what kind of gears in my housing?

[westpoint]

I have a 82 Silverado. When the rear is off the ground and I spin one tire the other tire travels opposite. I would like to get posi but I need the truck for the street. What do I have now? Also what do I need for the street but no one wheel wonder? Thanks.:metal

[J Knight]

"Most likely" in an 82 you have a 10 bolt with 2.75 or 3.08 open diff.

You can remove the rear cover and count the teeth on the ring and pinion then divide one into the other to get your gear ratio. You might find the tooth count stamped on the ring gear.

[riz]

You can also count how many revolutions your driveshaft turns for one rotation of your tire. Simple math.

RIZ

[xrcr]

You can go to gm heritage.com and see what that truck came with and then do the spin deal

[westpoint]

Originally Posted by J Knight

"Most likely" in an 82 you have a 10 bolt with 2.75 or 3.08 open diff.

You can remove the rear cover and count the teeth on the ring and pinion then divide one into the other to get your gear ratio. You might find the tooth count stamped on the ring gear.

i count 12 bolts on the housing cover. whats that tell me?

[J Knight]

Originally Posted by westpoint

i count 12 bolts on the housing cover. whats that tell me?

From what I have read, they stopped putting 12 bolt rear ends in trucks in '81 so it might have been swapped from a 10 to a 12 at some point. You need to count the teeth or spin the wheels and count the revolutions of the yoke to find out what ratio you have.

[westpoint]

Originally Posted by J Knight

From what I have read, they stopped putting 12 bolt rear ends in trucks in '81 so it might have been swapped from a 10 to a 12 at some point. You need to count the teeth or spin the wheels and count the revolutions of the yoke to find out what ratio you have.

How do you count the revolutions of the yoke?

[Tx Firefighter]

Jack one rear wheel off the ground. Put transmission in neutral. Turn the wheel two turns exactly. Count how many times the yoke turns as you turn the wheel twice.

[westpoint]

Looks like I have a 2.63 gear ratio. 43 and 16. What does that tell me? Im not sure how gears work. Confusion to me. If I upgrade to a Eaton posi unit which one do I buy?
my dad recommends a 4.11. What do you think and when can I get one decent price? Thanks.

[Keith Seymore]

4.11 is pretty steep. It will deliver a big jump off the line but not very good fuel economy. 2.63 (43/16=2.68) will deliver better fuel economy (assuming it is not bogging/lugging the engine) but will be a dog off the line.

For all around street use I like a 3.73-ish when I have an overdrive trans, or a 3.42-ish when the highest gear in the trans is a straight 1:1.

K

[J Knight]

Originally Posted by westpoint

Looks like I have a 2.63 gear ratio. 43 and 16. What does that tell me? Im not sure how gears work. Confusion to me. If I upgrade to a Eaton posi unit which one do I buy?
my dad recommends a 4.11. What do you think and when can I get one decent price? Thanks.

What do you plan on using the truck for? What motor, tranny, and tire diameter do you have or plan on having? All these things and more play into picking the right gear ratio.

[westpoint]

Originally Posted by J Knight

What do you plan on using the truck for? What motor, tranny, and tire diameter do you have or plan on having? All these things and more play into picking the right gear ratio.

Im looking to keep the truck tire size and stance close to stock. Right now it has a 305 in it. I would like to put a bigger motor in it eventually or just increase the horse power in the 305. I will be using this truck to drive everyday. 10 miles one way to work plus errands. Hope that helps.


I have another dilemma.... I removed the drive shaft. I also remove the front of the differential where the seal cap, bearing and race are. How do I remove the race? Do I need to remove all the gears in the housing to replace the race for the new bearing? Thanks for all the help.

[J Knight]

Originally Posted by westpoint

Im looking to keep the truck tire size and stance close to stock. Right now it has a 305 in it. I would like to put a bigger motor in it eventually or just increase the horse power in the 305. I will be using this truck to drive everyday. 10 miles one way to work plus errands. Hope that helps.

Originally Posted by Keith Seymore

4.11 is pretty steep. It will deliver a big jump off the line but not very good fuel economy. 2.63 (43/16=2.68) will deliver better fuel economy (assuming it is not bogging/lugging the engine) but will be a dog off the line.

For all around street use I like a 3.73-ish when I have an overdrive trans, or a 3.42-ish when the highest gear in the trans is a straight 1:1.

K

I would go with Keith's recommendation.^^^