Wrecked my TTB

FuzzFace2 wrote

....  Driving when dry out any "little" power around a corner would lock and the tires would make noise....

I appreciate the rest of your post, with your observations and comments.  But this one sentence is where many people get confused about how automatic lockers work, and it gets them thinking about them the wrong way, leading to people thinking they understand them but really don't, so they find automatic lockers unpredictable.

The locker locking was not what made your tires make noise.  It was the fact that it was UNLOCKED that made your tire (singular) make noise.  Going around a corner you're only driving the inside rear tire, the tire with the least weight on it.  Any little power will slip that tire and it will make noise.  But the locker isn't engaged (yet).

The Ken Brock impersonation come from when that spinning inside tire catches up to the outside tire.  That's when the locker locks.  And at that point you can spin BOTH rear tires so things get fun (or not ).

Rusty_S85 wrote

....  I think the majority of people out there wouldnt like a locker period even an automatic style locker.  Most people today are spoiled with modern technology...

I completely agree that most people wouldn't like an automatic locker.  They are really obnoxious!  But they are also really effective, and the few people who value the effectiveness enough are very willing to put up with their obnoxiousness.  And putting up with it is no where near as hard as some would have you believe.  But they aren't for everyone.

And most people would be fine with a selectable locker because most people wouldn't know it's there or know how to use it, so it would just be an open differential to them.

Rusty_S85 wrote

....  Of course, the open diff is more of a safe bet when you are unsure of a diff style.  I actually settled on the TrueTrac some 6 years ago and considering I am buying a Currie third member to change my gear ratio so all I have to do is pull my axles out a bit pull the OE third member and throw in the new one and be back on the road vs having my OE third member rebuilt, I have an option of a OE limited slip or the truetrac.  Price wise when I last looked they were both about $1,200 if I remember right.  I figure it would be better for me with my limited off road use but should provide better street mannerism for me especially with me driving on winding back country roads at 60 - 75 mph.

I think you'll be very happy with a TrueTrac.  It's completely invisible in almost all driving.  Its only "bad manners" is like Gary pointed out.  It is possible to spin both tires with it (vs an open diff that generally only spins one), so you can swap ends accelerating on a slippery surface.  But even that isn't harsh or abrupt like it is with a locker, so it's usually very easy to predict and deal with.

Rusty_S85 wrote

I was going off how the U-joints are typically the weakest link when it comes to power with traction.  Maybe its different when dealing with a truck and a hotrod build that has slicks loading up going down the strip.

U-joints are the weakest link, but they aren't subject to the additional torque multiplication of the rear axle gears.  So they only need to be about 1/4 as strong since they only see about 1/4 the torque.

And again, it's most likely to be a shock load on launch or something that would break anything.  There aren't any severe loads from a locker when just driving, even if it's at 75 mph on a winding road

Rusty_S85 wrote

But now I am kind of curious on the automatic lockers how they would feel driving a short wheelbase flareside with one.  Ive driven cars with them but never something like a truck like mine with very low weight on the rear axle.

When you say you've driven cars with automatic lockers are you talking about limited slips?  Because no car company ever puts an automatic locker in, and other than for drag racing it's hard to imagine people doing it aftermarket.

Nothing Special wrote

When you say you've driven cars with automatic lockers are you talking about limited slips?  Because no car company ever puts an automatic locker in, and other than for drag racing it's hard to imagine people doing it aftermarket.

Im talking about aftermarket automatic lockers.  At work we get a lot of hotrods that people throw insane parts in that really arent street friendly.  Some of them the owners installed auto lockers in them.

That is why I dont feel a locker would be right for myself, I just never been fond of them when I drive cars in for work at the shop that have them.  Hell we had one that had a gear drive timing set we spent months trying to talk the guy into letting us pull that thing off and throw a regular double roller timing set which he finally agreed to.  Then he was so happy about it couldnt believe how quiet the engine was without that obnoxious whine of the gear drive timing set.

Lot of our customers at work they are magazine readers, they read them and then want whats in the magazine even if we know they wont like it.

Rusty_S85 wrote

Im talking about aftermarket automatic lockers.  At work we get a lot of hotrods that people throw insane parts in that really arent street friendly.  Some of them the owners installed auto lockers in them....

I get that

Rusty_S85 wrote

....  Lot of our customers at work they are magazine readers, they read them and then want whats in the magazine even if we know they wont like it.

I get that too!

Rusty_S85 wrote

....  But now I am kind of curious on the automatic lockers how they would feel driving a short wheelbase flareside with one.  Ive driven cars with them but never something like a truck like mine with very low weight on the rear axle.

If you haven't liked them in a car you probably wouldn't in your truck either.

