.. ok so my truck has the 4 speed tranny in it. It also says it has overdrive... now does this mean that 4th gear is o/d or does it actually have a 5th gear that is considered overdrive?

I guess it holds true... An aircraft mechanic works on million dollar aircraft's but can't fix his $150 lawnmower (or truck).

 

It means your 4th gear is an overdrive.

 

that's what i was thinking but i swear i can hear/feel 4 shift points which is why i was wondering if O/D was a 5th gear

 

O/D isn't a 5th but it's a different gear ratio than 4th, i don't really know all the details but if you want to know more there are people here that can help.

 

Hello.

4-speed auto: 4th gear IS OD. 3rd is a 1:1 ratio; 4th is 'overdriven' , a fractional ratio. like 0.67:1 - see yer owners manual for the exact ratio,

What you are feeling is the torque converter locking/unlocking - feels like a shift. Happens under certain TP positions/loads/road speeds/gear.

MGD v5.0

EDIT - corrected '2rd' to '3rd', lol

 

MGD is right. With my custom tune people always say "Wow, your truck takes a long time to shift into overdrive." Nope, it shifts into 4th around 40 mph and the torque converter locks at 50ish.

 

glad i got that out of the way... thanks for all the help and explanation!

 

No.

OD is 4th gear. It is a 0.7:1 ratio. You feel four shifts, 1-2, 2-3, and 3-4. The fourth shift that you feel is the torque converter lockup clutch engaging. That eliminates slip in the torque converter. It is not a different gear.

There is a lot more information on how this works at www.howstuffworks.com.