30 spartan locker engaging with driveshaft in and 2wd.

So this one should make everyone think.

Have a D30 with 4.56s a stock drive shaft and a nvg241or.
In 4wheel everything works as it should.
But in 2wheel turning 90* and a little less the front wants to engage and really bucks the front end. If i pull the front shaft all this stops and the locker acts like it should in 2wheel. No feeling and sometimes hearing it click. The drive shaft joints are nice and free and so is the center ball. The tcase is really in 2wheel and i have no rotation when up on stands. The pinion drag is fine and well within spec. The carrier speced out great with the locker installed and i have checked it twice after the frist install.

Its almost like the spring in the locker are to stiff and the drag from the driveshaft is locking it.

The spartan locker is always pretty much locked. It will turn both axles unless you have a center axle disconnect. The spartan will always turn the driveshaft even in 2wd. Even if you have a center axle disconnect. Question is did you just recently install this spartan or has it been in there for a while and this new noise. If you have recently install this locker this is pretty much characteristic. I had an Aussie locker in my 87 with no axle disconnect. Driving in 2 or 4 wheel drive it was fine. Low speed parking lot driving and turning the locker would pop and bang at low speeds.


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I know it will turn the drive shaft regardless of Tcase selection. Only thing going to stop the driveshaft from turning is a open cad axle or locking hubs. All things just seem to point to the added rotating mass of the driveshaft being connected. But i know %100 its not getting any torque input from the tcase.

Its been installed for a few thousand miles now and i have just had the driveshaft in and out for some of that so it wouldn't buck and i could drive it. Its really done this from day one and without another person with a auto in the front to compare to i was not %100 if it was odd or not. The Aussie in the rear is like all other autos i have had in the back and sounds and works fine.

This is the first Spartan i have dealt with and being for the most part just like most other lunch box lockers i wouldn't expect it to act much differently. Only reason i went with this locker VS another Aussie was i needed it now and it was in stock. And the added better cross pin was a nice touch.

something is wrong. the locker should be completely invisible while in 2wd. the front drive shaft will spin regardless. if I had to guess, id say installation error when installing the unit, most likely have the position of the springs and pins backwards

The spring in the locker you mention is NOT to disengage it...it is actually to ensure at least 1 side is always engaged. It is designed to keep the inner plates a certain distance apart which prevents the possibility of both plates being against each other @ the center pin and the outside plate teeth not being engaged on at least 1 side. If that happened, you wouldn't be able to move, so they put the springs in to make sure it doesn't.

The ONLY way a lunch box locker will disengage is if the wheel on one side is rotating FASTER than the driveshaft is driving the center pin so there is enough torque/force to overcome those springs & allow the locker to disengage. It doesn't matter if it is a front or rear axle.

Drag from the driveshaft should UNLOCK the axle, not lock it, since the center pin would be trying to spin slower than the tire.

IN a front axle, in 2wd, the locker should unlock and lock at will.

bluejeepkid said:

something is wrong. the locker should be completely invisible while in 2wd. the front drive shaft will spin regardless. if I had to guess, id say installation error when installing the unit, most likely have the position of the springs and pins backwards

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how do you get the "position of the springs and pins backwards"? In a Spartan this is basically impossible.

A spartan is made of a much higher quality material with a more aggressive cut to the teeth. Those two things create a insert that doesnt like to break free as easily as a Aussie say, that the teeth can jump free easier and they round off easier so are even less aggressive in time.

What you're experiencing, I find about 10% of the time, when dealing with a Spartan

TRCM said:

Drag from the driveshaft should UNLOCK the axle, not lock it, since the center pin would be trying to spin slower than the tire.

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Incorrect.
Drag/force (Either direction) ramps up the center shaft on to the cam gear, forcing that gear "outward" and upon doing so makes the engagement that much "tighter" so it doesn't want to disengage as freely..

RWKHausSupply said:

Incorrect.
Drag/force (Either direction) ramps up the center shaft on to the cam gear, forcing that gear "outward" and upon doing so makes the engagement that much "tighter" so it doesn't want to disengage as freely..

Click to expand...

If the difference in rpm between the ring gear and the axle shaft is big...I agree.

I assumed since the word 'drag' was used, that the difference was small, like when the rear axle disengages due to the outside tire spinning faster during a turn. Just enough difference to let the cam plate as you call it move inward and disengage the teeth until the speeds are equal again.

If the difference is large, then if the wheel is spinning in a forward direction, then the difference in rpm would cause the cam plate to lock up on the backside of the center pin instead of on the front side like normal.

But yes, it would lock up as you said.

I have an aussie in my dana 30 and that thing will ratchet and clank during u turns but it hasn't caught and jerked the front end.

