47RH in MDT vs AT545

[TBigLug]

I'm not an expeditor (no throwing stones please, lol) but a lot of you folks run MDT's and may be able to help me out.

Basically looking at either tranny in a stock (read as one without a lot of $ sunk in it) configuration. Will the 47RH work in a 1992 Topkick behind a 5.9?

Might be picking up a low-pro TK that has a 366 and a 545 in it, currently has a 24' box on it. Truck will end up being either a crew cab conversion with a donor cab from a '94 C3500 with a flatbed or I'll keep the standard cab and add on a ~60" flat top sleeper. Either way it'll have a 10' flatbed with a gooseneck ball and pintle hitch on the back.

I would like to (someday) repower with a 5.9. Not a mega power hotrod, just something that can pull my 4H gooseneck and fifth wheel camper. No mountains and I'm happy going 60-65 down the highway. Furthest trip I'll ever make is to TX to visit my daughter, again, pulling a fifth wheel.

Everyone says that the AT545's are junk and only good for around town stuff. I don't have the money to shell out for an AT1545 or a 3060. So, according to all the Cummins guys the only option is a 47RH so I can have OD and a lockup converter. But, they are all referring to light duty (2500 & 3500) applications.

So to sum up all the ramblings of a mania c , which transmission (in a stock take-out format) would be best in your opinion and why?

 

[pwrwagn]

I'm not an expeditor (no throwing stones please, lol) but a lot of you folks run MDT's and may be able to help me out.

Basically looking at either tranny in a stock (read as one without a lot of $ sunk in it) configuration. Will the 47RH work in a 1992 Topkick behind a 5.9?

Might be picking up a low-pro TK that has a 366 and a 545 in it, currently has a 24' box on it. Truck will end up being either a crew cab conversion with a donor cab from a '94 C3500 with a flatbed or I'll keep the standard cab and add on a ~60" flat top sleeper. Either way it'll have a 10' flatbed with a gooseneck ball and pintle hitch on the back.

I would like to (someday) repower with a 5.9. Not a mega power hotrod, just something that can pull my 4H gooseneck and fifth wheel camper. No mountains and I'm happy going 60-65 down the highway. Furthest trip I'll ever make is to TX to visit my daughter, again, pulling a fifth wheel.

Everyone says that the AT545's are junk and only good for around town stuff. I don't have the money to shell out for an AT1545 or a 3060. So, according to all the Cummins guys the only option is a 47RH so I can have OD and a lockup converter. But, they are all referring to light duty (2500 & 3500) applications.

So to sum up all the ramblings of a mania c , which transmission (in a stock take-out format) would be best in your opinion and why?

I spent years at a shop where we dealt with these.

The 47RH is ok, but it needs modification to work in your application. The lockup converter isn't strong enough, there's some hydraulic issues involved, and it needs a huge cooler setup.

The gearing isn't the best, either, for the 5.9 with a big load. You'll have to pick your final gears well.

There's some places out there that will customize one for you. I don't like to sound like I'm advertising, but if you google places that specialize in the Dodge / Cummins combo, and have a good reputation, you can get a bulletproof trans from them.

Here's the issues: The overdrive in some years needs strengthening. The torque converter needs lower stall speed, and an incredibly strong clutch - multi-disc is best. It needs a deeper pan with higher fluid capacity, and it needs a couple of internal parts replaced and some tweaking to make it shift more firmly.

Once you do those, it is incredibly strong and durable.