Detroit Locker Failure

[biggin]

Recently the Detroit Locker that I installed twelve years ago started to clunk violently, a bit more often than it used to, when going around corners. Then last night when leaving my driveway it gave an almighty clunk, then again at the next corner, and the next and so forth, and also sometimes on a straight. It seems that it is the locker that has failed but I understand they are supposed to be bulletproof. So, I was wondering if a broken axle is more likely to be the problem. Has anyone had this issue with Detroits? Is there a way I can tell what's wrong Before I pull everything apart?
Anyway, I think I know what I'll be doing this weekend.[bigwhistle]

[DieselLSE]

Even if it's a broken axle you'll still need to pull everything apart. 'Seasy to check, just raise each rear wheel and turn it. With a Detroit Locker, it shouldn't rotate. Actually, now I think about it, probably best to raise the rear axle, disengage the handbrake and start rotating prop shaft and wheels to help diagnose. Have a good weekend!

[Slunnie]

I’m not sure they’re bulletproof. I think in the past they’ve had a reputation for being brittle in many respects and breaking when an axle snaps.

Hopefully no bits come out with the oil and its just something simple.

[V8Ian]

Is it a locker or unlocker?

[Blknight.aus]

check your flanges first.

[biggin]

Is it a locker or unlocker?

It’s an unlocker

[biggin]

check your flanges first.

Thank you, but what part is the flange.
My mate reckons simply replacing the oil might fix it but I’m extremely skeptical about that.

Oh, you mean on the driveshaft don’t you?

[goingbush]

And your still driving it ? After the first unusual clunk I'd have had it up on axle stands and dissasembling till I found the problem, each succesive drive can be adding to the repair bill exponentially. But as suggested probably a flange , that would be a bullet dodged. But If you don't know what part the flange is I think your the wrong guy to be on the spanners.

And no, your mate is wrong , replacing the oil wont help.

[Blknight.aus]

Thank you, but what part is the flange.
My mate reckons simply replacing the oil might fix it but I’m extremely skeptical about that.

Oh, you mean on the driveshaft don’t you?

I ment the axle flanges

[Red90]

I ment the axle flanges

Disco 2…..

[biggin]

Jacked her up onto axle stands and drained the oil. Couldn’t see anything abnormal. Just the usual amount of fine metal particles on the drain plug magnet and a lot of milky green oil.
I couldn’t turn the wheels, so assume the axles are okay.
I’ll put the centre differential in neutral and try turning the prop shaft. Not sure doing that will tell me much.

[goingbush]

milky oil means its got water in it

[Blknight.aus]

Disco 2…..

pull em to check the internal splines.

[Red90]

Jacked her up onto axle stands and drained the oil. Couldn’t see anything abnormal. Just the usual amount of fine metal particles on the drain plug magnet and a lot of milky green oil.
I couldn’t turn the wheels, so assume the axles are okay.
I’ll put the centre differential in neutral and try turning the prop shaft. Not sure doing that will tell me much.

Sounds like the locker is broken. You should be able to turn a wheel forward.

Sucks that it is a Disco 2 as pulling it part is a pain.

[biggin]

Sounds like the locker is broken. You should be able to turn a wheel forward.

Sucks that it is a Disco 2 as pulling it part is a pain.

No matter. I installed it in first place,
so I’ll just put the old diff back in.
I’m not as adventurous as I used to be, so probably won’t miss it.

[biggin]

And your still driving it ? After the first unusual clunk I'd have had it up on axle stands and dissasembling till I found the problem, each succesive drive can be adding to the repair bill exponentially. But as suggested probably a flange , that would be a bullet dodged. But If you don't know what part the flange is I think your the wrong guy to be on the spanners.

And no, your mate is wrong , replacing the oil wont help.

Thanks Goingbush, I’m not still driving it, but thanks for the encouragement.
It’s this sort of useless response that must discourage many people from this site.

[Red90]

No matter. I installed it in first place,
so I’ll just put the old diff back in.
I’m not as adventurous as I used to be, so probably won’t miss it.

I would switch to a truetrac or ashfroft atb. They work well with the traction control. The stick diff is really weak so is a recipe to leaving you stranded.