After having lunchbox lockers front and rear with a manual trans, where you can really feel the driveline loading and unloading, tire pressures make a difference. I would experiment with that and maybe use different gear oil?

I know the springs encourage it to stay locked until you over come them with a turn. But seems to me if maybe some how i got stiffer springs it would be harder to over come and adding the drive shaft (rotating mass) put its over the edge and makes it really want to stay locked. I dont see how you could ever install the thing wrong even more so whel you follow the instructions. And this os by far not my first rodeo. So unless somethings out of spec that i can only see with a mic then i dont know. If the weather holds up i will mount the gopro under to show how bad this are. I really feel im going to break something or really speed up the ware of something.

TRCM said:

If the difference is large, then if the wheel is spinning in a forward direction, then the difference in rpm would cause the cam plate to lock up on the backside of the center pin instead of on the front side like normal.

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So in reverse the locker doesnt function?

The cam gear is the same on either side of the cross shaft opening, and doesn't care of its on the forward rotation or the reverse rotation. IF it (cross shaft, which is 100% in mechanical lock with the carrier, which is in 100% lock with the ring gear, and then the pinion, then the driveshaft, etc) sees force (in either direction) is ramps up the cross shaft opening and engages the locker side halfs proportionately more aggressive.......

RWKHausSupply said:

So in reverse the locker doesnt function?

The cam gear is the same on either side of the cross shaft opening, and doesn't care of its on the forward rotation or the reverse rotation. IF it (cross shaft, which is 100% in mechanical lock with the carrier, which is in 100% lock with the ring gear, and then the pinion, then the driveshaft, etc) sees force (in either direction) is ramps up the cross shaft opening and engages the locker side halfs proportionately more aggressive.......

Click to expand...

I think you are reading something into this i didn't say (or mean).

And I can attest it locks in both forward and rearward directions...at least my spartan & lockrights do/did.

Let me use leading & trailing instead of forward and backwards or front/rear.

I said if the tire was spinning in a direction to move the vehicle forward, the drag would cause the cam to lock on the 'trailing side' of the center pin relative to the direction it is spinning...which is exactly opposite from the normal way it would lock when moving forward.

The same is true of the vehicle is moving backwards.....if the tire is spinning in a direction to move the vehicle backwards, the cam would again lock on the 'trailing side' of the pin due to the drag, which again, is 100 % opposite from the normal way it would lock.



Normal locking comes from the center pin being driven by the driveshaft, and when that is the case, the pin will always lock on the leading side relative to the direction of rotation. If the driveshaft is not the source of power, the pin will always lock on the trailing side.

Either way, front of the pin or back, it will lock if the cam plate is forced against the center pin.



Normal operation, the ring gear is 'spun' by the driveshaft, and this causes the center pin to move in a forward direction (relative to the direction it is spinning) which lets the center pin contact the cam plates on the leading side of the pin and force them outward and away (they will still be in contact with the center pin tho). This forces the cam plates out, locking the diff up.

Now, in the scenario above, the ground is what is driving the front wheels (2wd remember), not the driveshaft, so the center pin is not being 'pushed' by the driveshaft/ring gear, it is being 'pulled' by the axle shaft and the fact that the at rest state of the locker is locked (those little springs). The difference, is the cam plates are not in contact on the leading side of the pin relative to the direction of rotation, but instead on the trailing side, since the force driving all this is coming from the tire/friction against the ground...not the driveshaft.



.

How's the angle on the driveshaft?


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TRCM said:

I think you are reading something into this i didn't say (or mean).

And I can attest it locks in both forward and rearward directions...at least my spartan & lockrights do/did.

Let me use leading & trailing instead of forward and backwards or front/rear.

I said if the tire was spinning in a direction to move the vehicle forward, the drag would cause the cam to lock on the 'trailing side' of the center pin relative to the direction it is spinning...which is exactly opposite from the normal way it would lock when moving forward.

The same is true of the vehicle is moving backwards.....if the tire is spinning in a direction to move the vehicle backwards, the cam would again lock on the 'trailing side' of the pin due to the drag, which again, is 100 % opposite from the normal way it would lock.



Normal locking comes from the center pin being driven by the driveshaft, and when that is the case, the pin will always lock on the leading side relative to the direction of rotation. If the driveshaft is not the source of power, the pin will always lock on the trailing side.

Either way, front of the pin or back, it will lock if the cam plate is forced against the center pin.



Normal operation, the ring gear is 'spun' by the driveshaft, and this causes the center pin to move in a forward direction (relative to the direction it is spinning) which lets the center pin contact the cam plates on the leading side of the pin and force them outward and away (they will still be in contact with the center pin tho). This forces the cam plates out, locking the diff up.

