Why shouldn't I get on it in OD?
 

I've heard that it isn't good for the 4l60e to rip around in OD. Why is this. Should I just put it in D? Why? Will the car go into 4th if it's in D on say the highway? I just need some clarification on this. Thanks.

Driving in OD is fine. Who comes up with stuff like this. (you say you heard) The shifter has to be in OD for the tranny to shift to 4th. As soon as you get on it, it is going to downshift anyway.

It's fine to drive or kill it with the selector in OD. Just don't do let the tranny shift into 4th at WOT if you expect good clutch life. That's pretty hard on the 3-4 clutchpack in my experience.

Colonel, how about if you are racing up to 150? When it comes time to shift to 4th, what should I do, let off the gas a little then when it shifts to 4th, go WOT?

Well, I don't know why one would want to race up to 150. By then the winner SHOULD be pretty clear. But if you must (and I hope you do it in very remote areas).....

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.

So it's fine to hammer it in OD as long as you don't stay on it through 4th. I'm talking about if I'm doing 30 or 50 mph in OD and hit it. Is this okay then?

the trans will shift from 4-2 depending on which end of the 30-50 range you are in.

So if am reading this right you should do most of your racing in D instead of OD to keep wear down?

Back up....

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 :guns:
As far as I know, just don't get on it ever :emb: :barf:

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 :drive:

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

What speed does OD kick in???

with my 3.42's at about 40mph the OD lockup engages dropping the engine a hair over 1000rpm's.

so i'd guess its ring around there. Hard to feel the shifts with a verter and loud exhaust

Anymore opinions on this one?

So from what am gathering when racing put it in 3 so you don't shift in or out of OD casue it's hard on the tranny. When am driving at low speeds I usally keep it in 3 anyways.

The only issue with this is, if you're already in OD while cruising and something comes up where you're gonna go WOT, should you first manually shift back to 3rd, wait a moment while the trans responds and goes back to third, and then go WOT? I try to always avoid manually up/down shifting my A4s, but is it OK to go back just to 3rd (under zero throttle) before hitting it from a roll?

Very good question that always seems debateable. When racing at the track "drive" or "overdrive"? does anyone have suifficent info or any way to prove on is better than the other.

The only time I click it into OD is when I get on a freeway.

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.

i heard you want to put it in d because when you let off the gas everything goes from high rpm's to nothing and shakes everything around and 3 just helps you stop also!!

It isn't hard on the tranny manually shifting from D to OD like going from city to highway is it as long as you aren't in the gas? I guess I need to drive around in D according to this post, kind of confusing!

All I need to know as well. Should we be doing this? Also, What if you are in OD, drop the hammer and let it downshift, run up to about 80-90 MPH, then let out, would the trans not shift back into OD? Is that OK after you've let off the gas, or is there still that pressure on the clutches in the trans?