jordanray

not to sound so ****ing stupid but i am sort of ignorant of it, obviously. what exactly IS the o/d?

and is it true that if you start the truck in first gear than D (automatic tranny), that it'll take off faster?

one last thing. when it is in D and you're driving around and you come to a stop, what gear does the truck normally take off in? cause honestly, seems like mine most of the time is in second gear when it takes off

Buckstruck

Great question! sorry I can't help.But I have to add to it. When should you turn o.d off? when you have heavy load?

Ranger2F150

I'm not trying to be nasty....but don't you guys read your owners manaul? It will explain this.

wde3477

Some of the older Ford automatic transmissions did have a feature that allowed starting off in 2nd gear if the selector was placed appropriately. Perhaps your selector indicator is not aligned properly, or you have a problem in the tranny.

When in 'D', the tranny should start off in 1st gear.

O/D for an automatic tranny in most cases means that the torque converter locks up. It is advised to override O/D when towing or hauling a heavy load, or in extremely hilly conditions.

atompkins99

When your transmission is in low gear, the engine crankshaft must make several revolutions in order for the driveshaft to make one revolution. As you shift up through the gears the ratio becomes smaller. In a typical transmission top gear gives you a ratio of 1:1. Overdrive means you have a gear where the engine crankshaft turns less than one revolution for each revolution of the driveshaft.

kc5gxl

Hello Jordanray;

The o/d simply means that in the highest road gear, usually 4th gear, the output shaft of the transmission moves faster than the input shaft. In other words, in 'over-drive'.

When vehicles equipped with an automatic transmission comes to a stop, the gearing will 'automatically' down shift to 1st gear, which is the same gear ratio as manual 1st. One of the main differences between the two are internal. That is, the way the the internal components are held.

The other main difference is how long the trans stays in first gear. In O/D or D(3), the trans will automatically shift into the next gear as the output shaft speeds up, to keep the engine from over revving. In manual low, (1), the trans will not upshift, but stay in 1st gear.

If your trans is not downshifting all the way to 1st gear, then there is something amiss, and it should be checked out. It may be something simple like a misadjusted pointer, or could be fairly serious. Personnally, I have driven vehicles with automatics in them that wouldn't completely downshift to 1st, but by simply moving the selector to 1st, then back to O/D or D when at a stop, it will start and shift normally.

Hope that helps some,

Dan Harriman
Orange, Texas

Dark Stone

To Buck's question, when should you turn it off. Usually you will hear the rule of thumb that you should turn it off when ever you are towing or hauling a load. I usually leave it on even when towing as long as the truck isn't cycling in and out of O/D (changing gears) when I'm running along at speed.

John

kc5gxl

I do the same thing John. If it is not cycling in and out of O/D, then it isn't laboring too much to ruin the trans. If you have a trans temp gauge, then if the temp goes significantly above normal, then P/D should be turned off.

Dan Harriman
Orange, Texas

jordanray

hmm. so say IF i was racing...would i turn o/d off?
i've also heard that it's best to put it to first then second myself while racing.

and really it just seems like it takes off in second still, who knows. because even at times after i come to a stop, if i put it to first myself i feel the shift change.

and to the first replier, i would read my manual but i get lost in it and find it easier to just ask here, sorry

i'm fairly new to...automechanics but am trying to get in it. i have another question but i guess i should start a new topic for it since it's far away from the tranny and such

Mod (Ret.)

Yes IF you were to race (and please, not on public streets), leave the overdrive off. And I just don't understand how you can get lost reading an owners manual. I opened mine up after reading this post, and it is quite to the point as to when the O/D (that's over drive) should be used, and when to turn it off (by pressing the button on the end of the gear selector (at least it is on my 2005 model). Sad, very sad.

I see you are new to the forum, as I am too. Do not take my answer the wrong way, as that of the others that post here too. But to get a decent understanding about automechanics, you will need to pick up some books and read. You will need to purchase a good repair manual and read. Being able to understand the workings and repair any auto made today requires reading, asking questions, and a good set of tools. Mearly posting a question on any forum will not gain you the knowledge you may desire, even if you think it's easier to do it that way. No offense. No one here is trying to deliberatly poke at you. If you are having difficulty understanding an owners manual, you are going to have a tough time grasping "automechanics". Can't make that part any simpler.

As to the racing comment; I pray that you are not refering to the public streets. They are meant for public transportation. Not for idiots who think street racing is cool. Just recently, a 4.3 grade point average high school girl lost her life last year to a driver who raced another out of the high school parking lot onto a public street, and continued the race. This innocent girl was walking to her car; she never saw what came at her; she never had a chance. He did not stop. He did not even know he hit (and killed) her. The police caught up with him later after half of the parking lot witnessed the whole event.
This idiot is still out on the road, and driving. Apparently his family has money and is fighting the vehicular manslaughter charges in court.

To the moderators, I'm sorry to have posted this response; but if it prevents someone from "racing" on the street and saving a life, it is worth the scolding I may receive. In the future, I will refrain from posting to these sorts of questions.