Now, in the scenario above, the ground is what is driving the front wheels (2wd remember), not the driveshaft, so the center pin is not being 'pushed' by the driveshaft/ring gear, it is being 'pulled' by the axle shaft and the fact that the at rest state of the locker is locked (those little springs). The difference, is the cam plates are not in contact on the leading side of the pin relative to the direction of rotation, but instead on the trailing side, since the force driving all this is coming from the tire/friction against the ground...not the driveshaft.



.

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All that to say the same thing, which is not making any sense....

Plain and simple. Force either direction on the driveshaft will cause the cross shaft to apply force on the cam gears, in turn applying force outward on the cam gears. PERIOD... No need to try and make up terms such as trailing or leading or turning or blaw...

If there is FORCE being applied relative to the ring gear/carrier, then the cam gear(s) are having force applied to the side gears.....

themauler said:

How's the angle on the driveshaft?


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Click to expand...

This could effect it

RWKHausSupply said:

All that to say the same thing, which is not making any sense....

Plain and simple. Force either direction on the driveshaft will cause the cross shaft to apply force on the cam gears, in turn applying force outward on the cam gears. PERIOD... No need to try and make up terms such as trailing or leading or turning or blaw...

If there is FORCE being applied relative to the ring gear/carrier, then the cam gear(s) are having force applied to the side gears.....

Click to expand...

You still don't/aren't getting it........I am not talking about the driveshaft changing direction of rotation...I am talking about the center pin changing WHERE it contacts the cam plates, not how.

I never said the locker didn't lock in both directions...you somehow just got that in your head. I in fact, said mine DID lock in both directions.


OK, I do and always did agree with you that the locker will lock no matter what direction the driveshaft OR center pin rotates/moves/spins or whatever you want to call the motion, as long as the center pin can MAKE contact with the cam plate.

What I was talking about was the difference in a driving force and a dragging force, and how they affect HOW the center pin hits the cam plates.

If the driveshaft is what is driving the center pin (driving force), the pin will move causing the pin to hit the cam plate, and it will hit the cam plates and force them out, and lock the diff up....and will continue to do so until either you let off the gas or you make a turn.

If the driveshaft is NOT driving the center pin, as is the case when the front driveshaft is free spinning (which is what the OP is talking about), then the axle will rotate the coupler & cam plate, which will then cause the cam plate to hit the center pin, which causes the cam plate to be forced outwards, again locking the diff up. The difference here is, since it is a drag or dragging force that is causing the center pin to move, that force can change easily, and let the locker unlock or lock as it sees fits.

The statements in italics are opposites because the driving force is opposite....in the 1st case, it's the driveshaft spinning the ring gear & center pin, in the 2nd case, it's the tire moving along the ground, rotating the axleshaft, which then rotates the cam plate until it hits the center pin and locks up.



Think of it this way maybe........if you want to torque the lugnuts on your vehicle, you put the lug wrench on the lug nut and turn the wrench clockwise while the tire stays still right ??? (driving force)

But you can also hold the wrench still while someone rotates the tire counter-clockwise....(drag force)

Both ways, the lug nut gets tightened, but how the force is applied to tighten it comes from opposite directions.



If you really think what I said doesn't make sense, IM me and we can talk on the phone. Maybe I just suck at explaining it to you.

If I was standing in front of you with a locker & diff, I could show you, and you would immediately see what I am saying.......

Maybe this will help ??

In the below pic, the center pin is touching the cam plate @ the 12:30 & 6:30 positions because the pin is rotating clockwise, and when it hits the cam plate, it forces it out to lock up the diff. The driveshaft is spinning the diff which forces the pin to move to force the cam plate to move. (leading edge)

Now, if the cam plate was to move in a clockwise direction, it would hit the center pin @ the 11:30 & 5:30 positions because the cam plate is spinning, which would force the center pin to hit the cam plates, forcing them out and locking the diff up. (trailing edge)

The whole assembly is still rotating clockwise, but the pin to cam plate contact points are not the same since the driving force is coming from a different place.

themauler said:

How's the angle on the driveshaft?


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Click to expand...

It was something i did think about. I even went for a drive with 0 caster (pinion closer to inline with the driveshaft) and it didnt change that problem. Controlling the Jeep was a hand full but thats going to happen. The angles are not bad. And it didnt get worse after i clocked the Tcase up more.

So i looked again at the gap and im at the lower end of the range. .145-.170 and im at the .147 maybe .148. But its within spec so wtf.
And i know for a fact i did not use the thrust washers. I have them in a bag with my spiders.

My aussie locker was doing doing the same thing. New axle shaft ujoints all but eliminated the issue. Clicks like it should now but no longer binds on sharp turns.