reeperz28

iTrader: (1)

Ok as the title says what I have, I bought 3.42 rear gears from a m6 that had 30,000 miles on it and bought them for 20 bucks and a sixer ha. I went ahead and bought the ratech 10 bolt complete install kit and I'm new at this and have no idea what I need. New to rear ends I been reading about 3 series carriers and 2 series carriers and ect ect. What else do I need ??

2.73's

bigj2717

iTrader: (15)

Well your rear end is a 2 series and the gears you got are for a 3 series carrier. You can either buy a spacer for the ring gear to get it to work, buy a 3 series carrier and put it in your housing, or sell the gears and get the right 2 series gears. You have to do one of those because those gears will not just drop into your rear end the way it is

01ssreda4

iTrader: (96)

1. Buy 2 series 3.42s from Motive.
2. Get a matching 3 series posi to work with the 3.42s you already have.
3. Get a ring gear spacer.

I like option 3 the least.

reeperz28

iTrader: (1)

Thx probably go with 2 series carrier gears most likely . Is there reccomendations from going 2 series carrier to a three? Is it better or worse what's the scoop

FirstYrLS1Z

iTrader: (4)

A 2series carrier with a 3.42 'thick' gear set performs(power/torque/acceleration) the same as a 3series carrier with an OEM 3.42 'standard/regular thickness' gearset.

guppymech

iTrader: (7)

It seems like you were going with the 3.42s cause the price was right. Since you now have to buy gears to match your carrier, have you thought about getting 3.73s?

FirstYrLS1Z

iTrader: (4)

3.23s'/3.42s' are better in the performance realm than 2.73s',^^^agree,3.73s' are even better.

WhiteKnight '01

Don't mean to hijack this thread. but is there much of an MPG difference between 2.73's and 3.42's and son on and so forth? I got the 2.73's, but if I'm going to lose MPG's I don't want to move up to 3.42's.

01ssreda4

iTrader: (96)

Gonna be very close to the same....

WhiteKnight '01

Fuel economy will be mostly the same? How much would I lose? 1MPG in city and 1MPG on highway?

FirstYrLS1Z

iTrader: (4)

'Guesstimates' of real world mpg with a 98-02 A4,torque convertor locked,cruising in cruise control at freeway legal speeds.

2.73 - 25.9
3.08 - 24.7
3.23 - 24.5 *
3.42 - 24.0
3.73 - 23.0
4.10 - 22.2
4.56 - 21.5 *

* - what I got on many trips from Ohio to Florida

WhiteKnight '01

Very helpful info. You say the torque convertor was locked? That means you didn't have your aftermarket stall in it, right?

And my car averages 25-26MPG on highway trips, and I have the 2.73's, so that seems fairly accurate.

FirstYrLS1Z

iTrader: (4)

LS1 torque convertors 'lock-up'(1:1 in/out of convertor) at a speed for cruising.
My OEM or my TCI 2800 or my current Yank SS3600 all lock up at about 40 mph.

reeperz28

iTrader: (1)

3.73's for sure since I have to buy new gears anyway. When I was completely stock other than descreened maf k&n filter in stock box and gutted cats in stock exhaust I was averaging 29mpg