full time and detroit?

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CharlieS said:
Still trying to figure out whay an aussie locker wouldn't be a bad idea for my street driven (and some primitive dirt road driving) 80...

Let's turn that question around. Unless you are getting stuck at the mall or on these dirt roads, why do you think you need upgraded differentials and the tradeoffs that come with them?

Nay
 
semlin said:
charlie

an automatic locker would not by itself disable the fulltime 4wd system, but I think most folks would not want to drive with one in a DD on the street especially in wet or ice? John is thinking of switching to part time 4wd if he installs an auto locker for this reason, and others have replied to him on the basis he will be doing that if he goes with an auto-locker.

.

NO That is not correct.

I have driven full time, detroit rears and limited slip fronts for years on the street. There is NO detrament, except on shear ice, like from an ice storm, and in that case your are fawked regardless. My FJ is currently running a detroit on the rear now. all you do is scrub tires a little more.

Sometimes you have to think outside the box.
 
John

ok, well going back to your very first post, why do you want part time front hubs on the front so you "can still drive the 80 on the street". If it's not for economy and it's not to keep the locker inactive on the street, I am totally lost. I have no personal experience with detroits but I have certainly heard complaints from folks who have them about the way they can sometimes behave on the street and some of what I have heard goes beyond chirping tires. I just assumed that avoiding that problem was your motivation given what you said at the beginning of this thread and in another thread.

I guess I have been doing some assuming about what you know, and why you are doing stuff. sorry about that. Rick/Landtoy is right that we do not have a lot of experience with auto-lockers here.
 
semlin said:
John

If it's not for economy and it's not to keep the locker inactive on the street,

I guess I have been doing some assuming about what you know, and why you are doing stuff. sorry about that. Rick/Landtoy is right that we do not have a lot of experience with auto-lockers here.


It is to keep the detroit "free" during the street driving. They seem to bite a bit quicker in a toy config rather than the rover and jeep config.
 
What may be escaping most folks attention is that under normal conditons a Detroit Locker is always locked. It is designed to unlock when cornering.

On the street, in the front, a Detroit Locker would be quite the problem, hence the need for selectable hubs.

Off the road, on slippery, low traction, off camber surfaces, Detroits can also be a problem. While going straight ahead the Detroit will always be locked. This can lead to slipping down side slopes. This highlights the major advantage of an pnuematic or electric lockers - they can be turned off when not needed.
 
z80 said:
...They seem to bite a bit quicker in a toy config rather than the rover and jeep config.
I don't quite understand this. Since the Detroits are always locked unless corner, what does "bite quicker" mean?
 
Rich said:
I don't quite understand this. Since the Detroits are always locked unless corner, what does "bite quicker" mean?

it means that in the others, they seem to be more sensitive to pressure, where as in the toy, they don't seem to disengage as quick. Sorry if I said it wrong.

It does take some getting used to in driving with detroits or tru-tracs. you learn to be much more into finesse than the stupid pedal.

the good thing is that you never have to worry whether or not you should engage. Saves a lot of "well, lets try this again"

j
 
John,

The 93-97 80s don't use a true "viscous coupling". They use a fluid coupling piggybacked onto a gear driven traditional center differential that allows for a bit of rotational speed difference between the front and rear shafts. The difference is the VCs are constantly varying the torque split and essentially the VC simply replaces a differential. The 80s fluid coupling is designed to facilitate good road manners for a full time 4WD system.

Also, someone asked what year is your 80? I'll repeat that.

And I think the best way for you to get information from the 80 crowd would be to explain what you want your 80 to do that it cannot do now. I just read the entire thread and everyone's coming at this from different angles and chasing tails because the question is ill-defined. JMO.

DougM
 
hmm i feel i have dabbled here just a little. sorry if i complicated things.

Rich, you are right that I was thinking the detroit would auto-engage rather than disengage, but I think the potential problem is the same either way, which is that the locker can be on when you want it off.

John, I still do not understand what I am being corrected on in thread 22 above but there is no need to correct me again. I will figure it out some day.

Doug, I hesitate to dig myself any deeper in this thread, but to prevent any more confusion, I agree it is not a viscous coupling serving as a differential if that's what you mean by a "true" vc, but I do think it is a vc doing a different job and Raventai's linked article probably describes it best as a VC LSD.
 
Since the VC or more accurately the "control coupling" is in the ABS trucks only. I have to beleive it's do to the fact that our 80s aren't 4 wheel ABS but in fact 3 wheel, so to speak. The rear wheels are controlled together and not split. So if one of the rear wheels starts to lock BOTH wheels at the rear are affected, which could greatly unbalance the braking from front to rear of the truck. I beleive the "control coupling" helps to balance this out when that condition arises.

This is just me looking at the system and drawing my own conclusions. Flame away!
 
Nay said:
Let's turn that question around. Unless you are getting stuck at the mall or on these dirt roads, why do you think you need upgraded differentials and the tradeoffs that come with them?

Nay


Nay,

The why is basically that open diffs suck.

