Author Topic: Dif gearing  (Read 2572 times)

Offline Farm boy

  • Newbie
  • Posts: 99
  • Newbie
Dif gearing
« on: June 11, 2012, 07:28:40 pm »
Ok I'm sorry i know there are a bunch of threads on this but I just cant quite get it :-[

So I'm parting out my k10 and i have a guy that's interested in the front dif but needs to know the gearing. So I have looked in the glove box but the camper info sticker ether doesn't have that info or it's on the missing part. So I jacked up one front tire and turd the drive shaft till the tire made 2 turns. The drive shaft turned 3 1/10 to 1/8.

So my question is do you guys know what gear ratio that would be? Can I figure it out from the vin, so I know for sure? Or is there another number I could check?
K10-350 w/Holley 4bl, 350th, 33-12.5-15s, blue)-parting out
K10-350 w/Holly 4bl, bad th350 swapping to sm465, 33-12.5-15s, CAMO!

Offline Irish_Alley

  • Tim
  • Senior Member
  • ****
  • Posts: 13333
  • Family is not an important thing. It's everything.
Re: Dif gearing
« Reply #1 on: June 11, 2012, 08:02:46 pm »
the only way i know is to take the cover off the diff and do some math with the numbers. there is a way with the way you did but i dont know it and dont want to guess when you could just find out for sure and the oil should be changed out anyway, this way you can inspect the ring and pinion also
If you can’t tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline DustyRusty

  • Junior Member
  • ***
  • Posts: 567
Re: Dif gearing
« Reply #2 on: June 11, 2012, 08:19:23 pm »
As Irish said, you can take off the diff. cover, etc.  Count teeth on both the pinion and ring gears.  Divide the number of pinion gear teeth into the number of ring gear teeth.  That will be the ratio.  Sometimes the ratio is stamped on the edge of the ring gear.
1975 K-10 SWB Fleetside - 350/SM465/NP205/D44F 12-boltR, 3.73 gears.  Original owner.
Customized by rust.

Offline Farm boy

  • Newbie
  • Posts: 99
  • Newbie
Re: Dif gearing
« Reply #3 on: June 11, 2012, 08:23:22 pm »
Yah I should probably check it out before selling it anyway. It's just that I currently still have the truck assembled and would rather not take it out thus disabling the truck till I know he wants it. So I guess I will need to take it off still on the truck and eat the cost of new fluid.
K10-350 w/Holley 4bl, 350th, 33-12.5-15s, blue)-parting out
K10-350 w/Holly 4bl, bad th350 swapping to sm465, 33-12.5-15s, CAMO!

Offline Irish_Alley

  • Tim
  • Senior Member
  • ****
  • Posts: 13333
  • Family is not an important thing. It's everything.
Re: Dif gearing
« Reply #4 on: June 12, 2012, 02:13:07 am »
i wouldn't fill it back up just let him know. he would probably want to change fluids anyway
If you can’t tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline Farm boy

  • Newbie
  • Posts: 99
  • Newbie
Re: Dif gearing
« Reply #5 on: June 12, 2012, 07:35:34 am »
I meant if he doesn't want it do to wrong gearing, I'd probably fill it back up. But now that i think about it; since it's the front diff and it doesn't turn if not engaged I mite just leave it till I've sold it.
K10-350 w/Holley 4bl, 350th, 33-12.5-15s, blue)-parting out
K10-350 w/Holly 4bl, bad th350 swapping to sm465, 33-12.5-15s, CAMO!