Wrecked my TTB

[Gary Lewis]

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.

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?

[Nothing Special]

.... 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

.... 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

[Nothing Special]

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.

[Gary Lewis]

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?

[85lebaront2]

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.

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.

[grumpin]

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.

[Nothing Special]

....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.

[Gary Lewis]

....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.

[ArdWrknTrk]

....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.

Gary has discussed how to do this before.

I'm not sure if anybody can, or just admins.

[Gary Lewis]

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.