Gears

**paperman40** · 08-11-2010, 07:43 PM

How do find out what rear end gear is in my 1999 TA

**Y2KPewterSS** · 08-11-2010, 08:12 PM

Look at your RPO codes on the driver side door.

GU2=2.73

GU5=3.23

GU6=3.42

Any LS1+manual tranny has 3.42 gears. All SS/Firehawk/WS6+auto trannies came with 3:23s. Z28s/Trans Ams came with 2.73s and an option for 3.23s.

**paperman40** · 08-11-2010, 11:35 PM

Thanks...

**paperman40** · 08-11-2010, 11:41 PM

I am pulling 2300RPM at 70MPH is that high for a 3.23 gear, what do you guys think

**paperman40** · 08-11-2010, 11:43 PM

And I just got the car last week.. The door code is GU5...

**RedHot99T/A** · 08-12-2010, 11:48 AM

in 6th gear?if so yea im around 1500rpm,u pry have a higher gear in her for sure if thats in 6th gear unless its an auto?

**Ant71130** · 08-12-2010, 06:30 PM

Originally Posted by paperman40

I am pulling 2300RPM at 70MPH is that high for a 3.23 gear, what do you guys think

In what gear? That matters a lot. And yeah, auto or manual? I got 4.10's in my M6 and I'm not even at 2,300rpm @ 80mph. Like 2050 or 2100 tops.

**67CamaroRSSS** · 08-12-2010, 06:34 PM

Originally Posted by Y2KPewterSS

Look at your RPO codes on the driver side door.

GU2=2.73

GU5=3.23

GU6=3.42

Any LS1+manual tranny has 3.42 gears. All SS/Firehawk/WS6+auto trannies came with 3:23s. Z28s/Trans Ams came with 2.73s and an option for 3.23s.

^^^^^ What he said...

Hi P!

**paperman40** · 08-13-2010, 01:49 PM

Hi guys, sorry it is a auto

**Too Fast** · 08-13-2010, 02:48 PM

Originally Posted by paperman40

I am pulling 2300RPM at 70MPH is that high for a 3.23 gear, what do you guys think

That's right for a 3.23. Not high RPM at all, considering cars before overdrive transmissions with relatively low gearing of 3.55s would be running around 2850 RPM at 60 MPH. 3.73s or higher would be even worse! I'm trying to figure out what gears to put in my '68 Le Mans ragtop, it currently has 2.52 gears with a 2(!) speed tranny. Wondering if I should put an OD trans in it or not.

**67CamaroRSSS** · 08-13-2010, 03:27 PM

Originally Posted by paperman40

Hi guys, sorry it is a auto

If it's unmolested then it'll be either 2.73's or 3.23's. Check the door codes and compare with Preston's post (Y2KPewterSS).

You can also check the driveshaft. Steel was used on 2.73 geared cars while aluminum was used on 3.23 geared cars.

**travs98ls1** · 08-13-2010, 05:07 PM

Originally Posted by Ant71130

In what gear? That matters a lot. And yeah, auto or manual? I got 4.10's in my M6 and I'm not even at 2,300rpm @ 80mph. Like 2050 or 2100 tops.

Originally Posted by 67CamaroRSSS

If it's unmolested then it'll be either 2.73's or 3.23's. Check the door codes and compare with Preston's post (Y2KPewterSS).

You can also check the driveshaft. Steel was used on 2.73 geared cars while aluminum was used on 3.23 geared cars.

Mine is a GU2 auto 2.73's its around 2050 to 2100 rpm at 80mph! lol hence my 26 mpg on the freeway only its getting around 375 mi or so per tank, was cheaper than a rental plus gas from san diego ca to my hometown in black hills south dakota. had the ole lady then so had to fight the temptation to open er' up on the long empty highways hehe!!!

**travs98ls1** · 08-13-2010, 05:12 PM

Originally Posted by travs98ls1

Mine is a GU2 auto 2.73's its around 2050 to 2100 rpm at 80mph! lol hence my 26 mpg on the freeway only its getting around 375 mi or so per tank, was cheaper than a rental plus gas from san diego ca to my hometown in black hills south dakota. had the ole lady then so had to fight the temptation to open er' up on the long empty highways hehe!!!

next time leave the ole lady home! and score some silver state classic driving

4600 rpm in overdrive shes at 145-150 mph havent gone further...

**Ant71130** · 08-13-2010, 06:57 PM

Well, my comment was referring to 6th gear, I'm assuming people generally reference 4th 'cause of 1:1 :P.

If you're really curious and assume it's not stock or was altered, do what I did. Went down to a shop, told them I was curious on something and asked if they'd help me real quick with letting me use their lift. Lift it up, mark the wheels and have both sides pointing down, mark the drive shaft and a stationary part next to it to be considered "0" and have a couple guys rotate the wheels at the same time one full revolution and count how many times the shaft turned. Or rotate one and double the number (easier the former way as decimals can get too close for eye)

**paperman40** · 08-14-2010, 04:24 AM

Thanks Everybody For the Help....Paperman40

**RyanJM** · 08-17-2010, 12:21 AM

I have a 3.23 A4 and after chewing them up I swapped in Motive 3.73's. There fine and very slight loss of mileage on the highway compared to the 3.23 but better launch and pull harder on roll and dig runs againt 6spds. Especially with a good tranny tune and raise the shift points to 6k in every gear and it is like a new faster car even though the hp is the same.