I have a 8.1 Vortec Engine with an Allison Transmission in a 04 Tiffin Gas engine Allegro Bay. I was told by somebody that the transmissions are calibrated for the chassis as it come from the factory. They then build the coach on it and put it on the road. Somebody told me that the coach needs to be recalibrated for the finished product. I was told that the RPMS on the engine run high (3500-4500 RPMS) while decending mountains on long declines in 3rd and 2nd gear if this is not done. Just got back from a trip to the West and saw this as a major concern. Recommendations please.
Bob and Ann
One HAPPY Schnauzer - Della
One FRISKY Chihuahua - Lola
2005 37 DB Allegro Bay
GM 8.1L (496 CID)
Onan 7000 Watt
2006 Suzuki Grand Vitara Toad
You have an Allison 5 speed tranny. When in Tow Haul (T/H) mode the transmission will help slow the vehicle along with the engine braking. I have a Duramax and those RPM's aren't a problem. I know nothing about the 8.1, other than it too is a workhorse.
Go over to the DieselPlace.com and you can read up on your 8.1/Allison combo.
First, who was the "someone" that told you this? If you have any doubts on anything regarding an Allison, take the coach to an Allison shop, NOT a RV shop, and have them scan it. You will be much happier.