When will your Jeep GO/NOT GO? Discussion on driving LOCKED.

AdamIsAdam · **Posted:** Fri Jul 14, 2006 11:54 am

I'm about to install a rear locker (Powertrax no-slip)(please see this threadfor a discussion about which locker to buy), and was looking for feedback on how to drive witih it. And also exactly how it will work.

Let me start off by saying I've got a pretty good handle on how this all works and probably wheel more than most on this board. But yet, I'm still only 3 years into this thing and am always eager to learn from those who know more than I!

Assume we're talking about being in 4LO, so the transfer case is locked.

If I've got diagonal wheels off the ground (ie, FR and LF) and I'm not locked at all, I stop dead. I cannot crawl forward because one rear and one front wheel can freely spin.

If I've got one wheel off the ground, any wheel, and I'm not locked, I SHOULD be able to go but only at the mercy of the traction of ONE of the other axle's wheels. Meaning, if I have a front tire off the ground, and one of the rears is on loose sand, it will likely spin instead of moving the Jeep forward. Right?

Now, add a rear locker to either scenario above. ANY TRUE locker, which means that no single rear tire can spin without both spinning. Now under scenario 1 or 2, I should be able to keep crawling, right?

The key difference being, again remember I've got one wheel off the ground and am dealing with the remaining 3, with 3 tires on the ground and open diffs, I'm at the mercy of the WEAKEST traction. With a locker, I'm at least relying on the traction BOTH rear tires. RIGHT?

And finally, the reason for the front locker, I guess, is so that the front that's ON the ground can help too, even if the rears have poor traction.

PLEASE, FEEL FREE TO RAMBLE ON here. Join me!

Oh, one last question. How can I best engage my new powertrax locker? just with the throttle? Does the parking brake play any roll here like it can on a trac-loc?

THANKS FOR READING AND POSTING! who knows, maybe you too will learn a few things from this one!

Neal · **Posted:** Fri Jul 14, 2006 12:20 pm

I've been in situation where pwr trax has unlocked. When down hill at sideways angle and trying to come out rear dropped into loose hole. One rear was on solid ground and front was a little loose. The rear wheel in hole just spun and the rear wheel that should have had traction did not turn. Tried forward and reverse -with and w/o brake and no good. Had to dig and pile rocks for wheel in rear hole and then both rear wheels locked in. This was in 4 lo the whole time of course.

Jeepjeepster · **Posted:** Fri Jul 14, 2006 2:23 pm

My powertrax locks up any time it feels like it on the road. Offroad Ive never had it unlock when I needed it. Its locked and stays lock in any low traction situation. Even when coming up my driveway and its wet, it will lock just b/c its wet and it can lock. Its a crazy little thing and does a really good job. Just take it easy on the gas until you are either straight or now all the slack is out of the drivetrain before you floor it or anything. That can be really hard on ujoints and gears when you get on it with slack in it.

Ohh, and your right about all your little theories.

Jeepin Al · **Posted:** Fri Jul 14, 2006 3:38 pm

The power trax is an interesting animal. It is locked all the time, except when you turn a sharp corner, than it unlocks and you can hear the lock cog (no techincal word mind fart) skipping while in the turn, not as bad a detroit locker, which are real noisey. The problem on the trail is when turning a tight corner the thing will unlock, and if you happen to meet mud while straighting out, no locker for a while. Once the two rear tires get to the same spedd and dirction it will lock bak up. If you lift one of the back wheels while locked in you will still have one wheel that will drive. The wheel in the air will spin at the same speed as the one on the ground (basically).

On the ice, snow and sometime rain one needs to stay off the gas while having a mechincal locker. No smashing the pedal. the rear will spin out from under you. The Jeep will most likely slide in the downward direction of the crown of the road.

I like it, however, I think if the e-locker comes out for the 8.25, I will go with it. It will be limited slip when not turned on, and a full locker when on, meaning no unlocking when turning on the trail!

Al

PS sorry for the spelling or ramblings, I have been typing since 6:30 this morning writng proposals.

AdamIsAdam · **Posted:** Fri Jul 14, 2006 3:56 pm

great info! THAnks gang.

I'm a bit worried about that unlocking while turning while offroading thing, but it sounds like I can work through it. Plus, it sounds like a basic limitation of a manual locker.

Thanks again!

krazz1e · **Posted:** Fri Jul 14, 2006 5:44 pm

in the year I had my locker and many trips of wheeling on rock, sand, loose dirt, loose rock, it never unlock on me off road.

