Common Tranny Leak Spots?

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danielb927

danielb927

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Hey guys, I have a tranny leak that I need to find and decide if I can fix it or not. When I bought the car in May the fluid was about a pint low but the guy I bought it from said it didn't leak. I filled it up and it had a slow drip while I worked on some other problems. Took it out to some friends, we found that the tranny pan was pretty loose, so we tightened it up and it seemed like it wasn't really leaking anymore. But, at this point it was about a quart low, so just a couple of days ago I filled it up to full before going out for a cruise. I got home, check under the car after a couple hours, and it seems like no leak. But, next morning I check, and there is enough fluid on my cardboard that a puddle has formed. Checked today and there is even more fluid. This is a pretty big-time leak. Anyways, is there a kind of leak that can happen only when the car is cooled down? Could the transmission be getting too hot and making a leak worse over time?

Also, I have been putting Dextron/Mercon fluid in it at the recommendation of the previous owner, but i saw at advance they had ATF +4 fluid which said it was for Chryslers, should I be using this?
 
Maybe check the lines. I thought my transmission was leaking too until it was pulled and I saw the split in one of the lines.
 
Check where the dipstick tube mounts to the tranny.. mine leaked like crazy there...
 
Pan, Dip stick O-ring and front and rear seal are were they leak
 
Mine also leaked where the speedo cable goes in...lol.. although that leak wasnt very bad...
 
I just spent 1300.00 to rebuild my trans and it leaks Lol! I found that the front seal leaks alot.
 
Don't forget the shifter seal. You need to get everything cleaned up real good to determine the source.

Slappy - your front seal shouldn't leak after a rebuild unless the new seal got trashed on the install or the front pump bushing is worn.
 
Thanks guys, I will try to take a look around the dipstick and see if maybe the pan has gotten loosened up again. It seems to have a ding or two in the edges so that could be a problem, I may try to bang them out or get a new pan/gasket since I'm losing a quart of fluid every time I park for a few days anyways.

Just wanted to ask again, is Dexron/Mercon fluid OK, or should I be using ATF +4?
 
I was going to say the shifter seal too.
There is an inner and an outer shaft, so there are 2 seals there.

The neutral safety switch was leaking right out of the wiring pins on one I had a few years ago.
 
I will try to figure out if there is a leak at the dipstick or elsewhere, hopefully will post some pics later, I can see a little has leaked at the rear seal.

How much to take it to a tranny shop and have them replace the pan gasket, seals, other leak spots?
 
Took a look today, and I found a threaded hole on the front part of the tranny (torque converter cover part?) with nothing in it! This seems a little strange, here is a picture. Had her jacked up and forgot to look at the dipstick connection (doh!) but there is a lot of nasty stuff all around the transmission so my suspicion is it has a lot of leaks. It drips in spots from the front all the way to the mount in the back I am considering going to a tranny shop and asking them to pull it and replace all the gaskets and seals they can find.

Mystery threaded hole:
p1010595s.jpg


Gunk buildup on drivers side front of tranny pan (line did not seem split):
p1010597w.jpg


Another threaded hole (drivers side rear just above tranny pan) but does not go into transmission that I can tell.
p1010599r.jpg
 
Don't worry about the hole. There are a number of bosses and holes that are used in different applications. The most obvious problem area in the pic is the pan "gasket". Looks like someone went to town with RTV. Drop the pan, get all that crap off and use a proper gasket after making sure the pan flange is flat. The edges of the pan look buggered up.
 
Go buy a couple cans of spray brake cleaner. Get under the car with an old tshirt and clean everything up. Then leave it sit overnight. A leak that big, will most likely show itself, without the car having to be started.
Be mindful that brake cleaner will slightly swell the dipstick o-ring, stopping a leak, at that spot, for only a day or two. I just did this with my truck and found the dip tube to be the culprit.
 
That looks like a silicon mess, as sst3193 said, drop the pan, get a reusable gasket, put some gasket tack on the pan and slap it back in, also, where the shift levers are, check there, I had a drip for a while put a qt of fluid and now it dumped everywhere, the shifter seal is bad and it just flows out of there. also where your tranny lines go in, pull them off and wrap some teflon tape and reinstall them.
 
Got a gasket today, I will be dropping the pan, straightening it out if it needs it, and putting a new gasket on.

It waits a day after I drive it, then most of the fluid just drops out overnight. I put a pint in on Sunday, drove it Sunday, Monday, Tuesday, no leak as of Wednesday afternoon, but Thursday morning rolls around and that pint is making a nice big puddle on the garage floor! Looks like the drivers side, which could be Shifter linkage, kickdown linkage, or just that nasty spot on the gasket. Whatever it is is swelling up when I drive it and it gets hot and takes about a day to cool down and contract again fully, but then when I first put the pint in it was cold, and didn't leak in the 2 hours before I drove it.
 
Okay, so I went and replaced the gasket today. Not much to say there, it was already a rubber gasket and the gunk around the edges I think is just buildup from the leaks. The leak seems to be coming from either the front coolant line outlet, or the kickdown/shifter linkage area. There was a huge amount of nasty buildup there, old hardened fluid I think. Filled it back up, put in the Lucas Oil stop-leak by recommendation of a local car enthusiast I was talking to, so hopefully it works! The previous owner didn't drive it much, so the seals may be in need of a treatment (I hope).

If not, I will probably take it somewhere, it doesn't look like it's too easy to get at that coolant outlet or the kickdown linkage seals, they're up there pretty good!
 
You want something Dexron III, which is now part of the Dexron/Mercon spec. Check the bottle. Don't use ATF4 in anything that doesn't specifically call for it. It will attack your seals.
 
Update: gasket blew out, I had a car-sized puddle of tranny fluid on my garage floor. Any idea what I did wrong when I put the new gasket on? Put tacky gasket sealant on it as suggested, it looks like it blew out on the passengers side front. The rubber gasket is actually torn around one of the bolt holes. Used Tacky Gasket Sealant type 97
 
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