Which posi unit do you like?

I'm restoring a 78 C10, it will never be raced but I want to go back with a posi. It has the stock 12 bolt with I believe 3:07 ratio. There's so many different units out there I'm just curious as to what some of you are running and how smooth they operate. I'm looking at Eaton Truetrac, Jegs clutch type posi unit, Yukon, and several others. I had a Cutlass with a 9" Ford with a Detroit Locker and it was smooth and hooked every time, it did get raced but the truck won't be but I still want something that can take a beating just in case. There's also a gear type that I'm not familiar with but I hear they are noisy, I don't want noise. Any suggestions? Thanks.

I have used the Detroit True Trac as well as a Yukon Dura Grip.

I did have to replace the Detroit due to a later bent axle tube putting weird pressure on the internal gear set causing it to destroy itself.
But I would not hesitate to install another one.
Mine was aggressive as you could hear the inside tire scrubbing as I turned out of my driveway.
It never left me stranded, just broken in the driveway once I opened the cover and saw the metal bits in the bottom.
They are not rebuildable and parts for them are not available.
Mine would most likely still be good had we not lost that tire while on the road thus bending the tube up...
The unit it self is absolutely quiet, you would never know it is in there if you didn't know it was.

Here is the axle at the axle dudes shop with the True Trac still installed...

On the bench disassembled...

Blammo!
This ruined my day and ate up a bunch of my money when I didn't want it too...



The Yukon has replaced the Detroit as it was less expensive at the time and the rear end guy has put many of them into many axles.
It works like a champ as well and I have not experienced any missing traction since it was put in a couple years ago.
It is not anywhere as aggressive as the previous one, but it still works like a champ.
Plus this one is rebuildable.

New unit ready to go into service.


Set and ready to go.



Both work quite well and I would recommend either.

I got everything for my 10-bolt through Quick Performance, they support tons of different axles and have the best deals out there IMO. I have the Yukon Duragrip in my truck (~425hp 5.3, T56, 3.90 gears), it's a clutch type so it's quiet and operates very smoothly but locks every time I put the power down. I really like this unit.

I just bought a yukon yesterday from Amazon for like $240~, from the Amazon store. Not a 3rd party. They might still be on sale, I'll check when I get out of work later today.

Just some opinion here based on my own meandering experience. My ‘80 K25 has a Detroit locker in the rear and a TruTrac upfront. My ‘73 C20 has the factory locking diff (RPO G86, it’s not a G80 locker), which is a clutch pack style limited slip.

My ‘80 K25 is my work horse and off road truck so the Detroit locker serves its purpose and does great off road. You can go a lot further off road in 2WD before shifting into 4WD than you could with an open diff or G80. The con is screeching around turns on pavement, maneuvering in parking lots, etc. You can feel it banging in and out of lock up. I’m very happy with it in that truck, but 0 out of 10 wouldn’t recommend it if your truck is going to be a pavement princess.

Since the TruTrac is in my front axle I don’t experience it except in 4WD, but when it’s engaged it’s smooth and quiet. You don’t feel it ‘kick in’ since it’s constantly working.

The clutch pack G86 locking diff in my ‘73 C20 is great. Being 2WD it’s doesn’t see much off road. It’s quiet and smooth. You don’t even know it’s there until you’re slipping on ice, gravel, or whatever and it suddenly kicks in when you need it. If I was to install a posi unit into a car or truck meant for pavement, which I am looking into for my wife’s ‘66 Mustang coupe, I would go with a clutch pack style. I don’t have a particular brand preference. I would ask around, read reviews, and do my research before choosing a brand, but that’s the route I’d go.

Yukon dura grip in my 79 12 bolt and in my friends 14b SF we built for his K5.

Catbox said:

I have used the Detroit True Trac as well as a Yukon Dura Grip.

I did have to replace the Detroit due to a later bent axle tube putting weird pressure on the internal gear set causing it to destroy itself.
But I would not hesitate to install another one.
Mine was aggressive as you could hear the inside tire scrubbing as I turned out of my driveway.
It never left me stranded, just broken in the driveway once I opened the cover and saw the metal bits in the bottom.
They are not rebuildable and parts for them are not available.
Mine would most likely still be good had we not lost that tire while on the road thus bending the tube up...
The unit it self is absolutely quiet, you would never know it is in there if you didn't know it was.

