Community Forums

melvonnar · 02-10-2009, 06:52 AM

The motorhome I just bought has overdrive; I tow a small pickup.
When towing, do I engage the overdrive or do not use the overdrive?
It seems to shift up and down a lot if I leave the overdrive on.

BaldOldBob · 02-10-2009, 07:23 AM

I'd say listen to what your motorhome is telling you. Our toad, before it became a toad was a tow, as in towing a boat that is. It has overdrive and I wasn't sure about whether to use it our not. It did good on the straight and level, but add in some ups and downs, and it was always shifting. I figured it knew what was best and so only used overdrive on the flat stretches.

As always, your results may very.

doc · 02-10-2009, 07:35 AM

Consider adding another cooler to the transmission. The heat of the constant changing will get you.
I hauled equipment for a local dealer with a gooseneck flatbed and my PS F-250 for a while. Forgot and left it in OD for several miles on one trip and when I stopped at a red light, the ole girl refused to move. Transmission fluid all over the road. $2500 dollars later we are whole again with a better transmission and larger cooler.

Clay L · 02-10-2009, 07:56 AM

My owners manual says to turn the OD off if it's downshifting often. That only happens on stretches were the grade is changing a lot so it is on most of the time.

blacktie.shooter · 02-13-2009, 08:54 AM

Quote:

Originally posted by doc:
Consider adding another cooler to the transmission. The heat of the constant changing will get you.

Also consider changing your tranny to full synthetic. Heat is the #1 tranny killer.

When I changed out my Ford 7.5L, the engine temp hardly moved when climbing the same grade that caused a 30+ degree increase on fossil oil. I figured if I could do the same for the tranny, Mobil 1 was far cheaper than a new transmission, which, in this day and age, is a heck of a lot more than $2,500. Also, I'm adding a tranny temp gauge next time in the shop.

Another consideration: an acquaintance of mine tore out his O/D trying to tow with it on. At that time, it was a $1,000 bill and change to fix it, no idea what it would be now. Trust me, you will save NOthing in gas, certainly not enough to cover the repair bill.

millsrv · 03-10-2009, 09:34 PM

Hi, I have been a truck / auto mechanic for 30 + years. Simply put the trans should not be shifting up and down all of the time. If yours is constantly shifting in and out of OD you should down shift out of OD. OD should otherwise be used as much as possible. I always manually shift down if the trans starts to hunt back and forth or when the grade starts to change the engine load. I completely agree that heat is the number one enemy and installing a Trans Temp gauge is a great idea. Also Synthetic ATF is a good idea.