I've had rear lockers in a CJ5 with a manual trans, an F-150 SuperCab short box with an automatic and my '71 Bronco, first with an automatic but now with a manual trans.  The locker is most obnoxious in a shorter vehicle with a manual trans.  The inherent softness of an automatic trans damps out a lot of the harshness of an automatic locker.  And the torque steer are you get on and off the throttle during shifts is very noticeable with a manual.

And a long wheelbase does two good things for you.  It gives more leverage to dampen the torque steer, and it's a lot slower to swing out so the sudden fishtail when you break both tires loose is a lot less sudden.

The main thing with the light weight on the rear axle would be like Dave was talking about with his Gremlin.  Even with both tires turning you still might not go anywhere in snow (but hey, at least the back end will be sliding all over the place!).  And it would be extremely easy to spin the inside rear tire when on the power in a curve.  So not really a plus!

Nothing Special wrote

FuzzFace2 wrote

....  Driving when dry out any "little" power around a corner would lock and the tires would make noise....

I appreciate the rest of your post, with your observations and comments.  But this one sentence is where many people get confused about how automatic lockers work, and it gets them thinking about them the wrong way, leading to people thinking they understand them but really don't, so they find automatic lockers unpredictable.

The locker locking was not what made your tires make noise.  It was the fact that it was UNLOCKED that made your tire (singular) make noise.  Going around a corner you're only driving the inside rear tire, the tire with the least weight on it.  Any little power will slip that tire and it will make noise.  But the locker isn't engaged (yet).

The Ken Brock impersonation come from when that spinning inside tire catches up to the outside tire.  That's when the locker locks.  And at that point you can spin BOTH rear tires so things get fun (or not ).

When the Lock Right was for a lack of a better word "free wheeling" or coasting around a corner you could hear the locker ratcheting or clicking and no tire noise. As soon as you gave it any power it would not ratchet or click and the tires would make noise.
At that point when not ratcheting or clicking and the tires would start to make noise to me the axles are locked and act like a spool at that point. Weather 1 tire is moving faster to catch up or the other slowing down a tire still need to slip as they are in 2 different arcs and only happens when locked.
Unlocked they are free to move at different speeds around corners.

I also thought any time a locker was under power the axles were locked like a spool.
That is why a locker in a rock climber can have 1 tire in the air and the other tire will get power 100% of the power. Put both tires on the ground and they share power so both have 50% of the power going into the axle housing.

I will say I knew what I was in for before I installed the locker in the short wheel base car with no weight on the drive tires.
I can also tell you if 1 tire has little to no traction it will "bulldozer" turn big time.
Drag racing there must have been a little water under 1 of the tires and when the light turned green and I hit it and the car turned right to the start tree! After I got it under control I thought I spun a axle hub as the axle and hub are pressed together with a large nut but both were still in good shape and why I guess water.

I will also say I don't think I would ever install a locker in a car or truck I would be driving in ice & snow because of how the Lock Rock works but I like the 2 LS I had from the factory in my trucks on ice & snow.
Just my .02
Dave ----

FuzzFace2 wrote

When the Lock Right was for a lack of a better word "free wheeling" or coasting around a corner you could hear the locker ratcheting or clicking and no tire noise. As soon as you gave it any power it would not ratchet or click and the tires would make noise.
At that point when not ratcheting or clicking and the tires would start to make noise to me the axles are locked and act like a spool at that point....

A common misconception because the things happen pretty close to the same time.  But there's no way for the locker to engage while the inside tire is going slower than the outside tire.  So it can't engage "as soon as you gave it any power."  It won't engage until the result of adding the power breaks the inside tire loose and the inside tire catches up to the outside tire.  It might take less than a second, but the sequence is add power, break the inside tire loose, inside tire catches up to outside tire, then locker reengages.

FuzzFace2 wrote

I also thought any time a locker was under power the axles were locked like a spool....

Another common misconception (which is often held by writers in 4WD magazines).  Automatic lockers know nothing about whether you are putting power to it or not.  All they know is relative motion of the two sides and the carrier.  They will always allow one tire to go faster than the carrier and they will never allow either tire to go slower than the carrier.

FuzzFace2 wrote

That is why a locker in a rock climber can have 1 tire in the air and the other tire will get power 100% of the power....

 

Yes but no.  The locker will drive the one tire that's planted, giving it 100% of the power, because it will never allow either tire to turn slower than the carrier.   But if someone were to grab the tire that's in the air and turn it faster they'd find that it would turn easily.  Because the locker will easily disengage any time a tire tries to turn faster than the carrier.  Power has nothing to do with it

FuzzFace2 wrote

...Put both tires on the ground and they share power so both have 50% of the power going into the axle housing....

