rear end

**lancesT/A** · 05-28-2007, 08:15 PM

first of all what is my stock rear end i thought it was 3.42's but i could be wrong, anyways how much of a difference would i notice by putting in 3.73's? my car is a 97ws6 a4 with full exhaust, cam and hypertech tune.

**rocksws6** · 05-29-2007, 09:02 AM

I think I would run 4.10's seeing as how you have the A4. I think it would get you out of the hole a whole lot better. 3.73's would be better suited for a manual.

**2000T/A Guru** · 05-29-2007, 09:27 AM

Actually you have that backwards 3.73 is better for auto because you only have 4 gears if you had 4.10s you would be at 3000rpms at like 50 miles per hour just driving. About the difference i noticed alot in my auto car but thats just because i was goin from 2.73s to 3.73s lol.

**lancesT/A** · 05-29-2007, 09:53 AM

thanks i know that i dont want 4.10's because to me that my car out of the daily driver realm. hey guru how much did you pay to get your gears changed or did you do it yourself.

**2000T/A Guru** · 05-29-2007, 09:59 AM

Did it myself

**lancesT/A** · 05-29-2007, 12:43 PM

was it hard or do you have alot of experience doing it, i am comfortable with engine work but drivetrain stuff i am a little sketchy about

**2000T/A Guru** · 05-29-2007, 12:47 PM

If you get install kit its pretty easy

98T/Aformula · 05-29-2007, 01:09 PM

I have a 98 formula a4 and it had 3.42s and I went to 3.73s and I got an install kit as well and it ended up costing me about 220 for the install, it really woke the car up for sure, I went with Motive gears and the only wine I get from them is at about 55 ta 65 but only you will notice it. I would get them, I was very hesitent at first but now I would recomend them, then a set of DRs so you can stick to the ground better and you will notice your car taking off of the line like a bat out of hell.

**TACE02** · 05-30-2007, 06:43 AM

I thought A4's came with 2.73 or 3.23 depending on which option you picked, WS6 being 3.23. But yeah definately go with 3.73 with an auto, GM makes some of the better gears out there and have no whine. And they are cheaper.

**2000T/A Guru** · 05-30-2007, 06:47 AM

I heard most fmrulas came with 2.73s so they would look slower off the line then Trans Ams.

**rocksws6** · 05-30-2007, 09:35 AM

Damn 2.73's that's a pretty high gear. What does the WS-6 M6 come with? I'm kinda new to this whole f-body deal. I've only had my car for about a week and a half now so excuse my ignorance. But I know in the hemi ram most people were running 4.56's, hell they come with a 3.92's. I would think 3.73's for an automatic would be a little conservative. What's the OD ratio for the A4?

**john5632** · 05-30-2007, 01:31 PM

Originally Posted by 2000T/A Guru

I heard most fmrulas came with 2.73s so they would look slower off the line then Trans Ams.

I have a formula,but mine came with 3:23 gears.Im looking to step up and Im going with 3:37 gears with my 3500stall

**lancesT/A** · 05-30-2007, 03:03 PM

Originally Posted by TACE02

I thought A4's came with 2.73 or 3.23 depending on which option you picked, WS6 being 3.23. But yeah definately go with 3.73 with an auto, GM makes some of the better gears out there and have no whine. And they are cheaper.

i said i thought 3.42's but i wasnt sure but if what you are saying is true then i will feel a real difference. i already ordered the gears they are the gm brand they should be here next week, i plan on installing them myself. thanks for all the info everybody.

**SteveC** · 05-30-2007, 03:49 PM

I have never read so much mis information in my life. First of all, LS1 Camaro's and Firebirds with the A4 option came stock with 2.73's (GU2), when you purchased the Z rated tire option (QLC) the optional 3.23 (GU5) was added along with an aluminum drive shaft. The V6 Camaro 3800 engine A4 option came stock with 3.42's (GU6).

The best rearend gear option for the A4 is 3.73's, the problem being with 4.10's is that if you kick down hard on the freeway in OD, the transmission MIGHT down shift into 2nd gear, which would through you over the redline.

The difference between 3.23's and 3.73's is only 500 RPM, what makes a BIG difference is when it is coupled to a performance converter, the lower gear ratio gives you a quicker spool up, and raises the RPM shift extension. My Y3000 shift extension is 4200 RPM @ WOT.

I coupled my 3.73's to a Y3000 2.0 STR, and the vehicle is far more responsive. If I had to do it all over again I would go a minimum of 3200 up to 3600 on the stall.

SteveC

**TACE02** · 05-30-2007, 04:37 PM

Originally Posted by rocksws6

Damn 2.73's that's a pretty high gear. What does the WS-6 M6 come with? I'm kinda new to this whole f-body deal. I've only had my car for about a week and a half now so excuse my ignorance. But I know in the hemi ram most people were running 4.56's, hell they come with a 3.92's. I would think 3.73's for an automatic would be a little conservative. What's the OD ratio for the A4?

You my friend should have 3.42s for gears. If you wanna upgrade. 4.11s are the difference maker in the M6.

Glad my info isn't misleading

**lancesT/A** · 05-30-2007, 05:34 PM

i know ya'll are all ls1 people but remember my ws6 is a lt1 and i am pretty sure i have atleast 3.23's not 2.73's either way come next week i will have 3.73's and then i wont ever be left wondering.

**SteveC** · 05-31-2007, 07:07 AM

Originally Posted by lancesT/A

i know ya'll are all ls1 people but remember my ws6 is a lt1 and i am pretty sure i have atleast 3.23's not 2.73's either way come next week i will have 3.73's and then i wont ever be left wondering.

The easiest way to tell (if RPO sticker is unavailable) if you have 3.23's is to look at the driveshaft, is it rusty? then it is steel and you have 2.73's, if it is shinny it is aluminum and you have 3.23. Sometimes the gear ratio is marked in grease crayon on the axle.

SteveC