Just a quick question about my '90 CC's tranny. With a 200-4R is there any problem with leaving it in D when you're not going to exceed 50MPH for the whole trip? I know you lose some MPG but all we drive here on the Kitsap Peninsula is windy 45MPH roads so it is a pain having to go in and out of overdrive constantly, especially on the hills. On the freeway we put it in OD. My rebuilder had eluded to this when we rebuilt it a year ago but the manual says you can leave it in OD. Same with my 700R4 in my '91 CC.

Thanks.

 

At those speeds I don't see how it could hurt anything as long as the converter locks into direct drive. You'll lose a little gas mileage is all.

Ford for all their idiot **** solved it elegantly. Push a button in the end of the shift lever to turn off OD. I rarely drive with it turned off but about once a month I do it to make sure it functions. Same time as I test the 4WD on the trucks.

 

The transmission is smarter than you are, it knows what gear it needs to be in. The only reason you would want to leave it in drive is if the trans is constantly upshifting/downshifting.

 

It just takes a lot of effort to drop out of 4th on the hills.

 

I do this all the time with my daily driver 93 full size blazer. OD with the 3.73s lug the low horsepower 350 down to much. I don't use OD until 55. 50 in drive is 1900 rpm, 50 in OD is 1400. Believe it or not i see no change in mileage and it drives much better. I live in a rather mountainous area and was tired of the gear hunting..

Edit- the blazer has a 700r4

 

That's what I was thinking too. If I don't get it out of OD before a big hill I'll have to floor it to drop it out of OD and then slog up the hill.

 

GM liked these cars to stay in OD for as long as possible. A lot of times the trans will hold OD so long that when it finally does downshift it'll have to go down to second to regain the speed. Had it been in drive it would have not needed to downshift.