Detroit Locker

[GreatDaneHummer]

Is anyone running a Detroit Locker in the rear of their H3?

 

[06 H3]

Yep I am...

 

[Jack_M]

Yeah but your changed out your axles didn't you 06 H3? If not curious as to what model your using!

 

[06 H3]

Yea I am running a Ford HP Dana 44 front and Eaton HO72 rear. I always thought that detroits would suck but when my buddy installed one in his TJ I went for a ride and you can't feel it on the street. When I put mine in same thing...if you punch it in a U turn you will chirp a tire but even complete 180 turns if your moderate on the throttle you don't feel it. I'm not in snow so I can't say how they do in the snow but for me it works great and I was pleasantly surprised

 

[5gn-h3t]

I've never had one in an H3 but have had them in other vehicles and have grown to really hate them. On the street they always seem to lock at the wrong time. They are pretty good off-road but I really hate the street manners. Sometimes the vehicle will roll a little when you put it in park. Personally, I would only go with a selectable locker on an H3.

 

[06 H3]

It's funny you say that, I feel like most people HATE Detroit lockers or LOVE them. There is no in between. I do feel that some vehicles are more sensitive to them. It can be 2 identical vehicles with the same Detroit locker and one is more sensitive then the next. I'm not sure what it is. I've had luck with mine. I do want to get some reviews on it personally in the snow. I'm gonna have to make a trip up to the mtn towns sooner then later

 

[4speedfunk]

The new worm drive Eatons (called "Detroit True Trac") are awesome. They work completely different from traditional Detroits...totally smooth and predictable. Take those ratcheting old school units from the 70s and toss em.

I still prefer selectables on my H3.


Sent from my iPhone using Tapatalk

 

[Mb30sdl]

I agree with speedfunk rear wasn't to bad in gmc but front was pulled out with in couple of weeks.

 

[GreatDaneHummer]

I had an opportunity come up to buy this Detroit Truetrac for the rear for $100 and I went ahead and grabbed it. So before I spend the time and money putting it in just wanted to know if it was worth it. Thanks 4speed! I will go ahead and drop it in. If I get any more snow I will post up something 06 but I think we are done for the winter here in Chicago.

The new worm drive Eatons (called "Detroit True Trac") are awesome. They work completely different from traditional Detroits...totally smooth and predictable. Take those ratcheting old school units from the 70s and toss em.

I still prefer selectables on my H3.


Sent from my iPhone using Tapatalk

 

[4speedfunk]

The Detroit True Trac is what all the muscle car guys use. For that kind of application it works great (where you stomp the throttle and try to get tires to hook). The DTT gets activated by throttle and there are worm gears that tighten up the two halves and thus lock it solid. Upon coast or turning...they un-thread and release the unit. If you stab the throttle in a turn, it will go solid instantly and smoothly, and release just as easy. The throttle activates it. So when turning or at very low input from the throttle...it probably won't lock, unless one tire spins. Regardless these are great units, and I don't know anyone that has broke one.

The old original Detroit locker works completely opposite from this. It is locked all the time and only releases when the pressure exerted on the shafts overcomes the internal rachetting mechanism. Because of this, these diffs will often "click" or "pop" in corners, when the teeth rotate past each other. They never really "unlock"...they simply get overcome by turning and jump to the next tooth. They are not smooth and they often cause your vehicle to wander back & forth at highway speeds...as if it had a spool. The plus side is...they are not dependent on throttle input. IMO...these are like points ignition, cassette tapes, or white-out. There are better devices nowadays.

Since selectables are controlled by you, the driver...they can be shut on/off at all speeds and all load situations. This includes creeping, idling, turning, full or part thottle, etc. You can activate your selectable (ARB, Eaton E-locker, Ox, etc.) and it will stay locked no matter how tight the turn or how slow the speed. This is why off-roaders like selectables. An automatic engaging unit cannot do this. Its either throttle dependent (DTT), or stuck in the ON position all the time (Detroits, Gov locks, posi's, limited slips, etc.), until turning forces overcome whatever type of mechanism they use. Sometimes they put you situations you don't want (up against a tree), and its nice to be able to go "open" diffs with the push of a button.

BTW...There was an Eaton E-locker (8.5/8.6 10b) on ebay a couple weeks ago for $300...about a third of retail.

 

[GreatDaneHummer]

For the front I did the ARB air locker. I guess I just went cheap with the $100 rear locker for now. If it sucks I can always upgrade to the ARB in the rear too when funds permit.

 

[atvspeed4]

For the front I did the ARB air locker. I guess I just went cheap with the $100 rear locker for now. If it sucks I can always upgrade to the ARB in the rear too when funds permit.

If you end up wanting to go ARB route let me know I would love to buy the trutrac for my DD alpha. I think you may be disappointed in its performance as a limited slip for rock crawling as it requires application of the brakes to transfer torque when one wheel is in the air (like the torsen in the H1).

