3.42 tp 4.10 swap!!!

**a338566** · 05-07-2008, 07:29 AM

MY 2001 TA has the t-56 6 speed and i ordered a set of 4.10 gears and the intall kit last night, however my dad thinks that puting in 4.10 gears is going to kill the way my car drives. Is this correct? it seems like alot of people put in 4.10 gears that have a t-56. This car is a weekend hot rod not a daily driver and may one day see a track but not often. This step is also preliminary to my cam install i will be doing soon

Thanks for the help

**GatorSS** · 05-07-2008, 07:56 AM

If it were your daily driver or your weekend driving frequently involved long highway trips, then your dad's thoughts would have some merit concerning fuel mileage. As a weekend hot rod, it will greatly enhance the way it drives... and your pleasure from driving it.

**jimmybling31** · 05-07-2008, 08:01 AM

Originally Posted by a338566

MY 2001 TA has the t-56 6 speed and i ordered a set of 4.10 gears and the intall kit last night, however my dad thinks that puting in 4.10 gears is going to kill the way my car drives. Is this correct? it seems like alot of people put in 4.10 gears that have a t-56. This car is a weekend hot rod not a daily driver and may one day see a track but not often. This step is also preliminary to my cam install i will be doing soon

Thanks for the help

4.10's feel great. they offer so much better acceleration.

**a338566** · 05-07-2008, 08:02 AM

what am i looking at for RPM's at 70MPH w. 4.10, i am currently about 1750 ish w/ 3.42

**jimmybling31** · 05-07-2008, 08:07 AM

Originally Posted by a338566

what am i looking at for RPM's at 70MPH w. 4.10, i am currently about 1750 ish w/ 3.42

correct me someone who knows better, but I think you will be around 2300-2400. I think I will be at 3000 with my new gears I'm putting in my a4

**GatorSS** · 05-07-2008, 08:14 AM

Approx. 2200

**Bottesini** · 05-07-2008, 08:21 AM

http://www.f-body.org/gears/

One of the great things about a six speed is that changing gears does not affect your highway gas mileage much. In the lower gears you will notice a big difference, and depending on how you drive you might find the car gets better mileage (rare, but for some people it does happen).

**Danger731** · 05-07-2008, 08:34 AM

Originally Posted by jimmybling31

4.10's feel great. they offer so much better acceleration.

Yes but, having to shift more often equals the times. Fact observed.

**rc74racer** · 05-07-2008, 12:27 PM

I've found nothing negative about this swap. I get only 1mpg less around town and almost the same on the highway. I'm not shifting anymore because I find myself skipping gears more often. Traction is even worse now but it was a problem before too. I'm right around 2k at 70mph and my speedo has been corrected.

**rc74racer** · 05-07-2008, 12:29 PM

Originally Posted by Danger731

Yes but, having to shift more often equals the times. Fact observed.

That's complete nonsense.

**Midnight02** · 05-07-2008, 12:43 PM

From a driveability standpoint, 4.10s will really wake your M6 up. Your city mileage shouldn't be negatively impacted (you will simply use 5th and 6th gear more often) and your highway mileage may see a nominal decrease. I was concerned about the loss of fuel efficiency when I was contemplating my gear swap, however that turned out to be a complete non-issue.

**00 formula** · 05-07-2008, 12:54 PM

not to thread jack but how much of a gas mileage impact would a swap to 4:10s have on an A4?

**Danger731** · 05-07-2008, 02:05 PM

Originally Posted by rc74racer

That's complete nonsense.

ok

**jimmybling31** · 05-07-2008, 03:14 PM

Originally Posted by 00 formula

not to thread jack but how much of a gas mileage impact would a swap to 4:10s have on an A4?

I got about 13-15 when I had them on there for all of 2 days, before I took it back to the shop and had them put a 2.73 in there with another used differential. it was the same cost at the shop I went to and it had a 21 day warranty and all that I was happy and it was absolutely sick, but it was horrible on gas.

**00 formula** · 05-08-2008, 05:25 AM

Originally Posted by jimmybling31

I got about 13-15 when I had them on there for all of 2 days, before I took it back to the shop and had them put a 2.73 in there with another used differential. it was the same cost at the shop I went to and it had a 21 day warranty and all that I was happy and it was absolutely sick, but it was horrible on gas.

Wow, what do you get normally for gas mileage?

**550hpbird** · 05-08-2008, 05:42 PM

I'd stick with the 3.42 gears if you are going to do any mods at all. I had 4.10's but went back to the factory 3.42 gears as I added the mods and couldn't be happier.

**badazta** · 05-08-2008, 05:53 PM

I had 4.10s installed just lastnite, speedo isn't corrected yet but its around 1750 at 65 with a 6 speed. Did I notice any difference? I'm not sure. Mines a daily driver with 275/40/18s on the back. I am modded too.

**00 formula** · 05-09-2008, 05:31 AM

Originally Posted by 550hpbird

I'd stick with the 3.42 gears if you are going to do any mods at all. I had 4.10's but went back to the factory 3.42 gears as I added the mods and couldn't be happier.

I'm not looking for any major mods since mine is a daily driver, just the basic bolt ons.

Being a daily driver I don't want to loos a lot of gas mileage though either. So I was just curious how big an impact it makes on an A4

**INMY01TA** · 05-11-2008, 08:14 PM

Originally Posted by Danger731

ok

He's right dude. Wtf are you talking about?

**Fury_786** · 05-13-2008, 04:39 AM

did you order the cross pin for your rear end?

someoen correct me, but on that series carrier, it takes a special cross pin when swapping to 4.10's and lower?