rear gears 3.23 vs ?

**Blue Bird** · 07-05-2011, 07:48 AM

With 259,000 miles it is time to replace my rear gears. Should I stick with the stock 3.23 or go to a 3.73? I am not planning to take long road trips, but I don't run it at the track very often either (being that it is a vert). Let me know what you think.

**pajeff02** · 07-06-2011, 09:03 AM

I started with a 3.23 stock rear and then went with a Moser 12 bolt and 3.73's in our car. Despite this being the recommendation for A4 cars, I think I could have easily went with 3.90's (or whatever the next ratio is) and been just as happy. The 3.73's work great and are not a problem cruising on the freeway. Just a matter of personal choice for you.

**Ortiz11b** · 07-06-2011, 09:19 AM

I have 3.23 in my car also.. and like the way they feel.. but i will be swapping out to 3.73 down the road.. just has a better feel on take off.. (just my personal opinion.. and should still be under 2000 rpm at 70.. on the highway.. guess just depends on how you like to drive you car.. good luck...

**INMY01TA** · 07-06-2011, 05:11 PM

3:73.

**Blue Bird** · 07-12-2011, 07:50 AM

Thanks for the responses guys, I appreciate the feedback.

**oldmanZ28** · 07-13-2011, 03:48 PM

torque increase to the pavement
3.23 to 3.73 = 15%
3.23 to 3.90 = 21%
3.23 to 4.10 = 27%

rpm at 65mph
3.23-1925
3.73-2235
3.90-2335
4.10-2450

I'm A4 w/4.56s'

**Ant71130** · 07-14-2011, 04:35 AM

I got 4.10s and got no problem being at 2k rpm @ 70mph. M6 though :P. I'd definitely change the gears up, is the single biggest feeling mod you can do I hoenstly think. Wakes these cars up massively.

And... A4 with 4.56s? Damn dude lol.

**oldmanZ28** · 07-14-2011, 09:27 AM

Yeah,A4 w/4.56s',since 2007. Includes 4 trips from Cleveland Ohio to Florida,mpg at freeway legal speeds was 21.5. 1st & 2nd gear are awesome. 4.56s' are too steep for the 1/4 as I had to be in 4th(OD) for the traps.

**Blue Bird** · 07-15-2011, 07:38 AM

A guy that used to work at a Pontiac dealership told me that some people that geared up had driveshaft balance issues. Have any of you experienced anything like this?

**silverWS6** · 07-15-2011, 09:17 AM

Originally Posted by Blue Bird

A guy that used to work at a Pontiac dealership told me that some people that geared up had driveshaft balance issues. Have any of you experienced anything like this?

I'm having that problem right now

I have 4.10's and M6 and above 90ish car shakes but only in deceleration...

**Ant71130** · 07-15-2011, 10:26 AM

Originally Posted by silverWS.6

I'm having that problem right now

I have 4.10's and M6 and above 90ish car shakes but only in deceleration...

Luckily I don't have that issue

but they do whine, badly from like 50-70

**oldmanZ28** · 07-15-2011, 10:59 AM

no problem with the 4.56s'.
I believe there was a 'tech service bulletin' for the steel driveshaft that came with 2.73s'. If a customer complained of vibrations,replace the 'steelie' with the aluminum version.