Deciding on 12 bolt limited slip

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Obwonkonobe

Full Access Member
Joined
Feb 21, 2017
Posts
531
Reaction score
116
Location
AZ
First Name
Ethan
Truck Year
78
Truck Model
C10 custom deluxe
Engine Size
350
Found a good deal on what should be a working limited slip 12 bolt carrier. But before I go and buy it I want to be sure I have my facts straight, and the rest of the internet is pretty scarse for info.

So currently I have a 12 bolt rear in my c10 with 3.08 open gears. I found a "12 bolt limited slip carrier" on craigslist, says it had 3.73s on it and came out of a 75 truck rearend like mine. Should my 3.08 gear set just bolt right to it, and then I bolt the new carrier in place? From my understanding if I keep the gearset the same it should all work out so I don't have to shim it. Should the axles just slide out, then I unbolt the side bearings, then remove the carrier, transfer the ring gear to the limited slip, and bolt it back up? If anyone could point me to an article or something I missed I'd appreciate it, thanks
 

Obwonkonobe

Full Access Member
Joined
Feb 21, 2017
Posts
531
Reaction score
116
Location
AZ
First Name
Ethan
Truck Year
78
Truck Model
C10 custom deluxe
Engine Size
350
There's a pic

You must be registered for see images attach
 

Snoots

Full Access Member
Joined
Jan 23, 2013
Posts
8,197
Reaction score
16,064
Location
Georgia
First Name
Roger
Truck Year
1973
Truck Model
Jimmy Sierra
Engine Size
350
Should my 3.08 gear set just bolt right to it

Yes

and then I bolt the new carrier in place

Not without checking shims.

if I keep the gearset the same it should all work out so I don't have to shim it

BS. Your carrier is not the same. Minor differences. That's why shims.

Always use gear dye to check the 'footprint' of the gears before calling it a day. Shim until its right.

You'll likely need a new crush sleeve on the pinion too.
 

Jrgunn5150

Questionable methods
Joined
Jan 11, 2016
Posts
2,739
Reaction score
1,412
Location
Ionia Mi
First Name
J.R.
Truck Year
1979
Truck Model
C10
Engine Size
6.slow
Yes



Not without checking shims.



BS. Your carrier is not the same. Minor differences. That's why shims.

Always use gear dye to check the 'footprint' of the gears before calling it a day. Shim until its right.

You'll likely need a new crush sleeve on the pinion too.


Precisely this, there is almost 0 chance you put all the same shims back in and it just works. You'll also need a new pinion seal and crush sleeve.

This is why the Lock Rite and SPartan lockers are so popular, they just pop in, no upsetting the gears.
 

4WDKC

Full Access Member
Joined
Jan 27, 2016
Posts
2,366
Reaction score
1,090
Location
Southern Florida
First Name
Kacy
Truck Year
1987
Truck Model
V10
Engine Size
350
isnt the 12 bolt weaker than the 10 bolt?
 

Obwonkonobe

Full Access Member
Joined
Feb 21, 2017
Posts
531
Reaction score
116
Location
AZ
First Name
Ethan
Truck Year
78
Truck Model
C10 custom deluxe
Engine Size
350
Nah, it'll be fine. Man up. Bolt that **** in and run it. Don't listen to these guys. What would they do on Roadkill?

You have no idea how tempted I am to do that, but its my daily and itll see freeway use lots over the summer for my job
 

Obwonkonobe

Full Access Member
Joined
Feb 21, 2017
Posts
531
Reaction score
116
Location
AZ
First Name
Ethan
Truck Year
78
Truck Model
C10 custom deluxe
Engine Size
350
Yes



Not without checking shims.



BS. Your carrier is not the same. Minor differences. That's why shims.

Always use gear dye to check the 'footprint' of the gears before calling it a day. Shim until its right.

You'll likely need a new crush sleeve on the pinion too.

Good info thank you, il probably just keep the opens for now
 

crazy4offroad

Equal Opportunity Destroyer
Joined
Jul 30, 2010
Posts
8,468
Reaction score
1,070
Location
West BY-GOD Virginia
First Name
Curt
Truck Year
1979
Truck Model
K-10
Engine Size
350/SM465/NP205
Your old shims will get you close, then smear some white lithium grease on the ring gear teeth to check the pattern. Google "ring and pinion mesh pattern" and hit images and it will give you examples of good and bad patterns. Setting backlash is where you will likely have trouble if you don't have a dial indicator, and pinion bearing preload if you don't have an in/lb torque wrench. You can re-use the crush sleeve, just put it on the horn of an anvil or vise and hammer the "crush" section to lengthen it.
 

Snoots

Full Access Member
Joined
Jan 23, 2013
Posts
8,197
Reaction score
16,064
Location
Georgia
First Name
Roger
Truck Year
1973
Truck Model
Jimmy Sierra
Engine Size
350
Nah, it'll be fine. Man up. Bolt that **** in and run it. Don't listen to these guys. What would they do on Roadkill?

We'd make a more interesting show. And, we're much better looking.

If you can get your hands on a GOOD 12 bolt punkin for a decent price by all means do so.

You'll be glad you did someday.
 
Last edited:

ali_c20

Full Access Member
Joined
Sep 20, 2016
Posts
1,030
Reaction score
1,397
Location
Austria
First Name
Alexander
Truck Year
1974, 1979
Truck Model
C20, K5
Engine Size
350, 350
I changed from open diff to limited slip and reused my gears. Check that you have a good mesh pattern on the gears and the right backlash. It's not rocket sience, your done with it in half a day.
 

malibuman402

Member
Joined
Aug 2, 2015
Posts
44
Reaction score
40
Location
nc
First Name
Larry
Truck Year
1984
Truck Model
C10 Silverado
Engine Size
BB 402+.060 = 413.8CI
you dont need to remove the pinion to put a different carrier in it. check gear mesh and backlash.
 

78C10BigTen

Full Access Member
Joined
Apr 12, 2017
Posts
15,605
Reaction score
24,066
Location
pennsylvannia
First Name
Ted
Truck Year
1978
Truck Model
C10 BIG TEN
Engine Size
350
Found a good deal on what should be a working limited slip 12 bolt carrier. But before I go and buy it I want to be sure I have my facts straight, and the rest of the internet is pretty scarse for info.

So currently I have a 12 bolt rear in my c10 with 3.08 open gears. I found a "12 bolt limited slip carrier" on craigslist, says it had 3.73s on it and came out of a 75 truck rearend like mine. Should my 3.08 gear set just bolt right to it, and then I bolt the new carrier in place? From my understanding if I keep the gearset the same it should all work out so I don't have to shim it. Should the axles just slide out, then I unbolt the side bearings, then remove the carrier, transfer the ring gear to the limited slip, and bolt it back up? If anyone could point me to an article or something I missed I'd appreciate it, thanks
I am too in the same boat as my 12 bolt LS (3.08) is in many pieces and is essentially an open right now. But im looking to go quick and easy being mines 2wd and swap in a 10 bolt 3.73 LS whole rear end and be done. (Swapping out axles from 6 lug to 5 of course)
 

Latest posts

Forum statistics

Threads
42,220
Posts
911,628
Members
33,727
Latest member
Ls85c10man
Top