Allison Transmisson Model MD3000MH

rocmoc wrote:

jimrose wrote:
Just a little more clarification, The tran went into safe mode three times in the last two times we were out. Also I leave the exhaust brake on all the time. The last time for safe was after coming down several blocks of a steep hill at slow speed with the tran in 2nd. I will call shop Monday to see if the ECM was rebooted. Thanks for all the thoughts so far.

This isn't the first time I have heard this. The previous owner of our Rig also drove everywhere with the exhaust brake on and burned the tranny up by 45,000 miles. He was told by the repair shop NEVER to leave the exhaust brake on, just when you need to slow down or stop. When we bought the rig it had under 50,000 miles on it with less than 5,000 miles on the newly rebuilt tranny (have the invoice where he paid $5,000). We now have over 60,000 miles on the rebuild / 5 years without any problems. AND we have pulled some HUGE grades & loads in very remote locations. I would still try what others have said as you nothing to lose but a lot to gain. Good luck!

rocmoc n AZ/Mexico

IMHO this doesn't make any sense. An exhaust brake or a compression brake isn't doing anything UNLESS you are slowing down or stopping. Having it on when you are cruising on the highway shouldn't have any effect on the transmission until you let up on the pedal.

I can see someone arguing that the repeated downshifting that occurs could cause transmission wear but I'd be rather surprised if many motorhome owners drive their vehicles enough for this to be an issue. Remember these transmissions are designed for buses, garbage trucks, etc, vehicles that run all day upshifting, downshifting and idling.