Why shouldn't I get on it in OD?
I'd recommend at least a billet overdrive servo. Factory, 4th gear (overdrive) is NOT meant for such abuse. Now and then, sure, but if you do this a lot expect your trans to say bye bye.
I killed my last trans doing just that. It was so-so slipping a VERY little bit, then one night at 3am on an open highway I decided to put the hammer down. At 144mph I banged the limiter HARD, and never had 3rd or 4th again. That should give you a clue how hard that is on the trans. Went from a VERY slight flare to smoked in 10 seconds due to the added stress.
And it's not just the shift, it's the holding power required. In Overdrive, you're just that. 4th gear is overdriven, meaning the input side is at a mechanical disadvantage. The 3/4's are in the input drum, so to "push" the car in 4th they have to push the car MUCH harder than in third, where the drive ratio is 1:1. Also the additional wind force is a major factor.
OD is mainly just for cruising, where there is little load placed on the engine/trans.
And like Colonel said, 4-2 shifts are much harder than 3-2 shifts on the trans.
"D" range also applies the overrun clutches, taking a load off of your sprags.
Trending Topics
The Best V8 Stories One Small Block at Time
I'd like to hear more about this as well. I hear different stories from different builders all the time.....
Don't you hate that
As far as I know, just don't get on it ever
But what I can gather from this thread is. Race is D or 3. And don't mash the gas while in OD or 4th because it is stressful on the tranny to go from 4-2, but 3-2 is ok
Anyone know when 4th kicks in for a 2.73 geared car? I am thinking between 40 and 50 it kicks in most of the time
Lumbering around town doing 25-35 mph in OD is kinda hard on the bottom end. Yes, the tranny will shift down when needed but I still think idling around town in OD is not too good on the motor or tranny. IMHO that is. Take it with a grain of salt.







