually in why does it still leak threads.... The directions on the Ultra Black RTV clearly state to torque the part immediately for a reason. Once it has set it is done. If you then go and tighten it again after it is set, you will blow the seal. Also not using a torque wrench on the cover can make them leak easy. Saying you snug them up strongly implies you are just hand tightening them. That said, I would also make sure the vent is clear as mentioned.
Just so that I understand you correctly. You say to immediately torque the pan after applying the RTV correct? My ultra black directions call for assembling it immediately and then tighten another half turn after curing for one hour. Maybe that's what I am doing wrong. Maybe I'm blowing the gasket with that half turn an hour later. The vent is clear and ran with new hose up the firewall. Thanks, Rob
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Unread 03-10-2014, 06:12 PM   #11
robs7
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I just wanted to say thanks for the help. I sealed it over the weekend and used "the right stuff". Torqued it immediately and resisted the urge to snug them a little bit more! Leak free! Thanks again. Lesson learned. Rob
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