I had a 2.73 rear in my car and replaced it with a 3.42 rear out of a M6 car. Now the 3.42 rear is making some whine noises. My 2 series carrier is out of the car & sitting on a bench. I have to redo one of them, and I'm leaning towards the 2 series because I can build it on the side while still driving the car. Is there any advantage to building one or the other? I'm going to be following the rear build up in the new High Performance Pontiac with new axles, rear cover with the caps, etc. I know they are both "weak", but is one weaker then the other? I'm not putting big #'s to the ground and I have an A4 with a stall and no plans to go any faster then 12.xx's.
Mike
BTW, I'm sticking with the 3.42's, I really like them. 3.73's is too much for my type of driving.

 

Are you saying you got a complete rear out of an M6 car, or just the carrier and gears? Reason I'm confused is, you say you have the 2 series carrier sitting on the bench. There is no difference in strength between the two. Get the right 3.42s for the 2 series and go at it.

 

LOL Sorry about that! Yes, I have 2 COMPLETE rears, disc to disc. The 2.73 rear is out of the car, sitting on a bench. I'm planning on doing 2 new axles, complete bearing & seal kit and new ring & pinion,T/A cover and most likely I will weld the axle tubes for added strength. Like I said, I drive this car daily and have no plans of getting crazy with the car......maybe a 100-125 N2O shot at the most. I read somewhere the 2 series was actually a little thicker gears.....that's the main reason I'm asking. Thanks for the input!
Mike

 

My understanding is 3 series gears for a 2 series carrier just have more material behind the gear teeth to make up for the difference in the flange thickness between the two. I wouldn't go to the expense of new axles since the drive gears or pinion gears break first anyway. Axles don't usually snap just start twisting and then break. You can look at the ones you have for signs of twist. Aftermarket axles can be pricey. My opinion, better to get a 12 bolt than put a lot of money into a stock rear.

 

Well, in some circumstances I would agree with that 100%.......BUT, there is now way I will ever need the durability of a 12 bolt. My car just isn't going to be much of a power monster! LOL If you read the article in the Pontiac High Performance magazine, it says that you can build the rear for a safe 450 HP. I won't come close to that! LOL Plus I doubt I will ever pull better then a 1.7 60'. I'll check the old axles and see how they look and go from there. Thanks for the input!
Mike

 

I understand. Good luck with the rebuild.