Upgrading an open diff to a lunchbox locker?

[78 GMC Jimmy]

So I'm revisiting the idea of changing my open rear diff to a locker or some sort.

I need to replace all the seals in the axle anyway, so I might as well do it all.

Whats the absolute cheapest way to get a locking rear diff? Amazon has them for $260, but I'm assuming its the wrong model for my rig.

78 K5, 8 lug, 14 bolt, FF. Anyone got a link to a cheap locker that would work? eBay? Amazon?

Am I better off just swapping the whole axle for a used one?

 

[Blue85]

You'll need to confirm that you have an open differential and not a gov-lock. If it's open, the "real" Detroit locker is basically a drop-in lunchbox, as you noted. What gear ratio do you have? It is possible to find a whole axle for less money than a locker, but you also need to factor in new U-bolts and whatever ever else the new axle needs (such as new brakes), or swap stuff off the old one.

 

[warrpath4x4]

cheapest welding, next cheapest a mini spool, next cheapest lunchbox is probably a spartan

 

[500$k5]

Yep! If you have an open carrier FF14, spend the money on a REAL Detroit locker! The FF14 is the only diff that the Detroit fits into the inside of the carrier. No gear setup needed!

 

[sweetk30]

https://ck5.com/forums/threads/14-bolt-full-float-carriers-i-d-info.151608/

 

[Chickntrk]

Weld it up into an orb of traction, only cost is time and welding wire.

 

[rampage]

Weld it up into an orb of traction, only cost is time and welding wire.

And tire wear if driven on the street.

 

[AZ79K5Project]

For a daily driver, the Detroit locker is a probably your best option. I ran the true lunchbox in a 12 bolt for a lot of years with only minor hiccups on 33’s. It grabbed one time during a sharp curve on a freeway. It did push me into the next lane, but that’s the only time it caught me off guard.

Depending where are are, the 14 bolts are becoming harder to come by with higher prices when they are listed.

 

[imiceman44]

So I'm revisiting the idea of changing my open rear diff to a locker or some sort.

I need to replace all the seals in the axle anyway, so I might as well do it all.

Whats the absolute cheapest way to get a locking rear diff? Amazon has them for $260, but I'm assuming its the wrong model for my rig.

78 K5, 8 lug, 14 bolt, FF. Anyone got a link to a cheap locker that would work? eBay? Amazon?

Am I better off just swapping the whole axle for a used one?

The cheapest you will find is $629 on Amazon.
I have a used one i could sell.
I could save you money