Driveing in overdrive?

Transmissions like ours do not have five speeds. They're basically the venerable (and legendarily tough) C-6 three speed with an overdrive gear, and then an electronically controlled valve body, added. All our "OD Off" button does is limit the transmission to three speeds with converter lockup. The newer 5R110 (popularly known as TorqShift) has more gear ratios available. It picks among them and doesn't use all at once. It OD ratio is same as ours. The big difference is the Button is now "Tow/Haul" and it re-programs the transmission. OD is still possible, but lots of things happen behind the scenes. It also downshifts when you brake, to help control speed on downgrades.

Welcome! You'll be helping others soon enough.

j-d wrote:
We're in FL with a 31-ft C V10/4R100. E4OD means you probably have a V8/460 engine. Ford morphed the E4OD into the 4R100 with minimal changes when they went to V10 in 1997.

We run in OD which is Fourth Gear, Locked Torque Converter. At the slightest additional load, like an overpass on the interstate, it downshifts. When that series downshifts, it doesn't just unlock the Converter to produce a little more torque to the wheels. Instead, it drops to Third Gear, Locked Converter. Basically, goes to Passing Gear. That's quite a ruckus but how the transmission is designed.

It's most sensitive when on Cruise Control. If I see an upgrade, I can speed up by enough that the "sag" caused by the climb is no more than about 1-mph less than the cruise is set for. Otherwise it's gonna downshift.

In hilly country, like FL Panhandle, I leave it in OD but don't use cruise. It's less annoying to me to see a grade, speed up, let the speed sag, recover it on the downhill, repeat for the next grade.

Nature of the Beast, hope this helps.

Absolutely, This is my first RV and overdrive transmission so I'm still getting used to it. The first time I took it out after bringing it home, I was sure something was wrong with the tranny cause It shifted at high revs and I couldn't get fifth gear. Then I noticed the overdrive button and it started shifting nicely after I pushed it. Thanks to eveyone for the help. This forum is the greatest!!!

We're in FL with a 31-ft C V10/4R100. E4OD means you probably have a V8/460 engine. Ford morphed the E4OD into the 4R100 with minimal changes when they went to V10 in 1997.

We run in OD which is Fourth Gear, Locked Torque Converter. At the slightest additional load, like an overpass on the interstate, it downshifts. When that series downshifts, it doesn't just unlock the Converter to produce a little more torque to the wheels. Instead, it drops to Third Gear, Locked Converter. Basically, goes to Passing Gear. That's quite a ruckus but how the transmission is designed.

It's most sensitive when on Cruise Control. If I see an upgrade, I can speed up by enough that the "sag" caused by the climb is no more than about 1-mph less than the cruise is set for. Otherwise it's gonna downshift.

In hilly country, like FL Panhandle, I leave it in OD but don't use cruise. It's less annoying to me to see a grade, speed up, let the speed sag, recover it on the downhill, repeat for the next grade.

Nature of the Beast, hope this helps.

The vehicle is geared to work with that transmission so let it do it's thing. Going up a hill it will downshift when appropriate but there's no issue with being proactive and downshifting to keep the rpm's up or when the transmission is hunting between gears too much.

The slower the motor the higher the MPG. You can tell when you need to kick it out of OD. I have a class C diesel and never take mine out of OD except when I am in the mountains or descending a long hill. Camp on.

Hi,

I switch out of overdrive when descending from mountain passes.

I use OVERDRIVE with my towing usually when on the INTERSTATE for long non-hills driving. I can tell by watching my RPMs if the engine is in any strain and will switch out when needed... Not really sure I get any savings in fuel consumption or not.