Hi all--basic question about driving our Roadtrek. New to us 1997 170P with auto trans. We are in the mountains of Pennsylvania for the summer. Question is should I manually drop the trans in to second gear from drive when decending a long grade? My question centers on whether it is better to wear out the brake or put extra strain on the trans when going down a long grade. Going up, the trans automatically shifts to a lower gear to climb, but that is not the case going downhill. Engine braking is not enough to keep the speed down and I find myself braking too much. Our RT has had the transmission replaced once already in its history and I would like to preserve the new one for as long as I can. What do you think--brake or transmission??

Both is what I use on my 1977 Dodge B Van conversion. You could have a Trans Temp Sensor put on to help you know how it's working...

Thanks Corvetteken--that is what I have been doing. Just wondered if it the best thing overall.

Have you flushed the brake fluid? Brake fluid absorbs moisture and should be flushed every 2-3 years.

Yes go down a gear and hold RPM close to 3500 when descending a longish grade. Avoid gear hunting especially near full throttle for longest transmission life. And don't ride the brakes when needed. Use the brakes to slow a solid 10 to 25 mph and then let it coast back up to speed. Drive slower in general. Let the monster diesels run at or above the speed limit.F150 original trans holding well at 190,000 miles. Fluid service every 30,000.

Brakes or transmission?? | Good Sam Community

Traveler7
Explorer
Apr 25, 2016
Both is what I use on my 1977 Dodge B Van conversion. You could have a Trans Temp Sensor put on to help you know how it's working...
corvettekent
Explorer
Apr 25, 2016
Shift down one gear.
chast
Explorer II
Apr 25, 2016
Thanks Corvetteken--that is what I have been doing. Just wondered if it the best thing overall.
bsinmich
Explorer
Apr 26, 2016
Have you flushed the brake fluid? Brake fluid absorbs moisture and should be flushed every 2-3 years.
time2roll
Nomad
Apr 26, 2016
Yes go down a gear and hold RPM close to 3500 when descending a longish grade. Avoid gear hunting especially near full throttle for longest transmission life. And don't ride the brakes when needed. Use the brakes to slow a solid 10 to 25 mph and then let it coast back up to speed. Drive slower in general. Let the monster diesels run at or above the speed limit.

F150 original trans holding well at 190,000 miles. Fluid service every 30,000.
Terryallan
Explorer II
Apr 26, 2016
Me. I use what ever gear it takes to hold the speed I want. Often coming down from the Blue Ridge, That is first gear. then I can shift to 2nd as we get down to the less steep, and less twisty sections. General rule is to use the same gear coming down you use going up. But if you need more, drop another.

Also even thought you may worry about your tranny. Using it will not only save your brakes, but may save your life. IF you heat the brakes too much coming down. You lose them all together, and then it will be too late to gear down. You will just be along for the ride. So for safety. Use the trany. I can come 321 from Blowing Roch, and down 16 from Glendale Springs, and hardly use the brakes.
DownTheAvenue
Explorer
Apr 26, 2016
Brakes are cheaper than transmissions.
KD4UPL
Explorer
Apr 26, 2016
Downshift as much as necessary. Brakes are plan B.
Terryallan
Explorer II
Apr 26, 2016
DownTheAvenue wrote:
Brakes are cheaper than transmissions.

Ask yourself that question again, after you have burnt your brakes up, and glazed them going down a long steep grade. Lots of time to find the answer as you go over the side, or dive into the runaway ramp.
ryegatevt
Explorer II
Apr 26, 2016
Terryallan wrote:
DownTheAvenue wrote:
Brakes are cheaper than transmissions.

Ask yourself that question again, after you have burnt your brakes up, and glazed them going down a long steep grade. Lots of time to find the answer as you go over the side, or dive into the runaway ramp.

Ditto!