Help identifying what gears I might have

[ddelauz]

I have an ‘86 K10 with 10 bolt 6 lug rear end. With the attached photos is there any way to tell what gears I have? The original sticker says I have 3.08 gears but not sure if it has been changed prior to be buying it.

 

[nvrenuf]

Not on a gm axle. IF THEY’RE ORIGINAL, you can decode the RPO codes (if you still have the sticker) to find the ratio.

Otherwise, the only option is pulling the cover and getting the numbers stamped in to the edge of the ring gear.

 

[ddelauz]

Thank you.

 

[ReefkoiC10]

Pretty easy, Mark the tire in one spot and the driveshaft in one spot with paint/chalk. Then turn one of the rear wheels 2 full revolutions and while doing that have someone count how many times the driveshaft rotated. So if the driveshaft turns 3 times and the tire 2 times thats a 3.00 ratio if its 3 and a quarter turns then its a 3:23 etc. its not 100% precise since you’d need accurate marks to get real real close but it Gets you damn close. Other than that pull the cover and get messy

 

[Ricko1966]

Pretty easy, Mark the tire in one spot and the driveshaft in one spot with paint/chalk. Then turn one of the rear wheels 2 full revolutions and while doing that have someone count how many times the driveshaft rotated. So if the driveshaft turns 3 times and the tire 2 times thats a 3.00 ratio if its 3 and a quarter turns then its a 3:23 etc. its not 100% precise since you’d need accurate marks to get real real close but it Gets you damn close. Other than that pull the cover and get messy

Something to add, if you don't have someone to watch you can tape a string,tied to a socket,etc. for tension to the drive shaft count how many string wraps +/- where the tape stops.

 

[Rickf]

A plus on pulling the cover is you can see if the gear oil has any water in it and can check for any sparkles in the fluid. You'll only be out some silicone sealant and 2 or 3 qts. of gear oil. If you've never smelt gear oil, if it smells bad, it's good.

 

[nvrenuf]

A plus on pulling the cover is you can see if the gear oil has any water in it and can check for any sparkles in the fluid. You'll only be out some silicone sealant and 2 or 3 qts. of gear oil. If you've never smelt gear oil, if it smells bad, it's good.

Don't forget the yummy smelling L/S additive. lol

 

[WFO]

Pretty easy, Mark the tire in one spot and the driveshaft in one spot with paint/chalk. Then turn one of the rear wheels 2 full revolutions and while doing that have someone count how many times the driveshaft rotated. So if the driveshaft turns 3 times and the tire 2 times thats a 3.00 ratio if its 3 and a quarter turns then its a 3:23 etc. its not 100% precise since you’d need accurate marks to get real real close but it Gets you damn close. Other than that pull the cover and get messy

Or if its a limited slip (positrac), only rotate the tire once.

 

[Ricko1966]

You know sometimes I just have too much time on my hands and think about stupid shet. It occurred to me you could put a piece of tape on the wheel arch with a line on it like a timing tab. put a matching line on the tire,push the truck to rotate the drive shaft exactly 1 turn place another mark on the tire. Measure distance between the marks.From that point it's a simple math problem to figure degrees of rotation. Just like timing tape on a balancer.

 

[squaredeal91]

You know sometimes I just have too much time on my hands and think about stupid shet. It occurred to me you could put a piece of tape on the wheel arch with a line on it like a timing tab. put a matching line on the tire,push the truck to rotate the drive shaft exactly 1 turn place another mark on the tire. From that point it's a simple math problem to figure degrees of rotation. Just like timing tape on a balancer.

That's about exactly how we did it at work, and It was pretty accurate!

 

[Turbo4whl]

Don't forget the yummy smelling L/S additive. lol

If you've never smelt gear oil, if it smells bad, it's good.

Mmmm, yummy

When you splash some on your clothes, you get to smell it all day, 'till your done work'n.

 

[Rickf]

Mmmm, yummy

When you splash some on your clothes, you get to smell it all day, 'till your done work'n.

Then burn the clothes.

 

[squaredeal91]

I guess I'm weird because I actually love the way gear oil smells. And I also like that petroleum smell you find deep in the engine when taking it apart.

 

[idahovette]

@squaredeal91 I think it must be an "acquired taste".........smell.......lol

 

[ddelauz]

Thanks for the tips!