IMO they both get the job done, especially on stock cars like ours.

 

ok guys , one question, i ordered 342's to be put in my 2 series carrier, does anything affect my abs sensor, does the shop have to take it out and put it back in or something, or i shouldn't worry about that since im bying gears for a 2 series. does he even have to fool arround with this sensor thing at all. im just worried about everything being put back together properly. i hope the shop thats doing it knows exactly what he's doing. thanks

 

I thought our stock rears already had an Auburn posi from the factory?

 

It is, but it is not the same as the aftermarket(and SLP optional 99+) Auburn.

I had 3.42's in my 98, and loved em, but went with 3.73's in this car, and wouldn't go back.

 

no, the abs sensor goes untouched, however, it may be a good time to get an install kit to have most of the stuff in there replaced while its apart.....I'm getting the ratech "complete" installation kit from www.thunderracing.com for $90

 

alright guys, this is what I ordered.

1 85-308TK Ratech Complete Gear Install Kit, GM 7.5" 10 Bolt $89.99 x 1 $89.99
1 85-4111 Ratech Solid Pinion Spacer (Crush Collar) GM 7.5" 10 Bolt $17.99 x 1 $17.99
1 23-875373-X Strange Pro-Street Gears, 3.73 Gear Ratio, 2 series carrier, GM 7.5" 10 bolt rear end $225.00 x 1 $225.00
Discount: $ 10.00
Tax: $0.00
Shipping: $9.99
Total: $332.97


Hopefully it will be here in about a week, and I'll get some PCM programming from Ion at Madz28.com.

 

How do I know if I have a 2-series or 3-series carrier?

<---- mechanically challenged

 

Same pile of parts I just ordered from Thunder this weekend! lol Less the solid pinion spacer though.. I'm for free with pcmforless, so I'm sticking with Bryan. I've seen nothing but good things said about Ion though..

 

If you have an A4 and can shift your car into 1st gear (from the factory) then you have a 3-series carrier and can simply buy the gears.

If you have an A4 and can only shift your car down to 2nd, you have a 2-series carrier and have to buy either thicker gears or gears and a 3-series carrier.

If you have an M6 car, you have a 3-series carrier.

 

Awesome - Preciate it - 3.73s here I come

 

Oh, 3.42s @ 70MPH with A4 = 2200 RPM

3.73s @ 70 MPH with A4 = 2400 RPM

My mileage went from 20 MPG w/ 2.73s to 18.5 MPG w/ 3.42s.

I'm LOVING my 3.42s.

I bought motives and they came apart on me, went with Strange Pro-Streets from Thunder and they're awesome! A little noise, but they're a performance gear, you got to give a little in sound to gain in strength I guess.

 

I was really really looking for a used rear with 3.42's because #1 I thought it would be easier and cheaper to just swap rears and #2 I thought 3.73's were just a little too much gear for me since the Z gets occasional trips on the highway. No further than 45 min to hour long trips here and there though. Since I've read this post I'm beginning to wonder wether I'm selling myself short or not. If 3.73's aren't that much different in gas mileage loss and rpm increase I might have changed my mind. My question is, I have a 3000rpm vig. stall, will 3.73's be too much for that stall? Basically will I end up hurting my traction because I'll be launching so hard or will it still help my ET's?

Thanks

 

Should be fine on Slicks - DRs might have some trouble depending on track prep - your Fugged on SRs

 

all I want to say about www.thunderracing.com is WOW! I ordered my stuff at about 3:30, and it was all shipped out by 6!!!!!

 

When I placed my original order with Thunder, I was told this:

"If you're going to put an upgraded stall converter in the car, you're best bet is 3.42s. If you're sticking with the stock converter, go with 3.73s"

This is most likely due to the increased torque multiplication (STR) of most upgraded converters being compounded by the increased torque multiplication of the 3.73s. I guess with the car coming into it's power band so much faster with the converter stalling up, there is concern of increased stress on the gears?

I don't fully understand the reasoning behind it, but I"m sticking with my 3.42s and planning a 2800-3000 RPM stall in the future.