As I understand it, even though you have a front to rear torque biasing, once one wheel front or rear spins, it is all over for that end of the vehicle. The axle is "out of the game". The LSD prevents that by giving more more torque to the wheel that has more traction.

Plus, these things work automatically without flipping switches and user intervention.

I have had good luck with limited slip diffs in trucks (like my F250), and it works fine. I've never experienced the pitfalls being described.

My best experience was with a Quaiffe (torsen type) differential in my old rally car. I replaced the factory open diff with a Quaiffe torque biasing LSD and it made the otherwise traction-less VW into a very capable off road racer. Almost as good as 4wd (well, not really, but you get the idea).

I live in rural Vermont where a large portion of my driving is on dirt roads of varying conditons. Not your Rubicon or something, but secondary dirt roads. I live on a dirt road on the side of a mountain and have a long gravel driveway. And yes, places I go, I sometimes do want more traction - the 80 is OK stock (no lockers - bad purchsing choice on my part) but I cannot climb some steepish hills that I have tried on my property in the snow, I just sit and spin until I back down.

I'm not really the mall type, just ask my wife...

I am debating the ARB setup, but the money is daunting. I do not need to rock crawl, but I would like increased traction on gravel. I would like the factory locker setup, but I blew it on the purchase plus a couple of grand is a lot of money for occasional use an NO "rock crawling" on my part.

That aussie locker is under $300 and easily do-it-yourself installs in the stock non-locker housing from what I read on the sponsors website linked above.

I'd prefer a Quaife type setup, but 1) they do not offer one for the LC and 2) they are as expensive as lockers.

I have considered what BJowett posted on another thread and may look into the Supra torsen type diff for the front. Sounds like it is a cost effective option. Wish I could get one for both ends of the LC.

Charlie

PS. I think have misunderstood these aussie lockers. I mistakenly assumed they were unlocked until they are needed. From reading posts above, I can see that the opposite is true. Perhas this is not a good option. I think I need a torsen type diff to do what I am imagining.
 
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RavenTai said:
Some reading that may help

The HF2AV tranfer case (differential and VC info starts on page 65)




what year 80 do you have?

Just now got a chance to read that file. Awesome. That tells me everything I need to know. I have yet to find the factory shop manual for truck, so I am theorizing on a lot. I haven't had time to tear it all apart and put it back together yet.

Looks like I have to go selectable/lsd unless I change the tcase.

its a 94
 
Charlie,

Let me help you out with the lsd thingy. Quaiffe's are awesome. There is a reason they are so expensive. I would love to find one from a supra race car to drop in the front. However, that won't happen.

There are basically two types of LSD's on the market, (no comments about the differences in blotter and windowpane please) geared torsion, and clutch type. Most clutch type are shiat for low speed off-roading. They take forever to engage, and usually it's too late when they do. Also, they are filled with clutch packs, which wear, and are usually not servicable. The clutch packs are awesome for track racing though.

Geared or torsion style are where it's at. Trac-tech makes the best for off-road. However, they are much more positive engaging, and will create torque steer on road. Not bad, much like a typical front wheel drive car.

There is a reason that most millitaries use detroits or gov-loks, or fully manual/vaccum positive selectables. Less to go wrong, and more bullet proof. ARB's are fine, however the ancillaries can leave you stranded. I spent almost 4 hours repairing another guys air lines after a failure (rock induced) as there was NO way to get it to engage without air, and we couldn't get back without a front locker.
 
John, you can order the FSM from Cruiserdan when he gets back from Moab next week and you won't beat his price for a paper version. There is no substitute for it imho.

one other option to consider if your budget would allow is to use downey cable locker actuators with factory locker axles. Landtoy80 on this board has done it on the rear instead of repairing a broken oem activator.

https://forum.ih8mud.com/showthread.php?t=1625&highlight=cable+lockers

https://forum.ih8mud.com/showthread.php?t=11234&highlight=cable+lockers
 
yep, if I don't do a tru-trac, I will probably go that route or a jac mac
 
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z80,

Thanks. I poked around on the detroit locker site.

I see what I want, but they don't make it for 80's yet - the Detroit Electrac.

It is a gear driven LSD, but is also an electric locker. Best of both worlds if you ask me...

Called them and it is only available for the Dana 44 and Dana 60 for now.

Charlie
 
CharlieS said:
z80,

Thanks. I poked around on the detroit locker site.

I see what I want, but they don't make it for 80's yet - the Detroit Electrac.

It is a gear driven LSD, but is also an electric locker. Best of both worlds if you ask me...

Called them and it is only available for the Dana 44 and Dana 60 for now.

Charlie


I've been watching that for a few years now. It doenst look like they've expanded the applications since they started selling the Electrac. :crybaby: :frown:
 
Jomama said:
I've been watching that for a few years now. It doenst look like they've expanded the applications since they started selling the Electrac. :crybaby: :frown:

nope. It's called demand. If everyone buys arb, then no one buys trac tech.

Rover is the same way. There is only so much demand, and everyone becomes sheople in that if "so and so runs arb" then I should run it too.

The best part about an electrac is that if you lose power, it's still at least a lsd.
 
It is a damned shame...

It looks like a hell of a product.

Charlie
 

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