Question on a rear end swap

[98ls1blackbird]

I have a 98 LS1 trans Am A4 with 2.73 rear end. I just bought a complete 3.42 rear end from a 95 LT1 Z-28, this is complete from caliper to caliper. Is this a direct swap? Thanks.

[RamAirZ]

The only difference you might have is the ABS and traction control setup if your 98 is equiped with it. BUT you can swap that stuff onto the new rear so go right ahead :) Oh and don't remember but think the LS1 had a larger rear rotor, if so you can swap that stuff too

[98ls1blackbird]

I thought that might be the case, I do not have TC on the 98, and as for the brakes, I thought seeing as though 80% of the stopping is done with the fronts, I would just run the slightly smaller rear rotors. I dont do much high speed driving, mainly street and DOT drag racing. I only turn about 102 in the quarter and with next years improvements I probably will go 105-106, so I dont think the smaller brakes will be a problem. Thanks.

[Chris 96 WS6]

Brakes are different...though if it complete it still might swap out. ABS may be different too.

[98ls1blackbird]

Yes, the rear end is complete with brakes, calipers etc. I'm hoping the ABS connection is the same.

[CKJ]

Yes, the rear end is complete with brakes, calipers etc. I'm hoping the ABS connection is the same.

3.42's from what i only heard off came factory in 6 speed cars, which are the 4 channel ABS. 2.73's come in A4's which are a 3 channel rear. Your in a sticky situation. You could just swap the guts due to the fact that the 2.73's are a 2 series carrier and the 3.42's are a 3 series carrier. I think that would work. Might want to get some more info on that.

[98ls1blackbird]

Yes the 3.42 rear end is out of a 6-speed manual car. Guess I will have to swap the guts. I was hoping it would have been easier. Oh well, at least I got it for a good price. Thanks guys.

[CKJ]

Just get some 3.42 gears for a 2 series carrier. They'll be stronger than a 3 series carrier. Might be a little noisy unless you can find some factory gears.

[98ls1blackbird]

Just get some 3.42 gears for a 2 series carrier. They'll be stronger than a 3 series carrier. Might be a little noisy unless you can find some factory gears.

Why would gears for a 2 series carrier be stronger? My drive line guy cautioned against using three series gears in a 2 series carrier for the same reason, the extra width of the ring gears would make them weaker. That is why I bought a 3 series rearend. Now I'm really confused.

[CKJ]

I havn't seen many people break a 2 series carrier rear w/ 2.73's. Wider gear = stronger. Wider anything equals stronger. Its kinda like when you build something out of metal, what would you rather have for strenght. a 1/4" piece or a 1/2" piece. I'd say wider is better ;)

[98ls1blackbird]

Hmmmmmmmmm, gotta think about this one for awhile.

[koolaid_kid]

The 3.42 gears from Strange and Motive that are made for the 2 series carrier are thicker. The other brands use a spacer, which is not recommended.