question do i suppose to drive in third or or d/od my friend mechanic says to drive in 3rd for better performance

 

Drive in OD unless your in a situation where it keeps shifting from 3rd to OD, OD to 3rd. (slow traffic, etc)

 

like slow traffic and city drivin red lights

 

hello

 

Yes thats what he said.

highway: OD
streets: 3rd

 

if youre roll racing id leave it in D. 1/4 mile racing i noticed no difference in times.

 

oh ok well imma keep it in regular drive then thanks for the advise

 

I would not put it into 3rd unless you had to. Putting it into 3rd brings on the overrun clutches in 1st and 3rd and robs the trans of 3-4 Clutch apply pressure. This will kill the 3-4 clutch pack over time. Just keep it in D (firebirds) or OD (camaro).

 

I disagree...

when the overrun clutch is applied, the forward clutch pack has approximately the same pressure (force) holding it applied...

the reason is the overrun clutch apply fluid pressure pushes in both directions on approximately the same sized surface areas, so the pressure/force contributed by the overrun clutch apply fluid on the overrun clutch piston (which assists holding the forward clutch pack) cancels out the pressure/force on the backside of the forward clutch piston (which opposes the forward clutch), leaving full forward clutch fluid pressure/force (on the front of the forward clutch piston) to hold the forward clutch pack.

-

 

BTW: in Manual 3rd, the overrun clutch is only applied in 3rd and not in 1st.

 

joecar is correct.

Leave it in OD unless you like being hard on your transmissions and are interested in working on your car more often.

Do you know if 3rd gear lock up is tuned out on your car?

 

Stop trying to be smarter then your car's computer Leave it in OD, and adjust your tuning to make your shifting suit your needs. I would only run in D or 3rd at the track if I was afraid it would shift into OD at WOT at the very end of the track, which I consider a no-no with such a fragile trans.

 

od it is then beside my car runs so smooth and hard in that gear any way plus its tuned for it

 

And of course driving in D3 will kill fuel economy as well, particularly if TCC lock-up is tuned out in D3 and/or you're running low rear axle gears.

 

Some points to be noted:
- if you can avoid bouncing between 3rd and 4th gears alot, the transmission can live longer;
- you want to avoid lugging the engine at low rpm in high gear for several reasons.

You may or may not get better MPG in 4th at low road speed... the problem is the engine is running outside of where it runs efficiently... at low road speed you may actually get better MPH in 3rd gear.

[ think about how you would drive an M6 Camaro: you would get to 4th gear (1:1) in city street driving, and you won't use 5th/6th (overdrives) until you're on the highway. ]

Of course, it is all personal preference/experience, each person can run in whichever gear they like

[ gasoline is cheap, the money saved won't pay for engine/trans repairs ]

 

I was talking about the 3/4 clutch pack, not the forward clutch pack. Not sure if that's what you meant.

Also what speed does the converter normally lock in D3?

 

so whats the final word?
in camaro:
OD is strictly highway or when you are traveling constant speeds ?
3 is streets with stop and go traffic ?
D is ?

 

Firebird has 3 where Camaro has D,
Firebird has D where Camaro has OD.

Firebird = P R N D 3 2 1
Camaro = P R N OD D 2 1

 

The overrun clutch is not stroking against the 3/4 clutch piston, so I don't see how it reduces it's holding ability.

In Manual 3rd the TCC locks as low as 26 mph.

 

D is 3rd.


Just use a forward gear and go, it's not that difficult.