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Trutrack vs Air Locker vs Detroit for rear

ntsqd

heratic car camper
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Jan 30, 2005
Messages
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Upper SoKA
Ed Wong told me about 20 years ago that the way to drive a TruTrac with one tire in the air is to lightly modulate the brake pedal. A little bit of resistance added to the tire with no traction is all it takes to 'lock' that diff up.
 

bmc69

Contributor
Bronco Guru
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Jun 11, 2004
Messages
11,899
How does the TrueTrac react on a dirt road??..If I decide to spin it around real quick, drop the clutch and hit the gas what will happen??..Will both tires spin??

Yes, both will spin as if locked together. The torque bias capability of the TrueTrac is the highest I'm aware of out of all the limited slip designs. I have an Auburn in the Sterling in back of my '78 that comes close..but it's sure a noisy sucker. Screams and howls in protest when turning, especially in reverse.
 

Nothing Special

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Joined
Nov 25, 2016
Messages
838
No offense but if you have a stick shift you need to "work it"... :)

None taken. And I didn't say it was a big downside, just that it was the biggest.

And yes, in a front axle a selectable would be my first choice (and I'm planning to put an OX in the front of my Bronco this winter, time and money permitting). I'd also consider a TrueTrac in the front in a vehicle that wouldn't be rockcrawling. I'll never again put an automatic locker in a front axle (although I can imagine them being acceptable for only slow-speed crawling)


edit: Thinking about this more, no I don't need to "work" a stick shift, at least when it matters to me. When I'm on an obstacle (or series of obstacles) I never shift the transmission (except if I need to back up). So no, I don't need to "work" the trans on a trail when things are complicated. Likewise, I prefer not needing to worry about turning a locker on and off on obstacles.

That said, I still agree that it isn't really a big problem. No diff is perfect for everyone in all situations. Everyone needs to decide what trade-offs they want to make and which they don't want to make. For me the trade-off favors an automatic locker over a selectable in the rear, but a selectable over an automatic in the front. If your trade-offs are different you will prefer something else.
 
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Joe473

Sr. Member
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Jul 16, 2012
Messages
954
I know you guys are tired of seeing me start threads but my head is spinning. Fist of all I do NO rock climbing and 90% of the time she is on the road. What off roading I do is mainly trails/mud/sand. With that being said when I do go off roading I stay in 2 wheel drive just tooling around but have had to lock it in from time to time. I do pull a little boat and some boat ramps can be a little slippery but never had an issue with my limited slip. I am rebuilding my rear end and looking at different options. I have youtubed it to death and coming here for some Bronco buddy help. I want something better than the stock limited slip. And honestly the research I have done looks like Trutrack is the way to go.

351w on 35's
Based on yur use I would do true trac. It's a huge improvement over a factory limited slip. I've run it on the street light trails and sand with no issues. The rear true tracs do have some preload and yes a little e-brake drag will get you unstuck if one tire is in the air in 2wh drive. I also did a true trac up front. If yu do make sure you get the proper unit for for front d44. Less preload than a rear.

As a comparison I just bought a new f150 with open diff and active traction control. My opinion the true trac in my bronco works better.

Sent from my SM-G900V using Tapatalk
 
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kat

kat

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For some reason I can't get the video out of my head of a trutrac rear end with one tire on pavement and one on some wet grass and the thing just sat there and spins the tire in the grass. The more and more I think about it I like the idea of have both wheels spin all the time. Even though I do no rock crawling but I do trail/ditch/mud riding on occasion and all I can think about is going thru a mud hole and one tire falls in a rut and there I am...spinning wheels. Yes I know I have 4 wheel drive but normaly don't lock them in unless I know its going to be bad...
I don't ride on snow or ice and it seems that is the only bad street characteristics am I right??? Now if I speed down a dirt road will it get squirlly with me??? I am ready to pull the trigger on this before the weekend
 

bronconut73

Bronco Guru
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Aug 7, 2012
Messages
9,918
Besides....its fun to pull around the gas pumps when getting gas and having your locker clicking real loud making every body jerk the head around to look.
Its quite the "conversation starter".



Random Dork: "Hey Man there is something wrong with your Jeep, derrr..."

Me: "It's not a Jeep Hollywood"
 

Nothing Special

Sr. Member
Joined
Nov 25, 2016
Messages
838
Like I said, an automatic locker really isn't that bad on the street, so I'm not really trying to talk you out of one. But a TrueTrac is nowhere near that bad. It sends something like 3.5x as much torque to the tire on pavement as it does to the tire on wet grass in that situation. The wet grass has to be unbelievably slippery (and I mean that literally) for that to not work. And even if it is that slippery (like if it's on glare ice), as others have said, give it a couple of clicks of the e.brake. That'll make the slipping tire support more torque so the diff will send 3.5x that to the other tire.

For the rock crawling I do, where it's not uncommon to lift a tire in the air, I want the positive action of a locker. But for my hunting rig, that sees muddy and snowy trails as well as mostly good roads, the TrueTrac is definitely the best choice.
 
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kat

kat

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I just read that it can push and get a little loose in the rain on the street..Don't think that is a good idea. I am so confused. Maybe just go with everyone suggestions (and mine) Trutrac in the back
 

bronconut73

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Aug 7, 2012
Messages
9,918
I just read that it can push and get a little loose in the rain on the street..Don't think that is a good idea. I am so confused. Maybe just go with everyone suggestions (and mine) Trutrac in the back


It's a fine differential....and....

