Differential Questions.....Locking or not

[Clint Dixon]

I did see the tree saver, but you guys are luckier than we, we can no longer travel in road less areas.
Down here they are looking for any excuse to close areas to off road travel.
Forget about "rubbing". There are areas here where we can't even pick up "down and dead" for camp fires....= (

If a tree hugger fell in the woods, and no one was around to hear, would anyone care? ;^)

[MasterYota]

If a tree hugger fell in the woods, and no one was around to hear, would anyone care? ;^)

Nope - not me anyway.

I live about 500 miles further north than Chris does, and we have approx. 1 conservation officer for every 100 000 square miles. The chances of us running into one is pretty slim. That dosen't mean however that we have a cavalier attitude towards the land. We just take things with a grain of salt. ie. once a road, always a road....
Our provincial government killed more timber with thier ignorance and inactivity in dealing with our pine beatle infestation that all the wheelers of the world could ever damage in a lifetime. And with the forest industry being heavily tied to the economy, environmentalism has taken somewhat of a back seat in the legislature lately. That inturn means great access for us all - for now...

[MoparNorm]

You guys are lucky, our democrats down here have no ability to conceptualize the cause and effect of enviro laws upon the economy, all we get is tax and close, tax and close....= (

If the Boston Tea Party was held tomorrow, they'd all be rounded up and thrown in prison for polluting the Harbor...

[MasterYota]

You guys are lucky, our democrats down here have no ability to conceptualize the cause and effect of enviro laws upon the economy, all we get is tax and close, tax and close....= (

If the Boston Tea Party was held tomorrow, they'd all be rounded up and thrown in prison for polluting the Harbor...

Our biggest problem with the governement up here is that they can't see the big picture. Our provincial capital is on Vancouver Island. They see a little problem there, and figure it must apply to the whole province. When in reality, its just a tiny little isolated problem.

Most people up here tend to take for granted the access that we have to the outdoors. And thats a shame, because the political powers would take it away if they could. The problem is enforcement. They don't have the manpower or financial resources to strictly enforce most land closure issues. They tend to pick an area that is of in contention by Special Interest groups and Greenies and focus it. I will say though that our Ministry of Forests and lands is usually quite receptive towards back country users if approached with a good attitude. Our club has taken several MOF members out on runs and they have all had a great time, and they are now aware of what we do, and how we do it. They are now an asset to us instead of a hinderance. Join an organization, it will help keep land open in the long term, and serve to educate those who are ignorant towards the backcountry.

Rant over... sorry for the thread hijack

[Doakster]

Back to the topic at hand, there are only two available traction aiding devices for the M37/PW diffs. The always available lockright, or the once-in-a-while limited supply of ARBs. I guess in the end it comes down to how badly an Truck owner wants the additional traction. If ARBs are not available, then I guess you could purchase a lockright, and drive the vehicle, or let it sit in the garage until an ARB becomes available.

There is also one other avenue that we've not touched on that can cause axle shaft failure, and play a huge role in traction, and thats tires. Larger than stock tires can break axles due to the increase in mass that needs to be stopped and started. A good set of tires can make alot of difference, and could influence the decision to purchase a locking diff or not. The NDT's are pathetic in terms of performance and traction. But if a stock looking appearance is what is wanted, then a locking diff might make all the difference. If looks are out the window, then a newer set of tires, in whatever tread design, might provide enough of a gain in traction that a locking diff isn't warranted. An aggressive right foot, and the gearing in these trucks will break parts though - locking diff or not.

Nice picture by the way Norm...

So to get back on topic.....how often are the ARBs available and from who?

[Charles Talbert]

So to get back on topic.....how often are the ARBs available and from who?

Go to www.powerwagonlocker.com A run is being made now I understand, the guys name is Dan Shockley. Nice fellow to deal with, taking deposits, the units are due for delivery in April I believe.

