Allison 2100MH Transmission Manual Gear Selection/Engine Brake

[vettenuts]

We will soon be departing our CG and will have to go down a long twisty grade for several miles. This will be new to us. Here is my question, noting that I have a gas Workhorse with the 8.1 engine. If I select 2nd gear at the top of the hill and during our decent hit the brakes with the engine brake switch engaged, will it down shift to 1st assuming the engine RPM won't over rev? I have read the Allison manual but am not sure of how this feature works based on the description.

As a corollary question, does anyone know the maximum speed for each gear on the Workhorse W24 chassis?

[Skip426]

Originally Posted by vettenuts

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As a corollary question, does anyone know the maximum speed for each gear on the Workhorse W24 chassis?

Not sure if the grade brake will achieve 1st. gear, even if your already in second.
Have you tried inputting you trans serial number on Allison's home page.

Trans controller will up shift to prevent engine over revving , so engine red line in each gear , on the 8.1 , I'm thinking 4,600 RPM.
Check your speed in first at 2,300 and double it, same in second.

[vettenuts]

Thanks, will do that. I don't think I can keep my speed in check on some of those curves in 2nd.