Yukon Posi vs Detroit TruTrack

[hunters628]

Hey Hunter you live in my neck of the woods, and welcome. I installed a lunchbox locker in my 14 bolt, Yukon, and detail it on my build page. Blew up the TH350 with the 454, but the rear end is great. I was wondering what year your truck was, as my 73 K10 has a posi 12 bolt rear and ten bolt front. If you would like welcome to come look at my stuff, look at the thread, gain some knowledge, and make a informed decision. The truck 12 bolt has the small pinion support bearing, so not as strong as the car 12 bolt. However, this truck has NEVER had a problem with the rearend, (stock posi) has probably 100,000 off road miles, hauled many ridiculously overloaded loads, puller a hay trailer consistently with 8000+ still going. The 14 bolt is much better choice if you want to haul heavy loads IN THE BED, as it is a full floater, (ff). I just looked on marketplace, and craigs list, lots of complete, or parting out's there reasonable.


https://www.gmsquarebody.com/threads/1973-k20-350-to-454-swap.29840/

Craig that’s a good looking truck you got there. Also good to see you made it through Evans Canyon. That was one hell of a week. My truck is an 82 with factory front and rear 10 bolts and 3.08 gears. Not gonna be too good with 33 inch tires and a th400! I’m not gonna be hauling anything with the truck as I have other rigs for that. This will mainly be a daily driver.

 

[SquareRoot]

Before you buy new, look for a 14 bolt with a locker already in it. You could find one that will cost less than a new locker and have a real man's diff instead of the wimpy 10 or 12 bolt whatever is in your truck. Sounds like you might want to move up a tire size or two, so look for that 14 bolt with your
lower ratio in mind. Then you'll want even bigger tires and may as well slide D60 up front. Then comes the big block!

And the posts about improving gas mileage.....

 

[Bextreme04]

Craig that’s a good looking truck you got there. Also good to see you made it through Evans Canyon. That was one hell of a week. My truck is an 82 with factory front and rear 10 bolts and 3.08 gears. Not gonna be too good with 33 inch tires and a th400! I’m not gonna be hauling anything with the truck as I have other rigs for that. This will mainly be a daily driver.

Not sure how far away you are from Graham, but I just saw a Square body 12-bolt 6 lug with 4.11's and posi for sale in Graham,WA for $400

 

[Craig Nedrow]

Craig that’s a good looking truck you got there. Also good to see you made it through Evans Canyon. That was one hell of a week. My truck is an 82 with factory front and rear 10 bolts and 3.08 gears. Not gonna be too good with 33 inch tires and a th400! I’m not gonna be hauling anything with the truck as I have other rigs for that. This will mainly be a daily driver.

I would run the stock trans, and axles. TH400 is very strong, 3:08 nice highway gears, and that 305 sure not gonna break a 8.5 ten bolt, which is what yours is. Save a lot of time and money.

 

[hunters628]

I would run the stock trans, and axles. TH400 is very strong, 3:08 nice highway gears, and that 305 sure not gonna break a 8.5 ten bolt, which is what yours is. Save a lot of time and money.

The truck has a 5.3 ls in it now. But still doesn’t make too much power. I’ll be keeping it stock and with the power loss through the th400 it’ll be about same power as a 305. Thanks for the advice Craig.

 

[Swearbody]

For as long as i can afford it, ill put grizzly lockers in every damn solid axle i own.

https://eastcoastgearsupply.com/c-977002-lockers-grizzly-lockers.html
**** detroits, **** tru trac lol

I clicked the link and they dont show they sell a grizzly for 10 bolt's. I was gonna see what the deal was. So between the two truetrac is still the way to go.
What did you mean by the detroit trutrac not unlocking in turns....I didnt know that was a thing.

 

[Vbb199]

I clicked the link and they dont show they sell a grizzly for 10 bolt's. I was gonna see what the deal was. So between the two truetrac is still the way to go.
What did you mean by the detroit trutrac not unlocking in turns....I didnt know that was a thing.

Weird. I was sure i saw them for 10 bolts on the innerwebz.

A detroit locker is a harsh, mechanical locker LIKE the grizzly locker, except the grizzly locker does not require you to let off of gas and stop steering when you want it to unlock..... the grizzly will unlock itself on turns and DOESNT produce whats known as torque steer like the detroit locker does.

Between the trutrac and grizzly, i believe the tru trac applies power to the opposite tire thats got traction when 1 tire spins. (I.e. your pass tire spins in the ditch, power is applied to the driver tire), i dont think that classifies as a locker, but rather a limited slip?

