Running in 5'th gear

[rvjimmy]

Latley I have been expiermenting by running in 5'th gear on my 6 speed allison. I only do it on the 2 lanes and when I go 55 to 57 MPH. It seems to get a little better fuel mileage as it does not shift up and down and up and down all the time. Does anyone else do this and does it hurt anything.

[edgray]

YES, and no it won't hurt anything. Your motor "may" actually run better at the slightly higher RPMs. Ed

[MaverickBBD]

According to Alison on the MH3000 (and probably the 4000) Fifth gear is an overdrive and Sixth gear is an "over" overdrive. That is one of the reasons your coach goes to Fourth so quick when you start to pull a climb and why you get out of it so fast when in the economy mode.

[Gary RVRoamer]

Mine is usually in 5th gear at those speeds anyway. Have to stay around 60 to keep in 6th gear. If I gradually slow down from 60+ it stays in 6th to around 56, but any pressure at all on the go pedal forces a down shift.

[1ciderdog]

For what it's worth: On my 2004 Cat 330 the Allison shifts into 6th no lower than 55 and will downshift into 5th about 53 mph. It appears the ratio is very close between 5th & 6th and I tend to leave mine in 6th unless it is hilly and it keeps shifting to maintain the set speed. I wouldn't think it would hurt the transmission or engine at the speeds you mention and I would be interested if you measure the actual difference in fuel economy.
Safe Travels
Bob

[Wayne M]

RVJimmy,
Is there a "mode" switch on your push button selector?
If there is, and you are on relatively level roads, or just a gradual rolling road, hit the mode switch. I little red light should come on and indicate it is in "economy" mode. This should keep your shifting to a minimum depending on the terrain. When I find that I'm still shifting up and down, that means the hills are a little steeper and I'll take it off of economy by hitting the mode button again. As stated, you will not hurt the transmission by keeping it in 5th gear.

Not sure on your 2002 model.