[Marius]

What scared me from the lockrites and to choose ARBs instead was the pulling of heavy loads on hard surfaces. The lockrite will transfer all tourqe through only 1 axle shaft and put a considerable strain on it, while the ARB, working as a stock differential, would evenly distribute the tourqe on both axleshafts. Correct me if I am wrong.
Marius

[Charles Talbert]

You are correct, it will keep right on going until no axle shaft is left to break. This is the main reason I do not recommend them to my customers. Example: 1 shaft breaks, operator never knows until 1 of 2 things happens, he gets into a situation where he notices he has 1 wheel not pulling or the 2nd axle breaks in which case all pulling is over. The killer is usually this; when the 1st axle breaks, because the operator doesn't know in most cases until a significant time has past, shivers of metal from the break are circulated throughout the entire differential in the oil doing much physical damage to bearings, gears, & the diff carrier housing. Oil passages becoming clogged slowing or stopping oil circulation is also a huge issue. Many times the whole unit is heavily damaged or destroyed as a result before you know a problem is at hand. A huge risk to take & an extremely high $$$ repair in the event of a worst case scenario. Just the bearing kit for 1 differential runs well over $500 these days.

A great asset offered by the ARB is the fact that it can be disengaged when not needed such as hard surface travel as you mentioned.

[MasterYota]

Sorry Marius, I must disagree.

In a straight line - all things being equal(tire size, air pressure, etc..) regardless of using an open diff, lockrite, or ARB, the strain on the axles is the same on each side. When no differentiation is required an open carrier will load both axles the same as a locked carrier. When traction changes between the two tires, an open diff will send power to the tire with the least amount of traction (road friction, bias, whatever you'd like to call it).

When cornering - an open differential will allow the outside wheel to turn faster than the inside wheel. As there is no increase in ring gear revolution, I would make the conclusion that most of the torque is traveling down the inner axle to the tire that is turning at the same speed as the driveline (the inside tire).

A lockrite allows for the same function. It allows the outer wheel to turn faster than the ring gear, to make up the addtional distance of traveling in an arc. Where an open diff is seamless upon exiting the corner, an operator might feel a small bump as the locker re-engages.

When an ARB is engaged it functions just like a spool - no differentiation. In a straight line this isn't a problem. When cornering though, both wheels must turn at the same speed as the ring gear. The outside tire in the arc cannot turn faster to make up the difference so it ends up turning and skidding as its dragged through the corner until the vehicle straightens out again. This jerking and skidding puts terrible stress on the driveline as the axle loads and unloads sporadically. This isn't a big deal when the terrain is loose, like gravel, or sand, or mud, as the tire can slide around without causing additional stress to the driveline. It is a big deal when the ARB is engaged on pavement or concrete. These high friction surfaces make driveline stress go through the roof.

I've seen more broken axles on open diff vehicles than I've ever seen with any type of locker. In low traction situations, one tire will be spinning away and then suddenly grab - this forces the power over to the other wheel which isn't moving, which inturn is expected to handle the sudden torque input and snap, its overwhelmed and broken. Lockers, whichever style are meant to load the axles evenly. Any locker is a benefit in my opinion

Broken axles make ALOT of noise and funky vibrations. I find it hard to imagine that anyone capable of fixing (or even driving!) an M37 or FFPW wouldn't notice that something was wrong locking diff or not. Field removal of a broken rear axle is as easy as it gets with these trucks. People who continue to drive on broken axles, and then further damage other parts will get no sympathy from me. It takes 10 minutes to remove a broken axle - there is no excuse for for excessive driveline damage due to lazyness.

[Marius]

MasterYota wrote:
"In a straight line - all things being equal(tire size, air pressure, etc..) regardless of using an open diff, lockrite, or ARB, the strain on the axles is the same on each side. When no differentiation is required an open carrier will load both axles the same as a locked carrier."

-Yes, but on a lockrite equipped vehicle, this condition is rarely met. To make the lockrite as smooth-working as possible, the overlap phase (when both axleshafts are engaged at the same time) is made as small as possible. On a perfect flat smooth road, going perfectly straight ahead, equal tire pressure, load and etc, yes, the lockrite will transfer equal torque on both axleshafts. As soon as you get in your truck and actually try to drive somewhere, the lockrite will continuously shift between transfering 100% of the tourqe to either the left or the right shaft.

Now, lets go to wikipedia and see the definition of a differential:

In an automobile and other wheeled vehicles, the differential allows each of the driving wheels to rotate at different speeds, while supplying equal torque to each of them. In automotive applications, the differential and its housing are sometimes collectively called a "pumpkin" (because the housing resembles a pumpkin).