Even on-road with high tracation it would not unlock very often, you would have to be a really tight turn with very high traction.

Despite the load clanks, which are normal and totaly fine, this locker is great, especially if you offroad.

As for the Detriot it's more rachety, I find it to be much quiter than the powertrax clanks an bangs.

DarbyWalters · **Posted:** Fri Jul 14, 2006 8:16 pm

Jeepin Al wrote:

The power trax is an interesting animal. It is locked all the time, except when you turn a sharp corner, than it unlocks and you can hear the lock cog (no techincal word mind fart) skipping while in the turn, not as bad a detroit locker, which are real noisey. The problem on the trail is when turning a tight corner the thing will unlock, and if you happen to meet mud while straighting out, no locker for a while. Once the two rear tires get to the same spedd and dirction it will lock bak up. If you lift one of the back wheels while locked in you will still have one wheel that will drive. The wheel in the air will spin at the same speed as the one on the ground (basically).

The powertrax can not tell if you are turning or going straight...it only locks when "power" is applied and unlocks when no "power" is applied. It will lock up while you turn on the street if you apply "power". Your two rear tires are "always" headed in the same direction so going thru mud makes no difference at all. They will remain locked with "power" applied unless your PowerTrax is malfunctioning. You might have a split second between the unlocked and locked stage that will leave you open for a bit but that is dictated by the application of throttle.

The thing about the "lunchbox" locker is that it will unlock easier than a "full locker" when you let off the "power" and will let the two wheels turn at different speeds when not under power. The PowerTrax will wear the carrier faster than an open with the extra stress since it is a "lunchbox" style locker (uses the same carrier and does not strengthen the rear end)

Another point from the other thread about the Detroit TT. Although it is just a Limited Slip Differential, it comes with a preload set. The worm gears engage and turn the opposite wheel even if one is off the ground...it won't be as positive as a full locker but even without brake modulation my front DTT kept both front wheels turning most of the time. The one advantage to the DTT is that when I came down hard on a wheel that had been airborne, the DTT was easier on the front end since it isn't as positive as a locker.

AdamIsAdam · **Posted:** Fri Jul 14, 2006 9:22 pm

GREAT INFO! thanks.

I have one question: what exactly is "wearing" on the stock carrier? Is the carrier the metal bucket thing that houses the spider gears, or in this case the locker? If so, I understand that it's stressing it more, but what is wearing?

Neal · **Posted:** Fri Jul 14, 2006 9:38 pm

Al is correct, Darby is incorrect, the pwrtrak can "tell" if you are turning. Look at page 6 of the user manual and it is explained quite well there. The only way to overcome this "feature" would be to POWER thru a sitiation and that would not always be prudent. In a turn the inside wheel escentially reverses relative to the outside wheel and in some conditions the pwrtrax will not relock until the stuck wheel either is given traction or the other is turn backwards.
But it is a good unit and works very well --just have to work around some of the "features"
Has help me thru stuff a lot of people could not get thru.

DarbyWalters · **Posted:** Fri Jul 14, 2006 9:43 pm

As with anything mechanical...movement and friction cause wear. The carrier is the center housing (internal) that the ring, pinion and axles meet. It is the structure that creates the strength of the rear diff. With a full locker or ARB the stock carrier is replaced with a much stronger carrier to compensate for the extra stress on the carrier. With a PowerTrax you will order your unit depending on if you have a lsd or open carrier. This carrier will be reused with the PowerTrax. Mine took a lot of abuse and did pretty well but the carrier finally failed and spun the internal into spaghetti. Just went and got a whole new rear axle and swapped.

My preference after having a PowerTrax, which took me everywhere I wanted to go, would be to go with a selectable locker ( read ARB ). Save up the money and never look back. Otherwise I would go with Detroit TT front and rear. I think this setup is probably easiest on the driveline of a KJ.

The other big concern with the PowerTrax or any type of non-selectable locker is in wet or slick conditions. YOU will probably get used to the weird attributes but if anyone other than yourself drives your KJ, it might catch them offguard. They could swap ends before they realize what is happening. If you get the PowerTrax and have Selec-Trac, it will help in this situation. Just put it in Full-Time and it controls this problem pretty well on wet or slick streets.

