hey guys, i currently have the stock 2.73 gears (with the 115 mph speedo) anyway, i am looking to get 3.73 gears, or possibly 4.10's my question, is how much of a difference will i notice, which should i go for? what brand, and what website should i buy them from? i was told i need some type of spacer if i am going from 2.73's? also, i plan on having them put in by somebody professional. should i go to a pontiac dealership? or what? also, will they be able to recal my speedo. i know these are alot of questions, but i need to know before i buy.
thanks
i also have an auto

 

I'm currently making the same change. I'm going from a 2.73 to a 3.73. I've been looking at a lot of posts and 4.10 seems to be too much with the A4, unless you never go on the e-way. The 2.73 is in a smaller carrier so they will have to use a spacer when they put in the new gear. I wouldn't go to the dealership though, they will charge an arm and a leg. Most places around me charge about 250 for the install and that's with the kit. As far as brands, I'm going with a motive. Some of my buddies have those and they have no noise.

 

I was going to do 2.73 to 3.73 as well. However my tranny broke .

 

Just a thought. If you have the 115 mph speedo does that mean the car is speed limited from the factory to approx. 115? If so, and you don't do a reprogram or speedo gear or anything, I'd say your top speed will be lowered quite a lot w/3.73's. Your driveshaft will be spinning faster to get the car to the same speed, and it will think (show on the speedo.) that it's going faster than it really is, which means your limiter would kick in sooner. Right? Well, in any case, a recalibration of some sort should fix this problem, but I'm really not sure of what kind you will want. I think if I were you, and of course, I'm a speedfreak at heart, I would try to have the speed limiter moved up or deleted.


Best of luck, and I hope this helps a little.
---J.Bird