Xtarder

[dbarton291]

A trans with a retarder would have the model designation MD3060R.
Some of the later transmissions might have only an E-number and a serial number.
You can go to www.allisontransmission.com, my Allison, and enter the serial number to find out exactly what model it is.


If you have an output retarder, the rear cover is larger, rounded and has a lot of cooling fins on it. There will also be a hydraulic accumulator and an air solenoid in the vicinity of the transmission. The output retarder housing also has an additional valve body on it. The cooler lines will also be routed differently on a retarder vs non-retarder.


If you've got an output retarder model transmission, you can't miss it the differences if you've seen a non-retarder.

[jcussen]

Originally Posted by RKins

That's a good tidbit of info to help people (I know my tranny does not have a retarder inside).

I took a pic of the nameplate on my tranny when I was replacing a sensor - where would you see the -R? My model says MD 3060.

My retarder coach had MD3060R where yours says MD3060.

[dons2346]

I'll guarantee that National did not put a transmission that has a retarder in that coach. It has a plain old exhaust brake

[V3600]

Originally Posted by Rockyv

New to me how do I now that when a use the switch that it works don’t fell a hold back like Jake brake

Sorry, your question makes no sense to me.

[Rockyv]

Thanks guys with the new info I will start looking at trans and Motor to see what brake I have

[dons2346]

You have a Cat 3126. Most likely a "B" designator
Your transmission is Allison MD3060


The exhaust brake could be made by a number of manufacturers