[biggin]

I would switch to a truetrac or ashfroft atb. They work well with the traction control. The stick diff is really weak so is a recipe to leaving you stranded.

That’s my plan. I’ve a TruTrack in the front and works well.
Pulled the Detroit apart today, found many teeth broken off internally.
Original diff is installed back in the housing, dialed in and ready for installation tomorrow.
Not a bad job really. Just a bit smelly. At least I’ll be able to get to work on Monday.

[biggin]

Job done, back on the road. Still don’t know what the flange is all about though.
I don’t get many weekends working on the D2 as they are so reliable. Quite enjoyed it.
I know it’s probably only a 4 hour job for the professional, but I like to take my time.

[Blknight.aus]

Still don’t know what the flange is all about though.


The flange check is for axle condition,

in the d1/deefer version the axle end at the flange is a weak point, and in about 40% of the diffs I've seen with the symptoms you've described its a stripped spline stepping over that causes the noise. In the later versions early wear in some instances turn up on the inner side of the axle.

as you've got to pull the axles to drop the diff out you can check them first..

The remaining issue thats not the center itself is the CWP stripping out. With the axles out checking the rotation of the input flange will clue you in as to what else might be wrong BUT, if the axles and flanges dont show damage the diagnostics benefit of knowing if its likely to be the center or the CWP setup really only has advantage knowing what to quote the customer.

[Red90]

D1s don’t have flanges. The shafts are one piece.

D2 hubs are internally splined.

[Slunnie]

They’re pretty easy on the splines and don’t really wear them because the clamping force on the axle from the semi floating setup probably stops most of the movement. If anything they just snap beside the flange which is on the axle.

http://www.slunnie.com/coppermine/albums/userpics/10001/normal_P7040002.JPG

[Red90]

D2 axles are full floating. Semi floating means the axle supports the hub and vehicle weight.

[Slunnie]

D2 axles are full floating. Semi floating means the axle supports the hub and vehicle weight.
Hmmm, thats one definition.

D2 is semi-floating - the axle and flange as an item are just 2 piece and bolted and the flange runs on the inside of the bearing as per semi float. It doesn't have its own stub axle that the hub runs over in isolation and you cant drive on it without an axle in it like a full float.

[Blknight.aus]

Guys, the half shaft has 2 ends....


both ends are splined,

if your splines looked like the ones pictured in the link below, thats an indicator to your problem IF your axle, side gears, drive flange/drive hub was the issue.

Wheel tech -Inspecting worn hub splines (wire wheels) (https://mgaguru.com/mgtech/wheels/wl104.htm)

In a D2 having a fracture outboard of the shoulder you'll get very similar symptoms to what was originally described. if the splines have stepped its the same effect as for a defender stripping the splines.
in a D1, assuming it hasnt had a defender style axle setup fitted if the shaft fractures at an angle inside the stub axle you get the same experience.
In a defender setup you can get spline wear as per whats shown above to cause the issue


IF you have odd wear on the inboard side, theres a handfull of issues that it could have been, bent axle housing, bent stub axle, stressed axle and yes, I've seen stripped but not snapped splines on the inboard side of the axle. and Ive seen bent splines like these

Castlemaine Rod Shop custom bolt-in nine-inch diff build (https://www.streetmachine.com.au/features/castlemaine-rod-shop-building-custom-bolt-in-nine-inch-diff)

with the next stage of that being a nice neat fracture at the bend.... (and if it wedges in its a nightmare to pull the diff center.)


In the d2, generally to the best of my knowledge there is always an underpinning problem if the axle has issues outboard of the shoulder, but theres no discouting a manufacturing defect.

[discorevy]

D2 axles are full floating. Semi floating means the axle supports the hub and vehicle weight.


Hmmm, thats one definition.
you cant drive on it without an axle in it like a full float.

Red90 has the correct definition, the D2 has full floating axles.

The axle bears no weight on a D2 but you can drive on it without an axle in it, it would just be messy unless you drained the oil from the diff or sealed the housings .

[Slunnie]

Red90 has the correct definition, the D2 has full floating axles.

