: Overdrive and Heavy Loads

DopeStar 156
07-16-07, 05:13 PM
Ms. DS and I are headed to the shore tomorrow for 9 days and of course there's only one car I'd want to have on a sunny beach trip, my Fleetwood. She's all set to go, tire pressure's 32 all around, oil level is topped off, gas tank is full, new springs and level ride are fully functioning. :D

However, with a trunk full of beach stuff and enough luggage for two fashionably conscious individuals for 9 days, would anyone reccomend the 100 mile drive without the O/D? I'll most likely have the cruise set to 65 the whole trip......

Lemme know!

07-17-07, 01:21 AM
I would use overdrive, then when you get to a hilly area where the tranny is going back and foward between 3rd and 4th drop it down in 3.

07-17-07, 07:09 AM
Overdrive is typically not a "gear" it is a band applied to one of the drums. For your trip it is not a big deal to use OD. For towing or really heavy loads I would suggest keeping it out of OD to ensure that the band is not overheated. Usually the OD band lining is fairly thin material.

07-17-07, 07:12 AM
Overdrive is typically not a "gear", it is a band that applies around one of the drums. Pressure to apply the band comes from the OD servo which is first activated by hydraulic fluid pressure. For your trip, using OD is not a problem, but for really heavy loads, towing I would suggest keeping it out of OD. Problem is that the OD band lining is fairly thin and can be overheated by heavy loading.

07-17-07, 07:16 AM

07-17-07, 11:46 AM
hmm im usually pretty hard on my OD going up hills and such. i wonder if thats a problem. i dont put heavy loads in my car very much but when im on the freeway at 60 +/- i dont like it to shift out so i need to practically floor it up hills without it shifting out to keep my speed.

Cadillac Giovanni
07-17-07, 09:54 PM
At the risk of sounding like a total moron, how do you engage the overdrive?

07-17-07, 11:09 PM
Just put it in D. And count the shifts. When you get on the interstate you should feel what seems like 5 gears.
4th OD
then the torque converter locks up.

Cadillac Giovanni
07-17-07, 11:26 PM
i figured it had to be some automatic thing i was missing. I keep hearing about it like it's something i can engage and disengage at will, like i can on most other vehicles i've driven.

07-18-07, 12:03 AM
Running in 3rd will reduce trans life though, as overrun clutch/sprag is locked and whenever back off the gas, the overrun clutch stays locked up, and causes it to be loaded all the time, causing additional trans wear. This is one of the main parts that wears in the modern auto slush box.

With the lazy 2.56's many of the 307's got (hopefully you have 2.73's at least) you won't hurt the engine at all, and probably won't even hurt mpg much. You can run 100 mph with no ill effects in D, so don't worry at all about rpms.

If it starts getting shift happy or hunting, then by all means, give it some gas, wait till it downshifts to 3rd and then move shifter down. NEVER ever pull the shifter down to 3rd while you are in OD and not on the gas at a minimum, but it is best to let the trans do the shift and then you shift and lock it to that gear. When you pull it down, especially while you are decelerating is very hard on the overrun clutch as it has to suddenly get loaded up and take all the power that the car is about to give it. It is not nice to it.

I have heard that for every manually shifted shift is one less upshift in the life of the trans...

Enjoy the trip with the Ms!

DopeStar 156
07-18-07, 07:06 PM
I used the D gear all the way here. It seemed fine, nothing but smooth sailing. Thanks....