Wow! Equal tourqe to each wheel. Assuming the wikipedia article is correct, the lockrite will in nearly all cases, double the strain on either axleshaft compared to ARB or stock differential.
Luckily, axle shafts are engineered to handle alot more than normal use. But when using a lockrite, you have already spent most of that built-in extra. And if you then try to do some heavy work, dont be surprised if that poor axleshaft cant take no more.

Now, this is how it works as long as the driver cannot influence much. But if you go offroad, and get that wheel off the ground and spinning real hard. Then fall down on it with the weight of the vehicle, yes, the axle shaft is likely to break. In these cases a lockrite will keep the driver from doing stupid things like that. As an ARB would do (if engaged).

Anyway, your use must decide what lockers you need. Lockrite is a cheap option for offroading but your driveline strenght on regular use is halfed. Put that in consideration if you load your truck or do any towing.

With ARBs, you get the best of both worlds.

MasterYota wrote:
"When cornering - an open differential will allow the outside wheel to turn faster than the inside wheel. As there is no increase in ring gear revolution, I would make the conclusion that most of the torque is traveling down the inner axle to the tire that is turning at the same speed as the driveline (the inside tire).

A lockrite allows for the same function. It allows the outer wheel to turn faster than the ring gear, to make up the addtional distance of traveling in an arc. Where an open diff is seamless upon exiting the corner, an operator might feel a small bump as the locker re-engages."

About the tourqe, read the wikipedia article:
http://en.wikipedia.org/wiki/Differe...28mechanics%29

A simple way to describe the lockrite is to see it as a free-wheeling device, where the fastest travelling wheel will always be free-wheeled.

MasterYota wrote:
"When an ARB is engaged it functions just like a spool - no differentiation. In a straight line this isn't a problem. When cornering though, both wheels must turn at the same speed as the ring gear. The outside tire in the arc cannot turn faster to make up the difference so it ends up turning and skidding as its dragged through the corner until the vehicle straightens out again. This jerking and skidding puts terrible stress on the driveline as the axle loads and unloads sporadically. This isn't a big deal when the terrain is loose, like gravel, or sand, or mud, as the tire can slide around without causing additional stress to the driveline. It is a big deal when the ARB is engaged on pavement or concrete. These high friction surfaces make driveline stress go through the roof."

Yes this is true. Also, driving with the emergency brake engaged will cause driveline stress, excessive heat and wear, high gas milage, etc. Something which is also very stupid to do.

MasterYota wrote:
"I've seen more broken axles on open diff vehicles than I've ever seen with any type of locker. In low traction situations, one tire will be spinning away and then suddenly grab - this forces the power over to the other wheel which isn't moving, which inturn is expected to handle the sudden torque input and snap, its overwhelmed and broken. Lockers, whichever style are meant to load the axles evenly."

This is true, though its my impression thats it is the axleshaft on the side of the spinning wheel with its built-up momentum that snaps.

MasterYota wrote:
"Any locker is a benefit in my opinion"

Wiith the lockrite, you have to give and take.

MasterYota wrote:
"Broken axles make ALOT of noise and funky vibrations."

Sometimes they do, sometimes they dont. It depends on the shear. I have had a front axle axleshaft break in a straight even shear. It did not make any noise. I noticed it because I had no traction on the front axle. On careful inspection, the only visible sign was the "freeze-plug" on the hub drive flange had moved slightly outward. If I had had a lockrite installed, I would not have known. I would have assumed that the other wheel had the least traction.

MasterYota wrote:
"I find it hard to imagine that anyone capable of fixing (or even driving!) an M37 or FFPW wouldn't notice that something was wrong locking diff or not. Field removal of a broken rear axle is as easy as it gets with these trucks. People who continue to drive on broken axles, and then further damage other parts will get no sympathy from me. It takes 10 minutes to remove a broken axle - there is no excuse for for excessive driveline damage due to lazyness."

With an open differential on the rear axle in 2WD, you will notice as you will not be able to get anywhere. But if you are in 4WD or the broken axle is in the front, you may not notice anything until you actually need the traction on all wheels because the wheels and axleshafts will just follow along, making no noise.
With a Lockrite, even harder to notice as the broken axleshaft will just freewheel, not giving any indication that anything is wrong.
Then you are most likely to get the scenario with the rolling truck with the engaged park brake. You might hear the ratcheting noise of the broken driveshaft as it rolls down the hill.

