The M is used when pulling a trailer. When is the the most appropriate time to use this feature. Try going to Colorado in June and cross over Cinnamon Pass that drops into Lake City. No person wants to or needs to be inconvenienced by needing to have a rebuilt transmission on the road. Most folks say that once you go down this pass you will not want to go down it again. Is this purpose for this feature?
We can use all use help concerning the useage of the “M” and towing a 5th wheel trailer through the mountains and how this feature can help.
Most of the time Tow/Haul mode will do everything that you want it to do with the grade braking feature. If you wanting to put it in M mode to hold a gear longer then it wouldn’t hurt a thing. The allison is a very smart tranny and will take care of itself, if you put it in M4 it won’t let it over rev it will shift to 5 before it hurts anything, so i would say put it in tow/haul and take it easy at the top.
Most of the time, when towing a large trailer, the Tow/Haul mode takes care of everything. Other drivers tow in “M” mode, restricting upshifts. … by using this mode in windy hilly roads where we know the shifts would be changing quite often…In this situation many folks feel there was is no reason for the tranny to shift into 5th or 6th gear during this time creating a lot of unnecessary up and down shifting which can only add premature wear…leading to the need for a rebuilt transmission.
This is a really smart transmission. It has many programs in the TCM for different driving styles built into the main computer. Personally I find the extra buttons and options employed leave people confused. After rebuilding transmissions for over 30 years, it is my opinion and recommendation to leave the shifter in drive and let the transmission decide when to shift.
I have seen many people struggle with using the “M” button or the likes and forget to disengage it at highway speed, thus killing gas mileage and adding much further wear and tear to your engine and transmission.
Br a smart consumer. Always read your owners manual, and include reading Gottransmissions.com blog for information such as this. Enjoy.
