1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Ring and pinion swap

Discussion in 'Differential & Driveline' started by Savageftr, May 3, 2021.

  1. Savageftr

    Savageftr Junior Member

    Posts:
    29
    Likes Received:
    38
    Joined:
    Mar 5, 2021
    Location:
    Elie, Manitoba Canada
    First Name:
    Alex
    Truck Year:
    1986
    Truck Model:
    C15
    Engine Size:
    355
    I have an 86 c15 with 3. 08 gears and a th350.

    I'm pulling a camper with the truck and it seems a bit too steep for this.

    Any issues just buying a 3.73 ring and pinion set? I should just need a new crush washer and set the depth, lash and pinion bearing preload again right?


    I'm plan on just keeping it an open diff.
     
  2. Bextreme04

    Bextreme04 Full Access Member

    Posts:
    1,473
    Likes Received:
    1,529
    Joined:
    May 13, 2019
    Location:
    Oregon
    First Name:
    Eric
    Truck Year:
    1980
    Truck Model:
    K25
    Engine Size:
    350-4bbl
    For the same price as a ring and pinion set and an axle rebuild kit, you could just get a 14bff with open 4.10's or 3.73's... just an option :emotions33:

    I have a 2011 Suburban that has 3.08's and we also pull a camp trailer, its a dog. I bought a set of 4.10's for both front and rear with the axle rebuild kits for both as well. I went with 4.10's since we have a 6L80E that has a double overdrive and we pull a lot through mountains here in the Pacific North-west.
     
    Catbox and Curt like this.
  3. Savageftr

    Savageftr Junior Member

    Posts:
    29
    Likes Received:
    38
    Joined:
    Mar 5, 2021
    Location:
    Elie, Manitoba Canada
    First Name:
    Alex
    Truck Year:
    1986
    Truck Model:
    C15
    Engine Size:
    355

    My buddy actually has a 14 bolt full floater I can have for next to nothing but I want to keep my stock rally wheels. I thought a ring and pinion swap would be the cheapest. about $250 plus/minus.

    The semi floating 14 bolts are hard to find I've heard and not cheap either.
     
  4. C10MixMaster

    C10MixMaster Full Access Member

    Posts:
    604
    Likes Received:
    946
    Joined:
    Dec 6, 2016
    Location:
    Kingman AZ
    First Name:
    Ben
    Truck Year:
    1977
    Truck Model:
    C10 BIG10
    Engine Size:
    ZZ4 350
    get an install kit there not that expensive ~ $70. you will need the shims / seal / crush sleeve / lock nut at the minimum. and if your going that far do the bearings and ring bolts to , which are all in the install kit.

    GM 12-Bolt rear diff UPGRADE: Positraction and gear swap | Hagerty DIY - YouTube this will give you an idea of what needs to be done.
     
  5. Snoots

    Snoots Supporting Member Supporting Member

    Posts:
    5,612
    Likes Received:
    8,349
    Joined:
    Jan 23, 2013
    Location:
    Georgia
    First Name:
    Roger
    Truck Year:
    1973
    Truck Model:
    Jimmy Sierra
    Engine Size:
    350
    I like the gear swap (3.73) but I'd spring for a posi carrier.
     
    82sbshortbed and Catbox like this.
  6. Grit dog

    Grit dog Full Access Member

    Posts:
    1,571
    Likes Received:
    1,885
    Joined:
    May 18, 2020
    Location:
    Washington
    First Name:
    Todd
    Truck Year:
    1986
    Truck Model:
    K20
    Engine Size:
    454
    Why would one go through that brain damage of making a 8 lug axle work under a 5 lug truck and not look like a pos with mis matched wheels?
    Can't tell by the :emotions33: if you are serious or joking.
     
    SquareRoot and Curt like this.
  7. Grit dog

    Grit dog Full Access Member

    Posts:
    1,571
    Likes Received:
    1,885
    Joined:
    May 18, 2020
    Location:
    Washington
    First Name:
    Todd
    Truck Year:
    1986
    Truck Model:
    K20
    Engine Size:
    454
    Depends how fast you want to drive on the highway.
    If your truck actually has a Turbo 350 swapped in it, it will be screaming at highway speeds with deep gear and the little tires that are on it.
    Think about what you want out of the truck. If just for towing, 3.73s or even 4.10s will be great, but not if you drive it 70mph+ on the highway. That's 3000-3300 rpms (3.73 vs 4.10) at 70 mph in drive.
     