AdamIsAdam · **Posted:** Sat Jul 15, 2006 6:59 am

DarbyWalters wrote:

The other big concern with the PowerTrax or any type of non-selectable locker is in wet or slick conditions. YOU will probably get used to the weird attributes but if anyone other than yourself drives your KJ, it might catch them offguard. They could swap ends before they realize what is happening. If you get the PowerTrax and have Selec-Trac, it will help in this situation. Just put it in Full-Time and it controls this problem pretty well on wet or slick streets.

I do have Selec Trac, and was counting on exactly that strategy for both myself and the very occassional time my wife drives the KJ in the snow. Glad to hear my theory about that affirmed.

Due to the cost (total cost, including installation of Powertrax myself versus ARB where I'd have to pay to have installed) and because I wheel about 3-6 times per year, I went with Powertrax. $421 delievered and my own installation is considerably less that the ARB setup. If I ever have a problem, I guess I will have learned the heard way, but many hear have had the powertrax, and I think Darby is the first one I've read about that has exploded it.

Eddo · **Joined:** Thu Jul 07, 2005 7:01 pm **Posts:** 1214

Neal wrote:

Al is correct, Darby is incorrect, the pwrtrak can "tell" if you are turning. Look at page 6 of the user manual and it is explained quite well there. The only way to overcome this "feature" would be to POWER thru a sitiation and that would not always be prudent. In a turn the inside wheel escentially reverses relative to the outside wheel and in some conditions the pwrtrax will not relock until the stuck wheel either is given traction or the other is turn backwards.
But it is a good unit and works very well --just have to work around some of the "features"
Has help me thru stuff a lot of people could not get thru.

Neal is correct Adam. Look at the manual. It gives a very good explanation of how the unit works. I have one and really couldn't be happier. Never has let me down offroad. On road is a little different, but not drastic. My fiance drives the Jeep everyday and she hardly notices it.

I was really expecting something quite horrible when I first installed mine from all the horror stories. I was pleasantly surprised on how mild it was on the road. If I had to do it over again I would still go with the Powetrax No-Slip.

Just FYI. Powertrax makes two lockers that are often confused. The Power-trax Lockrite and the Power-trax No-Slip. The No-slip use syncros to maintain better on-road manners. The lock-rite does not utilize any syncros and therefore has very crude on-road manners. I had a Lock-rite style locker on my CJ and it was a beast to handle on the road.

AdamIsAdam · **Posted:** Sat Jul 15, 2006 9:33 am

Thanks for the comfort level booster. Yes, I bought the no-slip. I hear it's much better for a daily driver.

Jeepjeepster · **Posted:** Sat Jul 15, 2006 10:29 am

Do you believe the powertrax causes more wear and tear eddo? Almost everyone that offroads on here has one and Ive never heard of anyone having problems. If I do start to see failures then that thing is coming out of there and Im throwing it over the hill.

DarbyWalters · **Posted:** Sat Jul 15, 2006 1:11 pm

Neal wrote:

Al is correct, Darby is incorrect, the pwrtrak can "tell" if you are turning. Look at page 6 of the user manual and it is explained quite well there. The only way to overcome this "feature" would be to POWER thru a sitiation and that would not always be prudent.

Yep page 6 tells you that it can "tell" when you are turning and that the coupler from one side compensates for different wheel rotation. If you read that page, it tries to sell you the fact that it constantly "adjusts" for wheel speed and the synchro makes everything smooth. It also says the outside wheel travels freely while the inside wheel turns. Well I can state from experience that the transition is not like butter and I never felt one wheel disengage or run freely with any amount of power applied. You can tell that this is true once you drive one onroad or offroad. Offroad the PowerTrax No-Slip will cause you rear end to move around while climbing and turning because both wheels are turning ( whether you are turning on not---that is why you want a locker in the first place ). You will also notice at a very slow speed that you will encounter some push ( which means your rear wheels are puching your KJ forward harder that your front wheels can turn). If it worked as smooth an easily as PowerTrax says, it basically works like an open diff until you are going straight with power applied.The last line on page 6 states "Operation is precise,smooth and quiet". Do you believe that also Neil?

What it does do and this is the feature you use offroad and the reason you install a PowerTrax...When a wheel looses traction, the PowerTrax engages both sets of drivers and couplers to add power to both axles. The is to eliminate wheel spin and enhance traction. Guess what, if the PowerTrax read this as a turn it would not transfer power to both axles. The point is when you apply power the PowerTrax sends input to both wheels/axles.

The proof is when driving on a wet road...if the PowerTrax was so precise and quiet, you would not get the fishtail that is prominent when turning on a wet street with even a minimal amount of power. You do get that charactersistic because the PowerTrax does not precisely or smoothly disengage the outside wheel of a turn with any power applied.

