The Stovebolt Site Forums The Shop Area Driveline Just landed an overdrive trans

Cosmo;

Sent you a PM. I need pictures.

question I'd have is why you'd want to use overdrive in any other than 3rd gear?

Bill

The only time I go into overdrive in second is if I am driving short stretches below 40 mph, such as a short stretch in town between the highway into and the highway out of town or on the mile up hill on the country lane going to the house. On the highway I never go into OD until I hit cruising speed in third. If I'm doing sustained driving in the city or out cruising county roads I disable OD with the cable.

If you are in second OD there is no need to come out of OD to go to third.

Driving report:

After I topped off the trans with 50 weight motor oil like Charlie said to I went out for a deliberate test drive.

I find that it would be nice to be able to go into 3rd under during acceleration. It's nice to have 2nd over for building speed but the jump between 2nd over and 3rd over is too high to be convenient. I'd like to be able to go from 2nd over to 3rd under. I'll see what Cosmo has for recommendations/pictures for the switch setup.

The only issue that I see right now is that I don't seem to get the free wheel function at speed when the overdrive is engaged. With the OD in the on position and I'm driving in 1st gear the free wheel works. If I let off the gas is just coasts at idle. When I get into 2nd or 3rd with the overdrive engaged the free wheel doesn't work. Going down hill the truck will roll along but the RPMs stay steady at speed. I thought they would drop to idle until I got back in the gas to pick up speed again. Is this normal or a problem. It doesn't really affect the driveability, its just a feature that I thought would work.

Anyway, very happy with the set up. Makes for an entirely different driving experience. Lots of fun.

Sounds like it's working normally. The freewheel function only works at speeds under 28 mph, which is the speed that the governor makes/breaks contact. That is also why the overdrive will not engage in first gear, you have to be going over 28 mph to engage the overdrive.

Like Bill just said, freewheel does not work when in OD only direct.

Gentlemen;

Hooah. Thanks. I guess I misread the literature.

I'll close out this thread.

Thanks for all the help.

Follow up post.

Based on some advice from Cosmo, I decided to install a toggle switch for the trans. I left the dash mounted kickdown switch in place so that I could punch that to temporarily downshift when driving on the highway and going up a big hill. I like the idea of a one-time downshift and then going back into overdrive.

With the toggle switch, I can deactivate the overdrive function without having to push the cable in. It's a pain to push the cable in and out.

I went out for a test drive and it works great. One interesting thing is that with the cable in the overdrive position and the toggle switch turned off, the freewheel function works in all three gears regardless of speed. That is cool for when I get into town and want to disable the overdrive. Its kind of the best of both worlds.