I find that my 2001 GT shifts with much more certainty and much less lag if the Overdrive is turned off, but would driving around with it off all of the time do any damage or wear to anything?

 

Wait are you refering to when you hit your overdrive button the green light under you speedo says O/D off and revs up about 500 more or so?

 

Right. I figured it put less wear on the trans. but slightly more on the engine, but I wanted to clarify.

 

Theres no point in it...you use more gas.It's just not a good idea. If you want to shift better either get a tune or get a shift kit. I try and stay away from the O/D button but some ppl like to play with it. Only time I ever used the O/D button in my Explorer when I was towing my boat.

Theres a reason its not like that when you start the car.

 

Damnit. Oh well, back to the lumpy jumpy shifts I guess.

 

ehhhh shift kit or tune would fix that. But ignore that o/d its for the better. It is tempting to push though.

 

only use it if you're going from a roll on the highway.

 

That is also correct........past 35mph if I remember

 

actually, it's better to manual shift it from a 30 or 40 roll in second, and once you punch it just throw it into drive. but i dont street race :shifty: hehe

 

Shouldnt manual shift a Auto..........grrrrrrrr bad.

 

When the OD is engaged, the car will get into OD ASAP. The herky jerky you feel is the converter locking and unlocking. When its locked you have better gas mileage. Taking it out of OD will do nothing for performance. It will not hurt the tranny to drive with it off. Manual shifting will do nothing for performance, most likely hurts it(you will smack the limiter 99% of the time). Even if you leave the OD off, at a certain mph your car will shift into OD unless you have reprogrammed the PCM with SCT or some like flasher. Hope that clear up some of the wives tales.

Adam

 

ya with my sct tune, i was on the freeway and had the o/d off... and forgot to engage it back and hit 120+ and it was goin into redline :wallbash:

 

i leave my od off unless i am crusing above 50mph for a while. full throttle shifts into and out of OD are damaging to it

 

ya mine clunks hard

 

turning it off wont hurt it.... why do you think they give the option ???? :dots:

 

I started using OD off for pretty much all my driving after my tranny went. Less than a week after I got my car the transmission went on me. It got rebuilt through the dealer. When I got it back from him he told me that the guy at the transmission place said that I should leave the OD off unless I'm on the highway so I've stuck with that since then. Took me a while to get used to it at first but I have had no problems so far. It definitely does make the gas mileage worse though.

 

The increase in performance you think you feel is simply the line pressure being higher when manually shifted. Therefore it feels like its faster, quicker shifts etc. To the guy with the 98 that was told to leave his car out of OD unless on the highway, I would RUN from that tranny shop. My transmission has almost 130,000 miles on it, so I will keep on doing what I have always done... If you guys put 4:10's in your cars or steeper its pretty easy to leave OD on all the time.All I can tell you guys is even if you have a stock car, the 2 best things you can do for your transmission are J-Mod it and put on a tranny cooler, you can do both for less than $75 and you will virtually bullet proof it unless you start laying down some mad (350rwhp+) the 4R70W is a great transmission. 96/97 are not quite up to the 98, and the 99 newer are even more superior (bigger holes in the seperator plate for increased fluid flow) good luck with whatever route you take.


Adam

 

What's J-MOD?

 

go to www.tccoa.com look under drivetrain in the tech articles.

Its a shift kit that was invented by Jerry Wroblewski, SCT tuner extroadinare and one of the original designers of the 4R70W tranny. Its an excellent mod and firms up shifts.

Adam