Here is the axle at the axle dudes shop with the True Trac still installed...

You must be registered for see images attach

On the bench disassembled...

You must be registered for see images attach

Blammo!
This ruined my day and ate up a bunch of my money when I didn't want it too...

You must be registered for see images attach

The Yukon has replaced the Detroit as it was less expensive at the time and the rear end guy has put many of them into many axles.
It works like a champ as well and I have not experienced any missing traction since it was put in a couple years ago.
It is not anywhere as aggressive as the previous one, but it still works like a champ.
Plus this one is rebuildable.

New unit ready to go into service.

You must be registered for see images attach

Set and ready to go.

You must be registered for see images attach

Both work quite well and I would recommend either.

Click to expand...

Thanks much for the info. The Yukon is sounding like the one.

K10eddie said:

Amazon.com

Click to expand...

Thanks much for the info. That's prob the one I'll go with. Several others like it as well. I was looking at the Jegs clutch unit with the yellow springs but the Yukon is cheaper and if it's holding up for you guys it will work fine for me.

Catbox said:

I have used the Detroit True Trac as well as a Yukon Dura Grip.

I did have to replace the Detroit due to a later bent axle tube putting weird pressure on the internal gear set causing it to destroy itself.
But I would not hesitate to install another one.
Mine was aggressive as you could hear the inside tire scrubbing as I turned out of my driveway.
It never left me stranded, just broken in the driveway once I opened the cover and saw the metal bits in the bottom.
They are not rebuildable and parts for them are not available.
Mine would most likely still be good had we not lost that tire while on the road thus bending the tube up...
The unit it self is absolutely quiet, you would never know it is in there if you didn't know it was.

Here is the axle at the axle dudes shop with the True Trac still installed...

You must be registered for see images attach

On the bench disassembled...

You must be registered for see images attach

Blammo!
This ruined my day and ate up a bunch of my money when I didn't want it too...

You must be registered for see images attach

The Yukon has replaced the Detroit as it was less expensive at the time and the rear end guy has put many of them into many axles.
It works like a champ as well and I have not experienced any missing traction since it was put in a couple years ago.
It is not anywhere as aggressive as the previous one, but it still works like a champ.
Plus this one is rebuildable.

New unit ready to go into service.

You must be registered for see images attach

Set and ready to go.

You must be registered for see images attach

Both work quite well and I would recommend either.

Click to expand...

Wow, that really sux. Thanks for all the pics and info. I'll go with Yukon...

K10eddie said:

I just bought a yukon yesterday from Amazon for like $240~, from the Amazon store. Not a 3rd party. They might still be on sale, I'll check when I get out of work later today.

Click to expand...

That would be great, thank you.

I've had a Detroit locker in my 14 bolt on my K20 for years. It has about 11k miles of hard use on it, I go to the dunes a lot with it. It hooks like crazy but it did take some getting used to, I have 33" mud tires and if I'm driving curvy back roads in the rain I go easy through the curves.

My son has a TrueTrac in his 08 Silverado. God forbid if or when my locker ever breaks that's probably the route I'll go just because you don't even know it's there until you stomp the gas in the sand or mud and both wheels bite. I just got a TrueTrac for my front diff but haven't installed it yet.

Based on this, I'd say for a driver get a TrueTrac, if you race it on or off-road get a Detroit locker.

My extremely experienced mechanic is a fan of Auburn limited slips. Yep.. you get what you pay for.

Dezzracer said:

My extremely experienced mechanic is a fan of Auburn limited slips. Yep.. you get what you pay for.

Click to expand...

Those are actually quite a bit cheaper than a TrueTrac. I don't have any experience with them, only saing that because I don't understand the "get what you pay for" comment. An Auburn for a Dana 44 is about $415, whereas a TruTrac is about $650.

I purchased the TrueTrac from East Coast Gear Supply. Based solely on research. Haven't installed yet. I have a Detroit Locker in my 4x4 but you can hear it when disengaging and is harry on slick roads till you get used to it.