The grizzly sees a difference in tire speed, and like a detroit, locks in like a spool.
It IS a locker, but the exception is, the thing doesnt fight your steering wheel, and you dont have to let off the power to make it unlock. It was like it wasnt even there on my last offroad experiences.

From what ive gathered the truetrac doesnt apply 100% torque to the tires, whereas the grizzly or detroit does.
But does any of this REALLY matter if you cant find it for a 10 bolt?? Lolz

 

[Swearbody]

Weird. I was sure i saw them for 10 bolts on the innerwebz.

A detroit locker is a harsh, mechanical locker LIKE the grizzly locker, except the grizzly locker does not require you to let off of gas and stop steering when you want it to unlock..... the grizzly will unlock itself on turns and DOESNT produce whats known as torque steer like the detroit locker does.

Between the trutrac and grizzly, i believe the tru trac applies power to the opposite tire thats got traction when 1 tire spins. (I.e. your pass tire spins in the ditch, power is applied to the driver tire), i dont think that classifies as a locker, but rather a limited slip?

The grizzly sees a difference in tire speed, and like a detroit, locks in like a spool.
It IS a locker, but the exception is, the thing doesnt fight your steering wheel, and you dont have to let off the power to make it unlock. It was like it wasnt even there on my last offroad experiences.

From what ive gathered the truetrac doesnt apply 100% torque to the tires, whereas the grizzly or detroit does.
But does any of this REALLY matter if you cant find it for a 10 bolt?? Lolz

which sucks cause that sounds like a dream come true. From what ive gathered the trutrac WILL apply 100% as long as both tires are on pavement. The trutrac acts up when one tire is off the ground or unloaded aka...offroad. Also they are designed to unlock when turning and are sold as a Limited Slip. Offroaders hate em but the pavement pounders seem to love them. I have a 2wd and will mostly be on pavement. I kinda like the idea of helical gears vs clutch packs but I also have only ever had stock posi units(clutch packs)
I dunno though. Never drove a truck with a trutrac

 

[Vbb199]

which sucks cause that sounds like a dream come true. From what ive gathered the trutrac WILL apply 100% as long as both tires are on pavement. The trutrac acts up when one tire is off the ground or unloaded aka...offroad. Also they are designed to unlock when turning and are sold as a Limited Slip. Offroaders hate em but the pavement pounders seem to love them. I have a 2wd and will mostly be on pavement. I kinda like the idea of helical gears vs clutch packs but I also have only ever had stock posi units(clutch packs)
I dunno though. Never drove a truck with a trutrac

If its staying on the road, i imagine it'll be fine, i believe i might've misunderstood and thought you were doing some offroad and on road action in a 4x4.
Wasnt aware you had a c10

I read people saying the grizzly locker would spit teeth on a big tire, big hp app.
My 4.3 makes like, 2-250hp, and im running 39.5x15 wide boggers on it. Its not enough ass to bust anything.

I see no value in a truetrac in a offroad app. And im naturally offroad minded, i would personally only run a detroit in a big tire, big HP, big axle offroad application, like my k5 with a 502, 53" tires, and 5 tons. (I have one in the front axle)

Putting a detroit in 10 bolt seems suicidal might as well weld the spider gears and save yourself the money, its gonna break anyways

 

[Craig Nedrow]

I clicked the link and they dont show they sell a grizzly for 10 bolt's. I was gonna see what the deal was. So between the two truetrac is still the way to go.
What did you mean by the detroit trutrac not unlocking in turns....I didnt know that was a thing.

Vince, you are right, Yukon does not have a locker for that application, However, US gear makes a lunchbox locker that will fit an open diff 28 spline or 30. you can go here:

https://www.randysworldwide.com/diff-wizard/?diffyear=1986&make=Chevrolet+/+Chevy&model=K10/+K1500+1/2+Ton+(4WD)&drivetype=Front+Diff+-+4WD&diffid=212

Many youtube videos here:

https://www.youtube.com/results?search_query=spartan+lunchbox+locker+

All gear, and no clutches. I have four clutch type LS, and without fail, they will need to be rebuilt, hence why I am moving to the gear lockers. My bro has a 65 Plymouth Satellite with a 496, 600 tire HP, 8.75 chrysler drop out with the Eaton gear type. Expensive but excellent.

 

[hunters628]

If its staying on the road, i imagine it'll be fine, i believe i might've misunderstood and thought you were doing some offroad and on road action in a 4x4.
Wasnt aware you had a c10

I read people saying the grizzly locker would spit teeth on a big tire, big hp app.
My 4.3 makes like, 2-250hp, and im running 39.5x15 wide boggers on it. Its not enough ass to bust anything.

