GM Rear Questions
- Thread starter ElCamMan515
- Start date
- Status
I caught one mistake in that article so there may be others............I have an 8.2 and it has the 5/16" pin
"Another way to tell the difference between an 8.2 and an 8.5 rearend is to pull the cover and look at the bolt holding the spider gear crosspin. If it takes a 1/2-inch wrench to remove it, it’s an 8.2. If it takes a 5/16-inch wrench to remove it, it’s an 8.5. "
I would bet on it being out of a late 70's A body. A tape measure is your best friend. The width will tell the truth regarding what it came out of. I am betting it will be wider than the 7.5" that came out of your car... Still might be do able, but check out the angles, location on the control arm mounts before you get carried away rebuilding it, though...
On the subject of tape measures, the article linked above misses the most obvious way to tell an 8.5" ring gear. (As mentioned above, using the wrench size on the cross pin bolt is not reliable. My uncle an old drag racer showed me an old racer's trick used to quickly I.D any ring gear O.D. First, pull the cover, lay the tape measure across the cover mounting flange with an inch or two hanging past the flange. Pick a number to begin your measurements and eyeball (or us a flat edge if you're cross eyed) where the edge of the ring gear starts. Then measure the width of the ring gear. (If you start at 2" and end up at 10.5", you have an 8.5" rear.) Some of you younger viewers will need to get your phone out and pull up the calculator for the last part).
Obviously I am being facetious (I had to look that up) with this, but last week I bought a $2.50 breakfast taco from a vendor who sets up in our building lobby and they were training a new girl. I gave her a $5 bill and she had to use her phone to figure change. Before I could catch myself, I said "Are you kidding me?" (They teach advanced trigonometry in school but kids graduate from high school and can't make change in their heads! I would venture to guess balancing a checkbook would equate to going to the moon to them...) Maybe it's because I worked in my parent's grocery store from around 6 or 7 y.o. til they sold it when I was 13 or 14 y.o....My wife and I are already working with our 7 y.o. daughter to make change. She already has it down pretty good. Now we are working on situations such as when a customer buys a $6 (item) with a $10 bill and a $1 bill. (They want a $5 back!) I have had to give up on this before and even had someone ask me if I was trying to trick them! LOL (RANT CONCLUDED)
On the subject of tape measures, the article linked above misses the most obvious way to tell an 8.5" ring gear. (As mentioned above, using the wrench size on the cross pin bolt is not reliable. My uncle an old drag racer showed me an old racer's trick used to quickly I.D any ring gear O.D. First, pull the cover, lay the tape measure across the cover mounting flange with an inch or two hanging past the flange. Pick a number to begin your measurements and eyeball (or us a flat edge if you're cross eyed) where the edge of the ring gear starts. Then measure the width of the ring gear. (If you start at 2" and end up at 10.5", you have an 8.5" rear.) Some of you younger viewers will need to get your phone out and pull up the calculator for the last part).
Obviously I am being facetious (I had to look that up) with this, but last week I bought a $2.50 breakfast taco from a vendor who sets up in our building lobby and they were training a new girl. I gave her a $5 bill and she had to use her phone to figure change. Before I could catch myself, I said "Are you kidding me?" (They teach advanced trigonometry in school but kids graduate from high school and can't make change in their heads! I would venture to guess balancing a checkbook would equate to going to the moon to them...) Maybe it's because I worked in my parent's grocery store from around 6 or 7 y.o. til they sold it when I was 13 or 14 y.o....My wife and I are already working with our 7 y.o. daughter to make change. She already has it down pretty good. Now we are working on situations such as when a customer buys a $6 (item) with a $10 bill and a $1 bill. (They want a $5 back!) I have had to give up on this before and even had someone ask me if I was trying to trick them! LOL (RANT CONCLUDED)
Last edited:
I do that with change all the time! I've seen cashiers almost melt in confusion. But then the register shows them what I did by doing the math for them!
After they got rid of the pennies in Canada the cashiers have lost all their common cents........😎
- Status
