I'm looking to put 4.10's in my 86 TransAm which has a GM 10 bolt with 3.23's right now. I noticed on Jegs that it has a full set of gears for a 2 series rear and a 3 series rear. What is the difference, and how do you figure out which rear you have, and wether a given gear set is for a 2 or 3 series?? Thanks.

 

If it came with 3.23s, then your carrier is 3-series; and the normal 4.10s will bolt right onto it.

People rarely use the special 2-series 3.23 gears.

You can look at the gears and tell easily with 3.23s. The ring teeth will appear to be very deep, they will look like they are cut almost all the way to the bottom of the gear material. If it's a 2-series carrier with the special gears, then the ring will be very thick; it will look like they leave almost 3/4" of material at the bottom of the space between teeth.

 

Just out of curiosity, is there anything wrong with low ratio 2-series gears? I have a set of Richmond 4.10's in my 84 TA with a posi carrier from a 2.93 gearset? Are they any weaker? Are my Richmond gears at least stronger than the stock ones?

 

No, nothing really "wrong" with them IMHO, just that they lock you into using a 2-series carrier, forever; unless you want to buy gears again. They're more expensive to make, because the extra-thick metal tends to warp more during heat-treating, and so requires extra care (or creates a higher QC reject rate).

There's 2 kinds of Richmond gears. They make regular stock replacement ones, which are a good quality gear, and are just that.... stock replacement. They are hardened very hard like other stock replacement gears, for longevity. The other kind of Richmond gears, the one people usually mean when they say "Richmond gears", is purpose-built for drag racing. They are much softer metal, to avoid shattering like the very hard stock-type ones will, and have a tooth design with less sliding action. They are far more durable in a drag racing application, but the same things that make them so, also make them noisy and much less durable in a street application. It's a compromise.... give up one set of characteristics in order to improve another set.

 

This sounds dumb, but how can I tell if I have the stock replacement or the softer ones for drag racing? Should I be worried about breaking them? They are in my 84 TA, L-69 5-speed.

 

Look at the receipt.

There might be a part # on the gears themselves that you could look up, I don't know that for sure.