I see no value in a truetrac in a offroad app. And im naturally offroad minded, i would personally only run a detroit in a big tire, big HP, big axle offroad application, like my k5 with a 502, 53" tires, and 5 tons. (I have one in the front axle)

Putting a detroit in 10 bolt seems suicidal might as well weld the spider gears and save yourself the money, its gonna break anyways

Like I said before, this truck will be 90% town and freeway. The only off road driving I do is heavily driven trails that are usually gravel with about 6 inches of snow on top. That’s kinda why I was leaning towards a TrueTrac. I would like to just get the G80 out of there because I know they have a reputation for leaving people stranded.

 

[Swearbody]

If its staying on the road, i imagine it'll be fine, i believe i might've misunderstood and thought you were doing some offroad and on road action in a 4x4.
Wasnt aware you had a c10

I read people saying the grizzly locker would spit teeth on a big tire, big hp app.
My 4.3 makes like, 2-250hp, and im running 39.5x15 wide boggers on it. Its not enough ass to bust anything.

I see no value in a truetrac in a offroad app. And im naturally offroad minded, i would personally only run a detroit in a big tire, big HP, big axle offroad application, like my k5 with a 502, 53" tires, and 5 tons. (I have one in the front axle)

Putting a detroit in 10 bolt seems suicidal might as well weld the spider gears and save yourself the money, its gonna break anyways

The shop thats doing the work has a good reputation for backing their work(which i know has recently bit me in the ass on that motor i have) and gives a 1 year warranty on parts and labor IF THEY INSTALL IT AND PICK THE PARTS. Admittedly They are by far the most expensive shop in town but its worth it for the peace of mind. They seem to think its the way to go for my application. If i cant break it in a year then its probably pretty alright. I asked how they could afford to warranty them so well and was told they only do labor warranties on oe equipment and my truck wasnt built enough to deny the claim....kinda got butthurt but whatever,LOL
I have never ever paid anyone to do work on something ive owned....not the truck,car,house,plumbing,electrical,hvac etc....It just never felt right what with me having two hands and all. THIS however i am working into a deal on a sxs and its gonna end up costing me like 300 bucks by the time i make my $$ off the sxs sale.

 

[Vbb199]

The shop thats doing the work has a good reputation for backing their work(which i know has recently bit me in the ass on that motor i have) and gives a 1 year warranty on parts and labor IF THEY INSTALL IT AND PICK THE PARTS. Admittedly They are by far the most expensive shop in town but its worth it for the peace of mind. They seem to think its the way to go for my application. If i cant break it in a year then its probably pretty alright. I asked how they could afford to warranty them so well and was told they only do labor warranties on oe equipment and my truck wasnt built enough to deny the claim....kinda got butthurt but whatever,LOL
I have never ever paid anyone to do work on something ive owned....not the truck,car,house,plumbing,electrical,hvac etc....It just never felt right what with me having two hands and all. THIS however i am working into a deal on a sxs and its gonna end up costing me like 300 bucks by the time i make my $$ off the sxs sale.

Same. Ive always done my own **** (same as what you listed)
Im recently learning to do transmissions. To add to the resume.

That and axle regears and locker installs.
All successes so far.

Obviously helps that i have the keys to a full blown machine shop dowm the driveway (my work)
I can precision machine and measure anything i need which puts me at an advantage over most typical trans and rear end shops.

 

[Swearbody]

Same. Ive always done my own **** (same as what you listed)
Im recently learning to do transmissions. To add to the resume.

That and axle regears and locker installs.
All successes so far.

Obviously helps that i have the keys to a full blown machine shop dowm the driveway (my work)
I can precision machine and measure anything i need which puts me at an advantage over most typical trans and rear end shops.

Yeah id say thats an advantage. I have an open carport and a measuring tape,LOL. Never done an auto trans though. hope i never have to but i am rockin a 700r4 so whatchout.

 

[SquareRoot]

I swapped out the OEM axles on my 85 K20 for a set of NOS CUCV axles awhile back. I had to move spring perches and such but no big deal. The rear is a 14FF with the Detroit Locker/4:56 gears.

For months afterwards I'd get an occasional gawd awful bang in the drivetrain that would feel like I got rear-ended. I'd go home and check for loose spring mounts, u-joints, anything suspension related.

Then I did a bunch of research and discovered the Detroit Locker is also called the Detroit Bang Bang-

Yes sir, its normal operation on hard surfaces. It doesn't happen much but it gets your attention when it does. I also did some serious 4xing recently on some narrow ridgetops that was made by four wheelers and side by sides. More than once I only had 2 or 3 wheels touching the ground. I was impressed and humbled by the performance of that locker.

I wouldn't change it for the world.