Is there any measurement to tell what rearend, and what carrier a certain set of gears fit? A friend of mine said he ordered me a set of 3.42's for my 7.5" and they are for a 2-series. I just want to check before I pull my rearend apart.

TIA

Also, what is the difference in size between the 2 and 3 series carrier? Can I have a machine shop make me a spacer to make them fit?

TIAA

 

Look at the gears that are there. If they're 2.73 or 3.08, then you definitely have a 2-series carrier. If they're 3.23 or higher, it would be 3-series if they're factory.

The difference in gear thickness is about .4".

You could have a spacer made; you could also just buy one, which would be alot cheaper and more sensible that having one made, or buying the special gears. http://www.drivetrainspecialists.com...=28&cat=GM+7.5 search for the word "spacer" on the page

 

I know the diff is a 2-series. Its a 2.73 POSI. Just wondering about the gears themself.

Thanks for the site though.

 

If the gears are 2-series, then the carrier has to be 2-series. At least, I know of no way to make a spacer with negative thickness.... that is, when you put it in, the parts get closer together than without it.

The reason there's such a thing as a 2-series carrier in the first place, is because the flange on the carrier for the ring is moved over away from the pinion, to accommodate the larger pinion that you have to have with a lower numerical ratio. Remember, that ratio you're looking at is not just the ratio of the number of teeth, it is also the ratio of the diameter of the ring to the pinion; and since the ring is always the same size in a given model of rear end, a lower ratio pinion is larger than a higher ratio pinion. So the ring has to move over farther from the center of the pinion.

 

..........Nevermind.