727 Transmission Information

[Bill Duster]

I'm putting my brother-in-laws project car, 76 Duster, back together and I have two transmissions to chose from. A '79 360 with 727 that came from a car, but I know nothing else about and a '73 727 that came out of a small RV with 22k miles.

Anyone know what the stall speed might be on the RV torque convertor?

Also - Would an RV-Truck transmission have heavier duty bands or clutches than a 727 car trans?

Any help from you Mopar guys would be greatly appreciated. I might even keep the car myself.

 

[DDodger]

..........or put the car converter into the truck trans.........

Make sure one is not a lockup.

 

[Bill Duster]

..........or put the car converter into the truck trans.........

Make sure one is not a lockup.

The car trans is reportedly a 79 which i think was the first year for the lockup converter. Do you know how to tell the difference? Part number?

 

[transman]

I'm putting my brother-in-laws project car, 76 Duster, back together and I have two transmissions to chose from. A '79 360 with 727 that came from a car, but I know nothing else about and a '73 727 that came out of a small RV with 22k miles.

Anyone know what the stall speed might be on the RV torque convertor?

Also - Would an RV-Truck transmission have heavier duty bands or clutches than a 727 car trans?

Any help from you Mopar guys would be greatly appreciated. I might even keep the car myself.

From the factory, the RV transmission might have either waffle or radial lined friction plates in it. It may even have the front drum that holds a couple of more friction plates if the RV was big block powered. The bands, with the exception of the HEMI band were all the same from 1962 to 1989. I say might have, because until you tear it down, it's impossible to say for sure.
Stall wise on the converter a lot depends on what engine the RV had. The stall could range from about 1800 to 2200 stall.
If the 79 is the factory original converter it had a decal on it, either a round one that say either LS lockup or HS lockup. If the decal isn't there look at the input shaft of the transmission.

 

[Penstarpurist]

Wait, am missing something here? I admit I've not seen everything or a transmission expert but I was under the impression that r.v and truck transmissions were generally short shaft or an external yoke like on a rearend. I know the last few engines I bought that were truck, r.v based that had the trans attached were short external yokes. I'm I wrong on this or has it just been my luck everytime?

 

[70aarcuda]

my 77 dodge class C motorhome has a normal 727 tail shaft on it

 

[fishy68]

Bill Duster here's a picture showing how to tell a lockup transmission from a non lockup. The top picture is a lockup input shaft. The bottom is not a lockup. You can see how the lockup trans has the end of the input shaft turned down smooth. My guess is the 73 trans has the potential for being a stronger unit. It also may have 4 pinion planetaries where-as the 79 unit most likely has 3 pin planets.

 

[fishy68]

Wait, am missing something here? I admit I've not seen everything or a transmission expert but I was under the impression that r.v and truck transmissions were generally short shaft or an external yoke like on a rearend. I know the last few engines I bought that were truck, r.v based that had the trans attached were short external yokes. I'm I wrong on this or has it just been my luck everytime?

It's been about 1/2 and half from what I've ran across.

 

[Penstarpurist]

Thanks for clearing that up for me. I guess I've only run across the shorty truck/van r.v style trans so far. I've even seen long shaft style external styles. One that a guy said came out of a car. I guess chrysler has built several styles.