Community Forums

dbear · 09-15-2016, 08:19 PM

Will a 1350 RDS directly replace a 1000 RDS, or is there more to it than just bolt up, plug in, and go?

BFlinn181 · 09-16-2016, 01:39 PM

What engine are you talking about? If it's computer controlled, you'll probably have to have the ECU and the transmission programmed together. Even if an older mechanical diesel, you'll need to have the shifting points programmed for the engine torque and HP.

I'd start by contacting Allison to find out if the dimensions and mating points of the 1000 and 1350 are compatible. There's also cooling, electrical, and shifting differences that will have to be considered.

dbear · 09-16-2016, 07:06 PM

I was kind of figuring there was more involved. Nothing is easy when it comes to automotive stuff anymore. Thanks for the feedback.

dbarton291 · 09-21-2016, 10:46 AM

Go to the Allison website. I think you'll find that the 1350 has only different ratings. The external dimensions and hookups are all the same. The guts are the same. One thing you will have to make certain is you have the same torque converter model in the one you are putting in.
If the vehicle you are putting it in already has a TCM in it that was working fine with your engine, you won't have to reprogram that. Both models are RDS and they are both close ratio gearsets.

dbear · 09-22-2016, 05:32 PM

Quote:

Originally Posted by dbarton291

Go to the Allison website. I think you'll find that the 1350 has only different ratings. The external dimensions and hookups are all the same. The guts are the same. One thing you will have to make certain is you have the same torque converter model in the one you are putting in.
If the vehicle you are putting it in already has a TCM in it that was working fine with your engine, you won't have to reprogram that. Both models are RDS and they are both close ratio gearsets.

Thanks for the reply. I'd already been to the Allison site.That's how I came up with the 1350. I'm a little disappointed that I did not find an email contact for technical/applications support. The only contact I can come up with is a phone number for my local Allison rep. They didn't list an email contact either. I'm thinking it might be easier to just stop in with my questions.

dbarton291 · 09-23-2016, 05:28 AM

I understand. Allison headquarters isn't set up to deal with retail business at the home office. They do all the retail/aftermarket through their distributors and dealers.
It's really the same for most manufacturers of components. Cummins for example works throught their distributors but those guys feel like the home office because Cummins owns a lot of their distributors. Allison isn't that big.

Arch Hoagland · 10-02-2016, 10:08 PM

I'm curious why you want to swap it out.

dbear · 10-10-2016, 05:29 PM

Quote:

Originally Posted by Arch Hoagland

I'm curious why you want to swap it out.

Increase the GCWR by 4000#.

BFlinn181 · 10-10-2016, 06:43 PM

Quote:

Originally Posted by dbear

Increase the GCWR by 4000#.

From Wikipedia (I know, not always reliable)

"The GCWR is a function of the torque output of the engine, the capacity and ratios of the transmission, the capacity of the driving axles and tyres, the capacity of the radiator, and the ability of the chassis to withstand that powertrain torque."

Changing the transmission is one factor of GCWR, (which is set by the manufacturer) what are you doing for the axle ratings, radiator, and braking, etc.??

Why not just buy a larger RV??

dbear · 10-11-2016, 04:38 PM

Quote:

Originally Posted by BFlinn181

From Wikipedia (I know, not always reliable)

"The GCWR is a function of the torque output of the engine, the capacity and ratios of the transmission, the capacity of the driving axles and tyres, the capacity of the radiator, and the ability of the chassis to withstand that powertrain torque."

Changing the transmission is one factor of GCWR, (which is set by the manufacturer) what are you doing for the axle ratings, radiator, and braking, etc.??

Why not just buy a larger RV??

This is in a class 5 TV. Identical engine, brakes, frame, tires, axles, gear ratios... are used in higher gvw models with higher gcwr Allison models. The limiting factor for the model I am possibly considering is the Allison 1000 RDS.

msturtz · 10-11-2016, 11:34 PM

It is common for the transmission to be the limiting factor. For example The Thor Palazzo 33.x models have an Allison MH2100 transmission with a GVWR of 26,000# and GCWR of 30,000#. If you look at the data plate the ratings are 10,500# front and 17,500#. This should equal a GVWR of 28,000# like the 35.x and 36.x models. Those models share everything the same except the transmission is an Allison MH2500 and the engine was de-rated to 300HP from 340HP. It is easy for OEMs to swap out a transmission and de-rate an engine to save money without engineering changes. If an OEM starts changing suspension components that is not going to save much money and will complicate assembly.