You can still call Random Dorks "Hollywood" if you want ...lol...
 

ntsqd

heratic car camper
Joined
Jan 30, 2005
Messages
3,631
Loc.
Upper SoKA
As I've mentioned, I drove a Detroit Locker on the street for 20 years, and I hated almost every pavement moment. I tended to forget it was even there in the dirt.

Don't know what video you saw, but that doesn't sound like TruTrac performance at all. Sounds like an open diff.
 

5001craig

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Nov 3, 2013
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1,180
I just read that it can push and get a little loose in the rain on the street..Don't think that is a good idea. I am so confused. Maybe just go with everyone suggestions (and mine) Trutrac in the back

Just like driving on ice, snow, etc... just have to be gentle with your right foot in those conditions. I can get my diesel Ram sideways when it's raining too--if I try.
 

Tucknkitty

Newbie
Joined
Nov 9, 2013
Messages
54
I know ntsqd mentioned it - it’s hard to beat an air locker or even the e-lockers. It really is the best of both worlds. Yes - the internet is filled with issues or complaints but if you find someone good to do the install you’re staring off on the right foot. The rest - electrical and plumbing is an easy afternoon.

Drive it like a normal truck with open diffs, on the street - rain - etc. lock it when you need it. Go anywhere.

*truth in lending: I have ARBs, I have had oil seeping from the compressor on hot days but no other issues.
 

Nothing Special

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Joined
Nov 25, 2016
Messages
838
I just read that it can push and get a little loose in the rain on the street..Don't think that is a good idea. I am so confused. Maybe just go with everyone suggestions (and mine) Trutrac in the back

Again, I do recommend a TrueTrac for your application, but I've never felt any "push" problems from an auto locker on the street. And they only get loose if you get on the gas enough to spin both back tires. Not that it's hard to get them loose like that, but if you're willing to "drive to the vehicle" it's easy to learn how to not have it get loose unless you want it to. (But I wouldn't recommend an auto locker for anyone who doesn't want to pay attention to the vehicle they drive).

You will squawk the inside tire starting around corners a lot. And when you get on or off the gas in turns you will feel some noticeable torque steer. In a CJ5 it will be bad enough for most passengers to comment. But in the bigger Bronco it's not nearly as noticeable.

Off road an auto locker in the rear will tend to increase your turning radius as it will push the front end straight more than other diffs. But I haven't seen that to be very significant very often either.
 

nvrstuk

Contributor
Just a Bronco driver for over 50 yrs!
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9,296
ARB's are the best...even tho I grenaded a 35 spline ARB case in half recently, I would recommend them over ANY other locker...

I can say that I've probably run them longer than anyone on this list...Feb '87 and I'm only saying this to give you some background that I've run these things for over 30 years now! nobody even knew what that "pssst" noise was when I hit the "unlock" button...but that doesn't matter, other than the fact that they have been #1 for decades for what they do and #1 for dependability...

That said, the selectable will ALLOW you to have a locked diff when when needed and you can hit a button and NOT slide sideways on an icy slippery sidehill like most automatic lockers will..example-Detroit... hit the skinny pedal to go forward when on a slippery, icy slope and you WILL go sideways... been there done that for a LONG time when running a Detroit...hated it...I wheel a LOT and this is what happens.

You can't feather the gas when both wheels are locked and not have them both spin. It's what physics demands...when that happens your rig slides sideways.

You can disengage the selectable and that now-non spinning tire acts as an anchor to keep you from sliding...

hope this helps some...
 
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kat

kat

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ARB's are the best...even tho I grenaded a 35 spline ARB case in half recently, I would recommend them over ANY other locker...

I can say that I've probably run them longer than anyone on this list...Feb '87 and I'm only saying this to give you some background that I've run these things for over 30 years now! nobody even knew what that "pssst" noise was when I hit the "unlock" button...but that doesn't matter, other than the fact that they have been #1 for decades for what they do and #1 for dependability...

That said, the selectable will ALLOW you to have a locked diff when when needed and you can hit a button and NOT slide sideways on an icy slippery sidehill like most automatic lockers will..example-Detroit... hit the skinny pedal to go forward when on a slippery, icy slope and you WILL go sideways... been there done that for a LONG time when running a Detroit...hated it...I wheel a LOT and this is what happens.

You can't feather the gas when both wheels are locked and not have them both spin. It's what physics demands...when that happens your rig slides sideways.

You can disengage the selectable and that now-non spinning tire acts as an anchor to keep you from sliding...

hope this helps some...
Damn yall gonna make me spend money;). I was going to get a complete third member with the trutrack already installed but if I drop down to an open carrier I save about $500...so (in my mind) the ARB wont be as expensive.
A couple quick questions.
1-Can you engage/disengage while moving??
2-Do I need a special ring gear/pinion or will my existing (open or limited slip) gears work???
 
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nvrstuk

Contributor
Just a Bronco driver for over 50 yrs!
Joined
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Messages
9,296
Yes, you can engage/disengage when moving...BUT you must be going straight as both wheels must be moving at the same speed or the obvious happens...things clash... it won't blow up but you know what it sounds like when you grind gears without the clutch.
 
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