Now, it is as drastic as a Full Detroit Locker or Welded Spider because there is some "slack" time and differentiation but it is not invisible by any means. Basically an open diff leaves one wheel spinning without traction spinning while the opposite wheel does nothing. A LSD transfers "some" of the power to the wheel that is not slipping from the the wheel that has no traction...depends on you LSD how much is tranferred. The No-Slip transfers "more power" to the wheel with traction and less (yes it differentiates) to the wheel with no traction. But from experience and from the on and off road characteristics it does not completely eliminate power to the spinning wheel...it applies power to both with more force than a LSD. It does cause the rear end to move around and it will cause a push on tight trails in the right conditions. If you think about it, it "locks" up and stops wheel spin for a reason and that is why they work. The Powertrax "IS NOT" deciding if you are turning or not...it is just adjusting to wheel speed whether going straight, backwards, turning, in mud, climbing ect. It does differentiate wheel speeds somewhat but you will be able tell it is a locker and has those attributes.

Go to the bottom of page 10 and on to page 11...those are the attributes I am talking about..."Should you wish to minimize the effects of torque transfer, take turns under "LESS THROTTLE", and make "THROTTLE CHANGES" more gradually to allow for the smoothest possible operation. When you power through a turn, you may feel a degree of "under-steer", the tendency to straighten the vehicle's path of travel due to torque transfer to the inner wheel. Sudden throttle changes during turns will accentuate "under-steer", especially on slippery or unstable surfaces."
The first part of the description is to Sell the Unit...the last part is to Warn you of the Characteristics...

When all is said and done...the PowerTrax has probably the best "bang" (pun intended) for the money. I am not trying to start a he said she said thread. I am just relaying my experience with the PowerTrax and to say that although is does "operate" in the manner that PowerTrax puts forth...it does not do that without drawbacks or as "smoothly" as they try to sell.

jason thompson · **Posted:** Sat Jul 15, 2006 2:48 pm

i just recently rode in a TJ with a tru-trac front and a detroit ,that replaced a power trax, rear the owner said that the new datroit locker was alot quieter than the power trax and alot less "surprise" to it i think he was talking about it locking and unlocking not sure

the reason he replaced the powertrax was that it exploded in gilmer on a hill that just 8 months ago i climbed with an open diff he is only running 33's so i dont think that tire size was a problem

i have an ARB front and would never have any thing less (TJ)
i am saving a few bucks to get the rear (dana 44)

my view on lockers ,or any thing for my jeep for that matter, is you get what you pay for
if you only pay $400-$450 for a locker then you will get that much locker it will work but not as good as a $600 detroit
just like the new electric lockers that will be cheeper than the ARB,s will they work as good or be as reliable or will they be like comparing the detroit to the powertrax? i do not know i know they all work but some better than others

its kind of like comparing snap-on to craftsman sure it will work ok most of the time but when you need it for that realy big job will it fail?
do you take that chance? if it breaks will you be stranded? things to think about
besides just cause every body else is doing it does that make it right? all you friends jump off a bridge situation if i jump i want a parachute

AdamIsAdam · **Posted:** Sat Jul 15, 2006 8:33 pm

jason thompson wrote:

(a lot of stuff)

And just because everyone else uses punctuation, why should you?

Sorry, had to do that.

I think this is great info. I wanted to hear REAL experiences, from really EXPERIENCED folks on this topic. Mission accomplished.

I think this is very helpfull banter. Thanks!

Based on everything I've read, I'm really looking forward to installing my powertrax. Mr. FedEx says I'll have it monday!

Neal · **Posted:** Sat Jul 15, 2006 8:55 pm

Adam
steve has a write-up in the tech section--you will have to grind down one of the c-clips slightly

AdamIsAdam · **Posted:** Sat Jul 15, 2006 9:22 pm

No grinding on the powertrax no-slip. I believe grinding was for the trutrack or one of the other models.

Or was that the one that he thought the c-clip was getting hung up? I'll have to go back and re-read it. But your'e not SUPPOSED to have to grind anything for the powertrax no slip.

Neal · **Posted:** Sat Jul 15, 2006 9:32 pm

You probably will have to grind the one c-clip, try it on the bench first. Also fit the parts on the bench first and I marked mine with a sharpie pen so the orientation was correct. It's easier before your all greasy.

When will your Jeep GO/NOT GO? Discussion on driving LOCKED.

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