Possible, but only if both tires are turning exactly the same speed.  If you are turning at all, or if one tire is a little different diameter than the other then one tire will be trying to turn a little faster than the other  and the locker will disengage.  That's why you usually get at least a little torque steer any time you get on or off the throttle.  So usually an automatic locker is sending all of the power to one tire (unless that tire is slipping).

FuzzFace2 wrote

...I will also say I don't think I would ever install a locker in a car or truck I would be driving in ice & snow because of how the Lock Rock works but I like the 2 LS I had from the factory in my trucks on ice & snow.
Just my .02
Dave ----

A lot of people agree with you on that.  I'm just not one of them.  And that's fine.  That's just opinions and preferences.  I don't expect everyone to be the same there.

Bob - Thanks for your detailed explanations on this.  I really appreciate the time you've taken and the in-depth knowledge you have.  I'm learning a lot from this.

Gary Lewis wrote

Bob - Thanks for your detailed explanations on this.  I really appreciate the time you've taken and the in-depth knowledge you have.  I'm learning a lot from this.

Indeed! Thanks to you Bob, and all for contributions and experiences.

I had a couple of paragraphs typed out earlier and got sidetracked looking something else up and when I came back it was gone. I was too lazy to type it again, but worked out well, I read the rest.

Really learned a lot. Realized I had a lot of the misconceptions you pointed out.

Now that I learned how they work, if I was to put something in my 86 I would really like to try a Detroit Locker. I had a clutch type put in my 96 F250 and I didn’t really like it. Interestingly I like the stock clutch type in my 92 Bronco.

Edit: I like the G80 in my wife's Suburban. The MLocker or gov loc, I’ve seen them called. People will say they will grenade, but for everyday driving I like it.

I will repeat my warning: automatic lockers are obnoxious and definitely not for everyone.  I value the performance and don't mind having one in my Bronco.  And I didn't mind having one in my F-150.  But I did decide not to put one in my F-250.  Not saying you won't like it overall, but it's certainly no sure thing that you will.

If you are are thinking about putting a locker in a truck that currently has an open diff you might want to consider a lunchbox locker.  They work essentially the same as the more expensive automatic lockers (different mechanism but the same operation).  But the purchase price is lower and you can install one yourself in an afternoon, without needing to set up gears.  And what might be better, you can take it out and go back to an open diff in an afternoon too if you decide it's not for you.  But you need to have an open diff to start with.


On the G80 (aka Eaton M-locker, Gov-Lock or less charitably Gov-Bomb), I've never driven one, but it sounds pretty good.  It's an open diff (I think) most of the time, but if it senses too big a speed difference between the two tires it will lock.  So it wouldn't have the torque steer in normal driving that makes an automatic locker obnoxious.  And it drives both tires in corners like an open diff so it doesn't have the obnoxious feature of an automatic locker of only driving the inside tire making it easy to break it free.

The potential downsides I can see are that, like any traction-aiding diff, it can make it easier to spin out because you can spin both back tires instead of only one.  And while I don't know by experience, it would seem to me that it might happen more abruptly when the locker suddenly engages than it would with either a gear-type or clutch-type limited slip.

And that abruptness leads to its other downside as well.  As you noted, they don't have a great reputation for reliability.  Unlike an automatic locker that always engages when both sides are going the same speed, a G80 always engages when one tire is already spinning, so it slams that tire to a stop.  It evidently is built well enough to handle that most of the time in typical use, but it apparently isn't overbuilt, and can blow up, especially if paired with lower gearing and bigger tires.

Thanks, I appreciate the tip on the lunchbox lockers, that’s a great idea as you said it’s easy to go back. And not as expensive.

IMHO, people who grenade the G80 are doing exactly as you said, big tires, gears and wheeling with it. I don’t think it’s made for that at all. I haven’t found any bad manners, in fact I wouldn’t even know it’s there unless I read the load sheet or peeled out in gravel. Which I did both, I didn’t feel or hear anything, both tires broke loose and she took off!

Ours still works and we have around 230k on our Suburban. I assume they are proprietary with GM as I haven’t seen them available anywhere.

Great! Now I’ll be off looking into lunchbox lockers!

Bob - Would you be willing to do a writeup in the documentation section on differentials?  I think it would go in the page at Documentation/Axles & Differentials and would be a tab called How Differentials Operate.  Or maybe Differential Operation.  Or Differential Options.  (IOW, I don't know for sure, so need some help.)

I'm seeing it as a overview of how each style operates as well as a pro's and con's of each.  Include pictures, diagrams, links, videos, etc.

Would that be something you'd be willing to do?

grumpin wrote

.... I haven’t found any bad manners, in fact I wouldn’t even know it’s there unless I read the load sheet or peeled out in gravel. Which I did both, I didn’t feel or hear anything, both tires broke loose and she took off!...

