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Now that I'm actually driving the 85 more and more I have noticed it smoking (sometimes bad) from underneath the car. I discovered it is leaking automatic transmission fluid onto the exhaust when I drive it. I cleaned everything really good and had my son sit in it and rev it up while I laid up under it. Nothing leaks while car is stationary.
I did notice that behind the small square block that is bolted on pass side of OD unit that of the coolant lines goes to there are 2 steel rods (pencil size diameter) sticking out of the transmission case about half an inch and almost looks like they were punched through from the inside. All the pictures that I have looked at, show the end of the rods are flush with the case. I did not notice the rods protruding out like this when I had the transmission out of the vehicle. Could fluid be leaking from around these rods? The OD unit worked at it should the few times I actually engaged it.
Are these the steel pencil nubs you are talking about?
I found this image from another forum because it was a huge mystery as to what these were. They shouldn’t leak though. My guess is that they’re the entry points for molten metal during a sand casting process. I could be wrong, though.
When my overdrive leaked onto the exhaust, it turned out to be a faulty gasket which was leaking little drops as I was driving. Is your gasket perfectly clean? No rim of ATF around the pan?
I serviced the transmission before reinstalling it back in car. The OD had no filter and a ton of RTV around the pan. I removed the RTV and installed the proper filer and gasket. I will check the gasket again.
Thanks for the quick reply. You guys are a huge help.
Don't sweat the rods there supposed to be there, clean up everything and make many trips under to find the leak. It's common to have output shaft seals leak,
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Originally Posted by AGENT 86
Clean well and use permatex The Right Stuff with no gasket.
Thanks for all the tips, just did the fluid change on our overdrive, pretty easy really, bought new filter used great stuff for the gasket, merc / dextrose fluid, filled followed gasket instructions no leaks.
Filled up to fill hole, rotated rear wheels 20 revolutions, toped off fluid again
I removed the pan and cleaned it thoroughly along with the surface of the transmission. Let it sit overnight and refilled. Drove it for a while and no smoke so I figured leak was fixed. Got on it on the way home and looked like it was on fire with all the smoke. Tried to back in the driveway and the brand new clutch apparently decided to go bad. Had to shut it of to get it in reverse. Anyway when I got it parked it was dripping auto transmission fluid from everywhere under the car. Apparently my leak is under pressure and spraying from somewhere. I'm gonna walk away from it for a while before I use it for target practice lol.
Wow that sounds extremely bad… sorry to hear you’re having so much trouble with your Doug Nash transmission.
Ive searched far and wide on these forums through decades of posts to educate myself as much as possible on these transmissions. I can’t say I’ve heard of a problem like yours before. Typically the vent on top of the OD should release pressure. Unless it’s blocked, I can’t say I can think of a reason it would just blast out all over the bottom of the car.
There are people on this forum who have physically been inside these transmissions. I have not. Perhaps they can be of more help.
4+3 leaking
