First, a comment. I listen to Car Talk on my way to teach an ESL class which means I hear only about 25 minutes. The first Sat. in Dec. I heard one of you say “the oil begins to break down” which I disagree with. When I worked for the Santa Clara County Transit system I learned that oil never loses its lubricity. It just gets dirty and that’s why we can buy recycled oil.//I bought a '90 Montero in '03 from the original owner with just over 27K miles. I had the transmission service by a transmission specialist at 37,760 who told me the transmission is built by Toyota and that it doesn’t contain a filter. I had it serviced again at 73,686 miles. Question: Does the transmission contain an inclineometer? I ask because in cold weather on my way home from school I have a long downhill run and it will downshift out of overdrive every time unless I continually tap the brake or accelerate slightly. Even if I do this there is a slight incline next and it will downshift when I start up that small rise. It causes my gas mileage to drop 2 mpg very winter. I have driven the 3 miles from a traffic light to where I leave the highway to come up the hill and it hadn’t shifted back to OD.
Many transmissions exibit this in/out of OD both going up and down hills,most people are given advice to stay out of OD on hills.
The oil info is ages old,nothing new,point is made during every discussion about oil.
Elaborate on this inclineometer device you seek,are you asking if there is a sensor that tells the transmission what angle the truck is at? (I had a Rover 88 that had a bubble level in it,told you how much you were leaning, I think it was the only option)