But its too late then, is'nt it?

Marius

PS I see in the brochure its called LOCK-RIGHT, not lockrite.

[Charles Talbert]

I don't have time to argue, however the facts remain

Mr Yota, I'm not questioning your description of how a lock-right functions as I'm all too familiar. I will say that you need to go back & read my post again. My reference to issues is mainly after 1 shaft is already broken, the condition unknown by the operator, & the end result. If you think you can't keep right on going on a hard surface & not be aware 1 shaft is gone, well I guess I'd have to say you are wrong, misinformed, not had it to happen to you, just not being truthful, in denial, take your choice. As long as all is in tact & functioning correctly, Lock-Rights do OK other that some excessive tire wear. You feel free to use what ever works for you, whatever you like, the cheaper option, etc, it's your truck. I don't know how many trucks you have used lock-rights in, we have installed many over 20+ years, most being before the ARB's came about for the M37. I was steering my customers away from using them unless they really had a special need long before ARB's came along as I had already seen the adverse effects that were possible. I still install them, but only on special request & after sharing the down side with the customer so they are fully aware. You can say I'm wrong or whatever you want, the bottom line is this, I know many of the issues they can bring about that are very real & costly possibilities if not probabilities. I believe seeing is believing, I've had opportunity to see several catastrophies. If your chance to view one hasn't come yet, keep the faith, I feel sure you will get your chance in good time. Where you are really missing it is right here; that is posting messages saying others are wrong based upon it hasn't yet happened to you. I have customers who have run lock-rights for years trouble free as far as I know, I haven't received complaints. I also have customers who haven't been so fortunate as I have described. I installed some of the first ARB's that hit the market in the US, I saw straight away it was a far superior unit for a number of reasons. The huge ++ factor being the ability to disengage it when not needed. We advertise our services as doing what our customers specify, that's exactly what we do here every day. I am also well informed on specific issues that I can inform our clients in their best interest, lockers are one of those issues. You might take a minute to give that some thought instead of being such a diehard concerning lock-rights. If you choose not to heed the warnings, that's up to you entirely, give the rest who may read these post the same option to make their own choice. Everyone deserves to be informed of the risk if there are possibilities before they spend their $$$.

Wow!! You really are misinformed & I can tell you have been the luckiest man alive or either very untruthful. I expect the later when you speak of how easy replacing a broken shaft can be in the field. In the overwhelming majority of cases, they break right above the splines, usually leaving the broken & twisted splined section in the side gear & most of the time it doesn't allow for an easy removal with splines being twisted. I've had to tear many down all the way to removing the side gear & drive out the broken piece or pieces. Anything is possible, but hardly ever does a clean break happen making for easy removal occur. If it did happen that way, there will be some small metal pieces left in the diff to circulate & destroy. You speak of this being so simple & you never mention the need to remove the diff from the axle housing to clean out stray metal pieces or the fact that these pieces can't be removed by draining the oil. Mr. Yota, all I know to say after reading your last paragraph is that you have told all readers just how little you do know about the subject on which you have claimed to be so well informed. If this is the way you do it, you are headed for the catastrophy of catastrophies head long.

[MasterYota]

What scared me from the lockrites and to choose ARBs instead was the pulling of heavy loads on hard surfaces. The lockrite will transfer all tourqe through only 1 axle shaft and put a considerable strain on it, while the ARB, working as a stock differential, would evenly distribute the tourqe on both axleshafts. Correct me if I am wrong.
Marius

Apparently I've misread your question. Are you trying to compare the function of a locker to an open differential? Or an open diff to an open diff?

Also, a lock right functions on the basis of input torque. As the ring gear turns, the crosspin forces the two halves of the lockrite apart to engage the side gears. This engagement loads both shafts equally so long as input torque remains in effect. This is true when the throttle is applied when traveling straight or when cornering. When cornering, the outside wheel travels more distance - the spring design of the locker will allow that side to disengage and turn faster than the ring gear to make the corner. This disengagement is usually the clicking noise that most people hear. That being said, I suppose that a point for your argument could be made. However, the input into the axle shafts from the engine dosen't change or mulitpy at the wheels because one wheel is off the ground, or unhooked from the driveline. The diff is working with a set input figure.