 

[Schwarttzy]

My vote is for the Detroit Tru-Trac http://www.eaton.eu/Eaton/ProductsServices/Vehicle/Differentials/detroit-truetrac/index.htm

When I had my ridiculous ZJ Grand Cherokee with full 6.5" long arm suspension it was amazing. Very little brake pressure was need to activate.

Tru-Trac is a torque sensitive locker, where as a Detroit locker is speed sensitive. In the snow, ice, and deep mud the Tru-Trac is unbeatable.

I'm work on a new project for my H3 and I will be using a Tru-Trac up front.

 

[GreatDaneHummer]

Maybe I will like the one in the rear then. Lets hope. The ARB in the front is a done deal with the SAS so it would be nice to see how this setup goes when all things are said and done.

 

[3Hummers]

I had a Detroit in the rear on my 98 H1. HATED it. Chirped on turns, chewed up the splines on the half shafts. What a POS.

 

[USMC_TOP]

I put a Detroit Locker in my 87 1 ton Silverado and loved it on and off road on 38's and 500hp


Sent from my iPhone using Tapatalk

 

[4speedfunk]

I have a Dana44 front axle for an upcoming SAS on my Burb...its got a Yukon Grizzly in it. Thought I would give it a try.


Sent from my iPhone using Tapatalk

 

[Burtor]

My vote is for the Detroit Tru-Trac http://www.eaton.eu/Eaton/ProductsServices/Vehicle/Differentials/detroit-truetrac/index.htm

When I had my ridiculous ZJ Grand Cherokee with full 6.5" long arm suspension it was amazing. Very little brake pressure was need to activate.

Tru-Trac is a torque sensitive locker, where as a Detroit locker is speed sensitive. In the snow, ice, and deep mud the Tru-Trac is unbeatable.

I'm work on a new project for my H3 and I will be using a Tru-Trac up front.

Could you talk more about the TruTrac up front? I've been interested in learning about that, particularly why this TruTrac will or will not just bolt right in the front.
Eaton TrueTrac - GM 7.5" and GM 7.625" 28 Spline (3.23 & Up)
https://www.drivetrainshop.com/Detroit_TrueTrac_p/eat-912a317.htm

It's got a lot of the right numbers going for it, but I've not yet heard of anyone trying it or doing it yet.
I mean, when I compare the compatibility lists with the ARB air locker, there's enough similarities that I can almost talk myself into the idea that it would just work.
ARB Air Locker - GM 7.5" and GM 7.625" 28 Spline (RD148)
https://www.drivetrainshop.com/ProductDetails.asp?ProductCode=ARB-RD148

 

[4speedfunk]

Who said it won't bolt up? Should fit with no issues. The AAM-7.625 IFS is basically the GM 7.5 10-bolt rear axle flipped around and spinning in reverse. This diff was used in lots of Malibus, Camaros, Monte Carlos, S-10s, etc....all thru the late-70s & 80s. The H3 uses the same ring & pinion and 28-spline differential as all these vehicles...but the bearings and obviously the IFS housing are different.

Even though it fits...the bigger issue might be how nice the automatic locker plays with the Stabilitrac electronics.

 

[Burtor]

Who said it won't bolt up? Should fit with no issues. The AAM-7.625 IFS is basically the GM 7.5 10-bolt rear axle flipped around and spinning in reverse. This diff was used in lots of Malibus, Camaros, Monte Carlos, S-10s, etc....all thru the late-70s & 80s. The H3 uses the same ring & pinion and 28-spline differential as all these vehicles...but the bearings and obviously the IFS housing are different.

Even though it fits...the bigger issue might be how nice the automatic locker plays with the Stabilitrac electronics.

That'a really awesome to hear, I've always thought it was cool the way that the Humvee had Torsen/Tru-Trac lockers on both diffs and I've been wanting to do it to my H3.

Are there any builds you know of where someone has bought that Eaton 912A317 and stuffed it into the front?

Regarding the stabilitrac electronics I would expect zero issues. For as advanced as it is, I believe it's actually a pretty 'dumb' system. As far as I know, the only inputs to the system are the wheel speed sensors (abs) so if the differential is preemptively catching slip then the stabilitrac doesn't have to step in, or even know that it should.
This I think is contrasted to something like the Audi quattro system which couples input from steering wheel position, yaw sensors, wheel speed sesnors, and accelerometers all to work together to apply just the right amount of braking on each wheel to keep your car going straight. It looks like a number of the Audi systems use torsen diffs as well.
In fact, the weak point of the Tru-Trac differential is when one wheel is completely lifted, in which case the stabiltrac is supposed to apply some braking to the lifted wheel, then the Tru-Trac would only help transfer more of that torque to the other wheels, with less braking force required.