Good to hear.  I don't know what type of clutches the G80 uses or what speed difference they limit to.  Most locker clutches are very solid and therefore very harsh, so I expected there'd be something pretty noticeable when it engaged.  But either they do use a clutch that will slip into engagement or else the limit speed is so low that it works smoothly with a positive clutch.  Either way, nice to know it works so seamlessly for you

grumpin wrote

.... I assume they are proprietary with GM as I haven’t seen them available anywhere....

They must be.  They're made by Eaton but Eaton doesn't feature it on their "aftermarket differentials" page.  It only shows up on their "original equipment differentials" page.

And for what it's worth on the various names it has:

M-Locker is what Eaton (the company that makes it) calls it

G80 is the GM order code, so that's how it shows up on the window sticker, and it's what people started calling it

I don't know where the name Gov Lock started, but it makes sense as it's a locker with a governor that limits the speed difference

Gov Bomb is the obvious spinoff from Gov Lock by people who think they break too easily.  But as noyed above, they seem to hold up fine if not abused.  It's just that they aren't overbuilt, so they can't take much abuse

Gary Lewis wrote

Bob - Would you be willing to do a writeup in the documentation section on differentials?  I think it would go in the page at Documentation/Axles & Differentials and would be a tab called How Differentials Operate.  Or maybe Differential Operation.  Or Differential Options.  (IOW, I don't know for sure, so need some help.)

I'm seeing it as a overview of how each style operates as well as a pro's and con's of each.  Include pictures, diagrams, links, videos, etc.

Would that be something you'd be willing to do?

I could probably do something like that.  I've already written up an overview in this thread on FTE.  I'd want to rewrite some of it because I've learned more since then, but it gives me an easy starting place.

I'm not sure that I can promise much on pictures, diagrams, links, videos etc. though.  I have a few links to other people's videos and explanations that I think are pretty good, so I can use those.  But that's not a lot, and I'm not promising that I'll dig enough to find a lot more.

The FTE thread is a very good start.  In fact, we could use most of that just the way it is.

I'm thinking of something like this:

Intro: Tells who you are and why you are qualified to write this - exactly as you've done

    Rear Diff tab:

        Type 1

        Type 2 tab

        Type 3 tab

        Types 4 - n tabs

    Front Diff tab: Maybe everything you have in that post on the one tab?


If you want I could create a page and use the info from the posts in that thread to give you a starting point.  Thoughts?

I just looked at that thread on FTE, interesting. I have only had personal experience with the Ford Traction Loc (in Darth) and a Detroit "silent" locker (in my 1966 GT350) That was interesting to drive until you got used to it. It drove the slower turning wheel and the faster one was prone to unlock with a "bang", straightening out under power, another "bang" coupled with a "tail wag". Straight line, dump the clutch and the car would actually lift the front wheels slightly off the ground (I didn't believe it until a friend who drag raced showed me). The locker plus the ability to lift the front wheels meant that in first you better have the hood pointed where you wanted to go.

The friend did take the car to our local drag strip as we were building an H-modified Chevy Nova with a Clifford built 292 Chevy truck engine and he wanted some seat time in a reasonable fast car (Shelby went mid 12s). It's amazing what nearly 400 hp in a 2800 lb car can do. We also a number of years later found that at 137 mph the front end got light enough to be scary.

https://www.eaton.com/us/en-us/catalog/differentials/mlocker.html

I like the video on how the G80 operates. I forgot they have clutches till you mentioned it.

Gary Lewis wrote

....If you want I could create a page and use the info from the posts in that thread to give you a starting point.  Thoughts?

Just curious about the mechanics of how I would change things from the starting point.  Would it be essentially like a thread where I'd be able to edit it?  Or something else?

Regardless of the answer to that, I'm thinking that I'd want to make enough changes to what I wrote 5 years ago that it might be better if I wrote something new up and we (you?) just posted that.  I could either e-mail it to you or even just post it in a thread that you could pull it from.

We can do it one of two ways.  You can write something up, maybe in Word, and email it to me.  Or I can give you editor access to that page and you can modify it as you see fit.  I suspect that Word will be easier for you as you won't have to learn anything about layout on Weebly, so suggest we do that.

And it will be a page where there's no ability to comment.  Not a thread.

Please take a look now at Documentation/Driveline/Axles & Differentials, then the Bob's Thoughts On Differentials tab.  As said in there, the title of that tab is TBD, and that is just a place-holder.

Gary has discussed how to do this before.
I'm not sure if anybody can, or just admins.

Since the documentation side is hosted on Weebly there are different rules there than here on the forum.  So being an admin on the forum doesn't get you editing rights on Weebly, and vice versa.

I can give editing rights to individual pages on Weebly to whomever, so I could set Bob up as an editor of the Rear Axles & Differentials page.  But then he has to learn how to edit and that's not the easiest thing to do, as I've remembered today while working on the site.