If for numbers sake there is 100 ft.lbs. being applied to each axleshaft, on a chassis dyno, there would be 100 lbs measured at both wheels. If you lift one tire off the dyno and run it, you would still have 100 lbs. going to the opposing wheel, not 200 lbs. The loss of load on one side will not multiply the input on the otherside. Instant shock load is what usually breaks axles. Momentum either from a spinning tire, sudden transfer of load from a moving tire, through the diff to a non moving tire, or excessive lateral twist due to the tire being unable to turn are the usual root causes or failure. Axle age and fatigue also play a role.

I'm happy for you Marius, that you where able to get an ARB - I won't deny that it is the superior differential. And thanks for the grammer lesson, here's one in return: Torque is the correct spelling; Tourqe is incorrect. I don't always trust Wiki by the way - to many inaccurate sources providing suposedly acurate information.

Charles - I have never, to my knowledge indicated to you that you have ever been wrong about anything. I merely disagree with some of your opinions.. Its my right to have a different opinion than you. I don't appreciate your slanderous tone however. And your right, I don't have the singular specific amount of experience with these trucks that you've got. What I do have is 20 years of exerience as an offroad enthusiast, doing my own work, my own fabrication, and my own reseach. I don't know everything (like you seem too) but I do keep an open mind. I will not tolerate being preached at by you.

You tout the greatest things about the ARB EXCEPT for its availability. You rant the benifits of choosing a device that isn't available 99% of the time. When the ARB is unavailable what do you reccomend then?

As for how to fix or repair a broken axle shaft - Do I really need to explain every little step? Are the M37 diffs so fragile that they can't handle a little metal flake for a couple of miles? I wouldn't perform a complete diff service on the side of the road here Charles. I'd limp the truck to somewhere safer, and more appropriate. Axle shaft failure rarely happens in the driveway.

Charles I call it like I see it, with my benefit of my experience, and with honesty. I don't appreciate be called dishonest or untruthful. You might as well have called me a liar. If you weren't 2000 miles away, I'd come see you and we'd have a little chat about that. Others on this site will defend your tone with the excuse of "thats just the way you are". I personally think it sucks.

Have a nice day

[Marius]

MasterYota,
In my use, I saw the need for a locking differential. It being the lockrite or the ARB, both would serve my need offroad. That is not my concern. My concern is when doing heavy towing on the road when I dont need the locking function. I never said that you multiply the tourqe with the lockrite. What I said was that with the lockrite, 100% of the tourqe (not more) is on only 1 axleshaft, and not evenly distributed on both as with ARB and stock. The tourqe is the same but 2 shafts handle it better than 1. Wikipedia or not, find any source you like and you will see its the laws of physics.
If I had installed lockrites, I would also have to limit my heavy towing. But since that is what I often use my truck for, stock differential would be a better option for me. When the ARB became available, I could do both towing and offroad without giving up the other.
Ii is my opinion that this is such an important downside to the lockrite that people should be aware before they decide.
Your grammar is just fine as far as I am concerned. I did not get that point.

Marius

[Charles Talbert]

OK, the line about Marius & me stating incorrect info concerning a lock-right has now been removed from the first line of your message #39, I can only assume you went back & edited it out after being confronted about it. That line that is no longer there is the reason you got the reply that you did from me. To clear the air, let me say this, I only state info concerning subjects on which I have rock solid information. I pass that info along in a straight forward no nonsense fashion, I don't sugar coat, it is what it is. Many seem to take offense at that for seemingly no reason sometimes & take it as being disrespectful for whatever reason. I'm not trying to offend, only to get to the bottom of the current issue. If someone has a situation that could have more than 1 solution, I may make a suggestion to check out various points, I may say nothing at all. If you are offended to the point of wanting to come & visit, well the door is open or feel free to give me a call by phone, I'll stop what I'm doing to talk with you.

The Lock-Right & the ARB are the only 2 choices for the M37. Dan has said some ARB's will be available shortly for interested buyers. If you like your Lock-Right, that's great, I hope your future with it is good. I also think that people who may be reading this thread that are considering making a purchase of a locker deserve to hear both sides of the album concerning Lock-Rights.

[MoparNorm]

I'm happy for you Marius, that you where able to get an ARB - I won't deny that it is the superior differential

I'm glad that we finally got to that conclusion, after 10,000 words and 45 entries, after all that was my original point....= )