HAMBers, I have a trans leak making me nutso. I keep thinking I know where the leak is but after fixing the spot (speedo cable output, dipstick, rear band apply shaft) It still leaks. I run the trans through the gears while driving the car till hot and then top up to the hot mark on the dip stick with the engine idling in neutral. The fluid level is fine till the car sits. Here's the questions - After sitting a few days to a week the fluid level on the stick goes way up. I've assumed it's due to converter drain back because after driving the car the level on the stick goes back to were it was when I topped it off originally. So is converter drain back normal on a A-727? I don't know the year of the trans, but it's the common cable shift type from the 60's/70's cars and trucks. And Is it impossible to not have a leak when the fluid level gets above the top of the pan after the converter drain back? The Mopar I had before this one seemed to have the same converter drain back but didn't leak. I'm stumped.
Bump. I had one that did it as well, and I don't know the answer, but heard tell of some type of check valve in the front pump or passage feeding the front pump
I have the same problem with my 727, I have to remember to ask Fireball transmissions this summer if there is a solution. Bugs me too, no problem day to day but if if I don't drive it for a week, BANG, there's that puddle. I guess I'll just have to drive it everyday.
i have been dealing with the same issues for years, everyone on my "B" body forum says its real common but it drives me crazy, funny this is it leaks more on a flat surface than wha it's parked on a hill.. i guess that's what they wanted the performance cars loaded on the lower ramp of the delivery trailers
Crap! Well, at least I'm not the only one. I'll give this one a try on Moparts and see what comes back. If it's anything useful I'll relay it to here...
Yes, over time the converter will drain down into the pan and cause the transmission to appear over full. Put a fresh piece of cardboard under the car and mark some reference points, and when the leaks appear you will be able to trace it to the leaky spot on the transmission, engine, or power steering. Dave.
Check out the shifter shaft that goes through the casing. It has a tendency to leak. Rather a simple cure if it is. Pull the linkage off and replace the seal. Don't even have to drop the trans. Had a few leak like that over the years, and not a severe leak at that most of the time. I also know that there is more than one seal avaliable for those things.3 Good luck. Len
Hey gilby great sticker- what's the story on that i.e. how did you come by it as they would have all been removed by the dealers. And it looks like you have your share of 60's Dodges-great stuff.
Same issue on my 727. It marks its spot worse than my old VWs! I don't notice a significant loss off fluid which is a major bummer. I clean the whole thing off and wipe it down when I'm underneath but it's always there next time I'm under. I do see a drip forming at the speedo cable area usually but the entire underside of my trans is always oily. From pan on back. NAES
If the leak seems to keep coming back to the speedo cable area don't forget that there's more than one place for fluid to seep thru. IIRC there's an o-ring that seals the speedo driven gear sleeve to the trans case. Check the bore where the sleeve is installed closely and make sure there's no gouges, scratches or pits on the machined surface or sharp edges that might damage the o-ring when the sleeve is installed. Then remove the cable from the sleeve and take out the driven gear. Inside the sleeve there is probably a small lip seal that seals the sleeve to the shaft of the driven gear. Before replacing the seal inspect the shaft of the gear for wear or roughness where the seal rides on the shaft. Also check the bore of the sleeve for wear. They can go a bit egg-shaped after enough miles, especially on the gear end of the sleeve.
More than likely, it is the shifter shaft seal. To do this right, you need to drop the pan and remove the valve body. Loosen the shaft and remove upwards. Pull the old seal and install the new seal. Reassemble in reverse order. I've had several TF transmission leak from this very spot, and I need to fix my o/t '79 Dodge van, because it also suffers this problem. As long as you keep fluid in the trans, the leak will do nothing other than spot the driveway and annoy you. I let this problem go on my Coronet for 20 years before I got around to taking the two hours needed to fix it!
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