  8. Bextreme04

    Bextreme04 Full Access Member

    Posts:
    1,473
    Likes Received:
    1,529
    Joined:
    May 13, 2019
    Location:
    Oregon
    First Name:
    Eric
    Truck Year:
    1980
    Truck Model:
    K25
    Engine Size:
    350-4bbl
    Mostly joking... but it is still a valid option. For a 2wd, it's pretty easy to convert to the bigger 3/4 ton 8-lug front rotor and caliper also... but if he has nice wheels and tires that's obviously not a good one.
     
  9. Savageftr

    Savageftr Junior Member

    Posts:
    29
    Likes Received:
    38
    Joined:
    Mar 5, 2021
    Location:
    Elie, Manitoba Canada
    First Name:
    Alex
    Truck Year:
    1986
    Truck Model:
    C15
    Engine Size:
    355
    The TH350 is factory not swapped. Its the MX1 rop code for a TH350C with the converter lockup. I'm happy driving 55 or 60 on the highway.

    The only longer trips I will be taking will be pulling the camper. I want to be able to drive 55 ish on windy days and not smoke the trans. Right now when its really windy you can tell the trans is under some serious load, hoping lower gearing should help take some stress off the engine/trans.
     
  10. Savageftr

    Savageftr Junior Member

    Posts:
    29
    Likes Received:
    38
    Joined:
    Mar 5, 2021
    Location:
    Elie, Manitoba Canada
    First Name:
    Alex
    Truck Year:
    1986
    Truck Model:
    C15
    Engine Size:
    355
    It would be nice but I'm not racing it or driving in the mud so the only use for it would be the occasional burn out...

    I figure less traction = less breaking shit

    I have lots of other shit I could spend $700 on right now that I actually need
     
    Ricko1966 likes this.
  11. Savageftr

    Savageftr Junior Member

    Posts:
    29
    Likes Received:
    38
    Joined:
    Mar 5, 2021
    Location:
    Elie, Manitoba Canada
    First Name:
    Alex
    Truck Year:
    1986
    Truck Model:
    C15
    Engine Size:
    355
    It would be nice but I'm not racing it or driving in the mud so the only use for it would be the occasional burn out...

    I figure less traction = less breaking shit

    I have lots of other shit I could spend $700 on right now that I actually need
     
  12. WesN

    WesN Full Access Member

    Posts:
    122
    Likes Received:
    252
    Joined:
    Feb 15, 2018
    Location:
    Edmonton Alberta Canada
    First Name:
    Wes
    Truck Year:
    1981
    Truck Model:
    C1500
    Engine Size:
    350
    Be aware that there is two different ring and pinions (thick vs thin) that will depend on which carrier you have. Carriers are made for a certain range of gear ratios and it will determine which gears will work with you stock carrier.
     
  13. Ken Boellner

    Ken Boellner Junior Member

    Posts:
    2
    Likes Received:
    0
    Joined:
    Jun 30, 2020
    Location:
    Arizona
    First Name:
    Ken
    Truck Year:
    1980
    Truck Model:
    C10
    Engine Size:
    302
    Just changed the 3:08's in my to 3:73. You have to change the carrier also.
     
  14. MikeB

    MikeB Full Access Member

    Posts:
    1,577
    Likes Received:
    650
    Joined:
    Apr 4, 2014
    Location:
    Justin, TX
    First Name:
    Mike
    Truck Year:
    1969
    Truck Model:
    C10
    Engine Size:
    355
    Carrier "break" for 8.5" 10-bolt is 2.56/2.73. That means 3.73 gears would work with your carrier even if your truck had 2.73 gears. Simply google it.

    Also, I would opt for a crush sleeve eliminator kit (spacer+shims). That way you don't need to torque the pinion nut to 300 lb/ft or more to crush a sleeve, and then throw it away if you mess up. https://www.yukongear.com/productdetails.aspx?ProdID=8280
     
    Ricko1966 and Bextreme04 like this.
  15. SquareRoot

    SquareRoot Full Access Member

    Posts:
    1,418
    Likes Received:
    1,944
    Joined:
    Mar 18, 2017
    Location:
    Arizona
    First Name:
    Mike
    Truck Year:
    85
    Truck Model:
    K20
    Engine Size:
    350
    Someone's about to go down a rabbit hole. On the plus side, if your truck has the factory 305 you ain't gotta worry bout breaking anything.
     
    Curt likes this.

Share This Page