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capnqball · 07-14-2013, 11:35 PM

I've read somewhere that 2500 rpm is the limit on EB, and somewhere 2900 rpm is the limit. Can someone or two tell me which is correct?

Skip426 · 07-14-2013, 11:45 PM

Transmission would up-shift to avoid, high RPM, engine damage , even with the EB on . Personally I'd be on the brakes to keep RPM in the 2100 >2400 range. I've got my 3126 manual , I know you've got the newer motor but I'm thinking the numbers should be similar.
Manual says 2900 max , downhill operation.

jauguston · 07-15-2013, 10:17 AM

The governor maximum rpm is 2400. The top engine speed range is 2640 rpm. At 2640 rpm the transmission will automatically upshift.

The 2900 rpm number only refers to engines with manual transmissions. You cannot go over 2640 rpm with the Allison it is programmed to upshift there.

The 2400 rpm and 2640 rpm numbers come from the printout from my ECM. My engine is a KAL96181 350 hp. The 2900 rpm number is on page 88 of the Operation and Maintainance Manual KAL1-Up (engine). You cannot force the engine to turn over 2640 rpm with a automatic transmission.

Jim

Skip426 · 07-15-2013, 10:34 AM

Thanks Jim, no mention in my manual of trans type , I knew the trans would upshift to protect the engine but didn't know the RPM.
I'll take notes.

jauguston · 07-15-2013, 10:57 AM

There is no direct reference to transmission type. There is reference to the maximum rpm allowed for the engine/transmission combination in my coach determined by the actions of the ECM. 2640 is as fast as you can get your engine to turn with a automatic transmission. The only way you can get it to turn 2900 rpm is to have it equipped with a manual transmission. Then you and not the ECM have control of the maximum rpm the engine can be made to turn.

Going down a steep hill with the EB on if the rpm keeps increasing because the hill is too steep for the EB to control the speed you are going when the rpm reaches 2640 the transmission will upshift. You cannot prevent that from happening. You have to use brakes. You need to reduce speed to a point where the EB can control speed by itself.

Jim