So with the 727/518, when starting with a load, you should pull the shifter physically down to the 1st gear detent?

 

I always do, especially if your loaded heavy or pulling out on a hill.

Kwell27,
Sounds like you pull alot of heavy loads, with 3.07 gears, thats asking alot of the transmission when starting out. Do you start out in D or 1st?

 

Kah68 i would suggest using a roll control or line-lock as you may. There are 100% duty cycle ones that you could use like air brakes. The after trans drums always gave us problems on our tow truck and grummins. if you forget to take them off once they are basically done, shoes bend or just get smoked. You could also just use your PARKING BRAKE, if it still works. Or here is the idea i like, mount a disk brake with manual caliper as your brake on your diff just after the driveshaft just like the monster trucks.

 

https://www.dieseltruckresource.com/...e-t190249.html

He used a TH400....

 

LOL, He was also shifting it at 5,000 RPMs..... The killer is the RPMs, not the Torque.

 

Buicks run th400 with 455 that make a lot of torq down low

 

From what i gathered the problem with the low end torque in any automatic trans is simply how a diesel works. Since most transmissions are designed for gas motors they have many problems when an egghead decides to put a diesel behind them and "make them work".
A gas motor (455 buick for instance) tends to bog down when the trans shifts, then climbs the rpms again until the next shift point.
With a diesel, esp our turbo diesels, the transmission shifts and the diesel grunts and groans and makes even more power/torque with very little loss in rpm. This is exactly what everyone is talking about when they say low rpm torque. Without taking your foot off the pedal, there are few things to give if the motor doesn't. The torque converter, the clutch-packs or the tires, without mentioning things that break.

My though on how a trans would survive is to make the diesel engine bog down when the trans shifts and let it climb the rpms again. Some sort of studder switch or kick down for the fuel. Almost an automatic "remove your foot off the gas" solenoid. The newer diesels can do this electronically.

 

What kills autos behind a diesel is the low rpm big torque useage, yes, they can make decent line pressure at low speeds, but, the pump is turning considerably slower at low speeds, meaning less fluid is moving through the cooler, and less flow is avalable to apply pressure to the clutches and bands. Making an auto live behind a diesel is a VERY different ballgame than making one live behind most gassers.
A friend of mine has a 557 Ford(460 based stroker) that's built to be a low rpm monster, I'm talking over 600 ft/lb by 2000 rpm, not quite a Cummins, but still a good amount of torque down low. He couldn't keep a C6 alive cool and alive behind it, no matter how built the transmission was.