Anyway, I'll be doing some more research before pulling the trigger on this sort of thing, but it might be sooner rather than later, looks like there's a mfg rebate happening for Eaton stuff through March.
Front: Tru-Trac 7.5" 28 Spline - $369 (After rebate)
https://www.summitracing.com/parts/dtl-912a317
Rear: Tru-Trac 8.5" 30 Spline - $389 (After rebate)
https://www.summitracing.com/parts/dtl-913a481

 

[4speedfunk]

Yeah...I think for 95% of normal driving, a tru-trac would work fine with the Stabilitrac. But that other 5%...I can see where the puter might try to fight the tru-trac or visa-versa. I'm talking about 50 mph, drifting sideways thru a sweeping corner on a gravel road. Or also possibly on snow/ice. Whenever the stabilitrac is fully activated and trying to keep you pointed in the right direction, the tru-trac might interfere. I have no real proof...its just a hunch I have.

I say this because unlike all the other GM truck offerings...the H3 never came with any sort of automatic locking diff (ie: posi, gov-lok, limited slip, etc.). This makes me think there might be a problem with running one. Also, notice that the H3 comes from the factory with interlocks that limit when you can and cannot use the lockers...and this is also tied to the Stabilitrac system. You cannot engage the lockers in anything but low-range. And this also just happens to be the only mode where the Stabilitrac is defeated. So you cannot engage lockers and Stabilitrac at the same time. As soon as you shift out of low range...the lockers are defeated, and Stabiltrac is activated. I don't know if this is coincidence, or if GM specifically wired the factory lockers this way for a reason. Perhaps Stabilitrac needs full (unlimited) slip to function properly? I honestly don't know, and I'm not going to drop a couple grand to experiment and find out.

That being said...many of us (including me), have installed front lockers that are wired and controlled independently of any computer over-rides. Also...06H3 runs an auto-locking rear diff with no issues. Whatever issue it might cause may be so slight that you would never notice it. It might be so slight that all you notice is shorter brake pad life. Whatever the case (Stabilitrac issues or not)...nearly all off-roaders prefer selectables over automatic diffs because they are so much more predictable and controllable, especially at low (crawling) speeds and on slick surfaces. I have been in many situations where a locked axle would have meant TREE DENT! Its nice to be able to shut them off when you want to.

Lastly...if you do try the Tru-Trac in the AAM-7.5 IFS, please post your findings!

 

[atvspeed4]

Yeah...I think for 95% of normal driving, a tru-trac would work fine with the Stabilitrac. But that other 5%...I can see where the puter might try to fight the tru-trac or visa-versa. I'm talking about 50 mph, drifting sideways thru a sweeping corner on a gravel road. Or also possibly on snow/ice. Whenever the stabilitrac is fully activated and trying to keep you pointed in the right direction, the tru-trac might interfere. I have no real proof...its just a hunch I have.

I say this because unlike all the other GM truck offerings...the H3 never came with any sort of automatic locking diff (ie: posi, gov-lok, limited slip, etc.). This makes me think there might be a problem with running one. Also, notice that the H3 comes from the factory with interlocks that limit when you can and cannot use the lockers...and this is also tied to the Stabilitrac system. You cannot engage the lockers in anything but low-range. And this also just happens to be the only mode where the Stabilitrac is defeated. So you cannot engage lockers and Stabilitrac at the same time. As soon as you shift out of low range...the lockers are defeated, and Stabiltrac is activated. I don't know if this is coincidence, or if GM specifically wired the factory lockers this way for a reason. Perhaps Stabilitrac needs full (unlimited) slip to function properly? I honestly don't know, and I'm not going to drop a couple grand to experiment and find out.

That being said...many of us (including me), have installed front lockers that are wired and controlled independently of any computer over-rides. Also...06H3 runs an auto-locking rear diff with no issues. Whatever issue it might cause may be so slight that you would never notice it. It might be so slight that all you notice is shorter brake pad life. Whatever the case (Stabilitrac issues or not)...nearly all off-roaders prefer selectables over automatic diffs because they are so much more predictable and controllable, especially at low (crawling) speeds and on slick surfaces. I have been in many situations where a locked axle would have meant TREE DENT! Its nice to be able to shut them off when you want to.

Lastly...if you do try the Tru-Trac in the AAM-7.5 IFS, please post your findings!

I am confident that the trueTrac will work excellent with the H3 traction control system/ stability trac. It was made to work with vehicles with these systems and will not distribute torque to the opposing wheel without torque input from the driveshaft. So in an instance of a highspeed slide where you are trying to correct and press the brakes, the diffs will function as if they are open as they are not receiving torque. There are so many vehicles that run a gear driven limited slip with traction control. The ford raptor is one of them. I will be running a Truetrac in my DD alpha H3 front and rear shortly but using our custom front housing.

If anyone has access to a open carrier for a 7.5/7.6 rear GM diff I can compare to the front AAM carrier out of our 2006 that is sitting on the shelf. That is probably the cheapest way to solve this mystery.