ok so i wouldnt really be changing out my rear, just an open rear 3.23 but i randomly came across a camaro 10 bolt posi 3.42 and couldnt stop myself, i didnt want to grab the whole axle so im just pulling all the gears and probably the axles(left and right or whatever) so will these go straight into my rear, its a 10 bolt as well and how will i correct the speedo, i know theres a speedo gear in the tranny or something.... also does the big *** bolt for the part that connects between the driveline and gear have to be measured, like torque wise or do i just pull it off and crank it down when i get it in mine? Thanks!!!

 

is there anything wrong with the axle housing of that camaro?
I would just swap the entire rear end versus swapping the insides, especially if you never messed with gear installs before.

 

well i took the pumpkin off already so...but thats what im thinkin, i would just rather kept mine in? oh well

 

Ok so im just gonna pull the whole rear, now how do i adjust the speedo after i drop the rear in? My uncle probably knows but i would like a litle info on it first, from dearching my understanging is that the speedo gear is in the tranny and i have to change that? How does that all work? Thanks and I will have the rear tomorrow night!!!

 

For the 3.42 ratio you need to change both of the speedo gears. The one on the trans output shaft and the one on the end of the speedo cable. The gears you'll need for the 3.42 ratio are the gray 15 tooth gear for the trans output shaft and the yellow 42 tooth gear for the end of the cable. These gears should calibrate your speedo about right where it needs to be. You can still buy them at just about any GM dealership. All ratios 3.23 and numerically lower use a red 17 tooth gear on the trans output shaft, all ratios 3.42 and numerically higher use the gray 15 tooth gear.

 

i was reading on a site that you can go with 15 16 or 17 but to stay with 15 17 so if i know whats in my tranny cant wen calculate the other other with that one

 

You might be able to do that if you can figure out which gear will work with the drive gear you already have I guess. I just posted the gear combo that I know is correct for 3.42. If you had anything less than 3.42 originally, I guarantee you've got the red 17 tooth drive gear in your trans right now. You can do the math and see if there's a gear available to match the 17.

 

3.23 open going to a 3.42 posi

 

where do i find the code or whatever it is that is printed on axle to get specifics? I know its out of a camaro, its a 10 bolt posi and is somewhere in the 3.42 vicinity, maybe 3.45, ill have to count gears to be sure. And how do you figure out whats already in the tranny, as in the speedo gear? does mine have the 15 or 17?

 

Trust me, if you had 3.23's originally, you have the 17 tooth speedo gear in the trans. The 15 tooth gear is only for 3.42 and numerically higher. As far as what gears are in the new rearend, take off the cover and look. That's the only way to know for sure what they are. I don't even bother looking for the factory code that's stamped on the axle tube. It's usually a PITA to find anyways. Besides that, you never know if the gears have been changed by a previous owner either.

 

Here's how to determinne what ratio the rear is (jerk the diff cover and look): numbers are stamped on the ring and pinion:

41 : 15 = 2.73
40 : 13 = 3.08
42 : 13 = 3.23
41 : 12 = 3.42
41 : 11 = 3.73

JamesC

 

ok also theres something you forgot, camaro has a 3.45 rear too, ill just count the gears and divided, i was wondering about numbers so i can see the year it was made. what is the other gear i replace not in the tranny for the speedometer fix?

 

I don't buy it. When I did a 3.23 to 3.42 gear swap, I did not have to change the drive gear in the tranny. And the dealer cross-checked it for me. And my speedo is accurate - checked it against a GPS unit.

It has been a while since I did the swap, but I could check it the stuff in my garage tonight...

And I know what gear WAS in the car and what gear IS in it now - I am the original owner.

 

That is a 9 bolt ratio, along with 2.77, 3.27, and I think 3.70.
9 and 10 bolt ring and pinions are not interchangeable.

 

ah gotcha, itd be so easy to see the gears but no ones home right now to help me pull it out of the back of my car, and that thing is Frikin heavy

 

Edit.

JamesC

 

thats odd that you wouldnt have to change the gears? Hmmmm