Leaking transmission

[B Taylor]

My 65 Dart GT slant 6 904 auto is leaking. I backed into the garage today to do a little work on the rear wheels, when I pulled out I found a good puddle of tranny fluid and checked it was coming out of the bell housing.
My issue is: do I just pull and replace the seal? Or what I am more apt to do is to pull it and have it rebuilt (I'm at 123K) . Or the nuclear option of pull it all and find a 273 engine and tranny and just upgrade.
What is the basic cost of a bench rebuild at a tranny shop?
Are there any major changes needed for a V8 swap?

 

[AJ/FormS]

Well if it's coming from the BH and it's trans oil, then it would have to be the front seal. It's a bit-O-work but $20 should cover it.If the trans is otherwise working,I see no problem with slamming it back in. But before you do check the convertor hub for cracks in the corners of the pump-drive slots.
But I suppose you should be informed that the oil could have just come out of the vent which is also in the BH. If for some reason the trans was overfilled or if the convertor drainback checkvalve had failed, and you perhaps jacked the back up high enough that the oil just spilled out of the vent;well then nothing is really wrong,well other than the high, or temporarily high, oil level.
So then you might want to give it a good wiping, then let it stand for a few hours. Then with the engine off, check the oil level. It should be a little low,not 6 inches up the stick,lol. After the level has been thus checked,put on the park brake,start her up, put her in Neutral, and let her idle for a few minutes,then read it again. It should be normal to a bit low with cold oil. You may have to dip and wipe several times to get a genuine reading. You did put on the park brake right?

IIRC; pre66 valvebodies did not have the drainback check valves, so a high oil level after sitting for a few hours would be normal.

 

[AJ/FormS]

Are there any major changes needed for a V8 swap?

Well that depends if you're piecing it together, or if you have a donor-car, and what the end-goal is.
To piece it together, you would need the correct engine brackets and insulators, the exhaust manifolds and a new exhaust system. Then you need to hook up the carb so it and the kickdown all work properly, and cannot hang up, wide open. Then there's electrical,cooling and fuel to deal with. And an air filter system.
And after that, there's suspension steering and brakes to deal with, and probably a suregrip and tires. And seat belts I guess, cuz even a 273 will nearly double your power.

 

[B Taylor]

Well I pulled the tranny and you were right. I had the rear jacked so high it was coming out of the vent. Cleaned it up and just stabbed it back in. This car has been really good and I think I have been waiting for the hammer to fall.

 

[AJ/FormS]

Whoa....... You mean I guessed right?
I guess I'll go out and get me some lottery tickets then, seeing as how I'm suddenly lucky,lol........
Glad it was cheap and reasonably easy.

 

[TrailBeast]

Well that depends if you're piecing it together, or if you have a donor-car, and what the end-goal is.
To piece it together, you would need the correct engine brackets and insulators, the exhaust manifolds and a new exhaust system. Then you need to hook up the carb so it and the kickdown all work properly, and cannot hang up, wide open. Then there's electrical,cooling and fuel to deal with. And an air filter system.
And after that, there's suspension steering and brakes to deal with, and probably a suregrip and tires. And seat belts I guess, cuz even a 273 will nearly double your power.

Eh, minor details.
I don't think I ever jacked a Mopar up that high.
How high does it take to dump fluid?
Was it run in the air and foamed it from fluid being up around the drums, overfilled or sat awhile and backfilled before it was jacked up?
Overfilled, sat and then jacked up?

You were still right no matter which.

Just curious.

 

[AJ/FormS]

I think the convertor drainback checks started in 66.
So if the TC pukes 1/2 it's fluid back into the 904case,well,you know there' not a lot of extra room in there! And OP's Dart is only a 106wb IIRC. And it's got slanty bars in it. And probably 13's. And maybe the floor was not level.
So I don't know.
lol
It happened to me once, and I remembered it, that's all

 

[BillGrissom]

My "wait and see" procrastination would have won again. Too bad you didn't change the front seal while you had it out since that is easy and the rubber lips get hard and crack, plus probably costs $5.

A 273 V-8 swap is not the "just" than many here relate. You also need a V-8 steering cross-link (some say most 1966 slants had them), and a 64-66 small-block oil pan to clear the linkage. Your shift cable would probably work with a 65 small-block tranny (1 yr only valve body, but your slant valve body should interchange). If your slant was factory AC, it probably has a throttle cable, which may reach a SB carburetor. At least your K-frame will work, if you have early-A SB engine brackets, and your driveshaft and rear-end would work.

 

[Dartswinger70]

Put a 4 speed in it...they leak too, but the oil is thick as molasses and not under as much pressure.

 

[AJ/FormS]

Put a 4 speed in it...they leak too, but the oil is thick as molasses and not under as much pressure.

They (the 4 speeds) occasionally leak from the NSS, right thru that black stuff. I clean it up, crazy glue it and that's the end of it. I tried using synthetic once, which was sort of a disaster,lol.