727 questions

[Darrell]

There was brief discussion about this in one of my other threads but I wanted to start a new thread to stay on topic. I have two 727 transmissions. One is original to my 65 New Yorker and the other is out of a mid 70s motorhome. Originally I was going to swap input shafts so I could use a hi stall converter and keep my stock shifter. However, based on another discussion I am thinking about using the motorhome trans due to the heavier duty parts, ability to run a transbrake,etc. and then using an aftermarket shifter. I believe I can modify a shifter to work with my console.

The only issue i see is the motorhome trans is a shortshaft and has a parking brake on it. Will the tailshaft and tailhousing from my original transmission swap over to the short shaft motorhome transmission? Is there anything else I need to be concerned with?

:sSig_thanks:

 

[440_Magnum]

I think there are some red flags there since the '65 would have been a dual-cable shift setup from the factory and (I think....) still have had a rear hydraulic pump in the tail housing.

65-66-67 were years of pretty rapid changes to the Torqueflite, and I honestly don't remember everything that happened, but here's my best recollection. 65 was the first year when the gummint required a standardized (P-R-N-D-2-1) shift pattern that effectively outlawed pushbuttons, but Chrysler retained the dual-cable controls for pushbuttons that one year and used special "1965 only" shifters to control them (I owned a '65 300L and saw/studied all that kludge, but fortunately never had to mess with it). Like I said, I think it still had dual hydraulic pumps, too, but I'm not as certain. By '66, they had the single input lever shift on the transmission and definitely deleted the rear hydraulic pump driven by the tailshaft, but still had the switch for reverse lights on the column (or in the shifter) and neutral safety in the trans. By 67 (68?) they'd moved to a combo neutral-safety/reverse light switch in the trans case, which makes it ticky to swap valve bodies between 66 and any other year (you have to trade the "rooster-comb" shifter detent to stay with the '66 case and vice-versa)

 

[Flatlander]

I've done the swap to a late model 727 in my '65. Some of the questions I can answer, some I cant.

First thing is that a rubber transmission mount from the late trans is needed, along with the bolts that attach it to the transmission. I did fit the later transmission cross member, but only because I had one in better condition than the original.

The speedo cable needed changing. The fitting at the transmission end is different on the '65's, and wont fit.

Everyone told me that I would need the new type switch with 3 connectors, as the old wouldnt fit. That was wrong, because the old type one does, and works. Or at least, it does on mine.

For the shifter. Imperial Services do a conversion kit, which makes life easy.

Kickdown. I used a BPE kit to make things easy. The chances of finding a stock type kickdown locally are non-existent.

Assuming an original engine in the '65, it would have a forged crank. The mid 70's one might have had a cast crank. To be certain, use a neutral balance converter, and flexplate for forged crank.

 

[twostick]

Don't buy into that 4 pinion vs 3 pinion planetary myth. The pinions aren't the weak link, the aluminum splines in the hub are.

The MH trans might/probably has an extra çlutch disk in the çlutch packs that may or may not fit in the drum of your 65 trans but for what you have in mind you should be putting a billet drum in there. In any case the only parts I would consider superior in the MH trans would be the clutches and the front pump.

IMHO way less work to upgrade the 65 trans than to convert the MH trans to the 65. Not even sure you could use the 65 tailshaft housing and output shaft because of the cable park and rear pump difference.

Kevin

 

[Darrell]

Thanks for the info guys. I totally forgot about the rear pump in my current trans. I guess its time to go back to plan "A" or maybe plan "C"....