The axle bears no weight on a D2 but you can drive on it without an axle in it, it would just be messy unless you drained the oil from the diff or sealed the housings .
Semi floating, its just a 2 piece setup, the axle isn’t even floating to start with. Without the axle, the flange isn’t mounted into the bearing properly, its only a press fit so you wouldn’t drive on it, but thats the reason why the axle and flange is 2 piece so that it can be assembled with that type of bearing and then when the axle/flange are bolted together, then the assembly is secure - with the flange as a part of the axle rather than the hub. I see the conflict in view and even if the flange comes assembled with the hub bearing, its secured to the axle, not to the bearing.

http://www.slunnie.com/coppermine/albums/userpics/10001/D2_rear_hub_assembly.JPG

[Red90]

It is a full floating axle.

[Slunnie]

It’s not even floating. :lol2:

[DiscoDB]

It’s more like a three-quarter floating axle but with an inverted double bearing wheel hub.

It has some attributes of both the semi-floating axle and fully floating axle, but it is not truly either.

https://uploads.tapatalk-cdn.com/20240116/9e6bfe453d7cb87c065ae385a2795f7a.jpg

It uses the pronouns they/them. [emoji851]

[Red90]

No. It is a full floating axle. The hub is a unit bearing.

Stop and think if there was a drive flange instead of the hub being internally splined. It would work exactly the same way.

[101RRS]

Does it matter - the point was to check the splines on the flanges on the hubs where the axle drives the wheels.

The issue has now been over taken by events as the locker is removed and the cause found.

Move on.

[Slunnie]

No. It is a full floating axle. The hub is a unit bearing.

Stop and think if there was a drive flange instead of the hub being internally splined. It would work exactly the same way.

Its just a 2 piece semi floating axle. As said, the axle isn't even floating. A floating axle is an axle that is loose which is what float is, albeit the axle float is retained or limited - you can measure the end float if you like. A d2 axle doesn't have float because it is bolted flange and presses the bearing. The load points aren't what define what a floating axle is, it is whether the axle floats within the system. The D2 axles doesn't do this at the hub end which is why it is called a semi-float - semi float because it floats at the diff end. The only difference between a D2 semifloat and a textbook semifloat is the bearing runs on the flange in the Disco2 and not the shaft which is a far better setup as it doesn't bend the axle, the axle just retains the hub, but if you snap the axle between the halfshaft flange and the wheel flange then it all comes apart - unlike in a full float setup where the axle carrys no load apart from torque and the hub is retained on a spindle and the axle is free to float between its captive limits.

Look, I'm really not invested in what people call it, it makes no difference to either of us - the axle just isn't floating in the system, there is no way that it can actually float.

http://www.slunnie.com/coppermine/albums/userpics/10001/D2_rear_hub_assembly.JPG

Actually wiki has a good explanation of floating/semi-floating because it identifies as an engineering text. :lol2:
Axle - Wikipedia (https://en.wikipedia.org/wiki/Axle#Full-floating_vs_semi-floating)


A full-floating axle carries the vehicle's weight on the axle casing, not the half-shafts; they serve only to transmit torque from the differential to the wheels. They "float" inside an assembly that carries the vehicle's weight. Thus the only stress it must endure is torque (not lateral bending force). Full-floating axle shafts are retained by a flange bolted to the hub, while the hub and bearings are retained on the spindle by a large nut. In contrast, a semi-floating design carries the weight of the vehicle on the axle shaft itself; there is a single bearing at the end of the axle housing that carries the load from the axle and that the axle rotates through. To be "semi-floating" the axle shafts must be able to "float" in the housing, bearings and seals, and not subject to axial "thrust" and/or bearing preload. Needle bearings and separate lip seals are used in semi-floating axles with axle retained in the housing at their inner ends typically with "c-clips" which are 3/4-round hardened washers that slide into grooves machined at the inner end of the shafts and retained in/by recesses in the differential carrier side gears which are themselves retained by the differential pinion gear or "spider gear" shaft. A true semi-floating axle assembly places no side loads on the axle housing tubes or axle shafts.


Axles that are pressed into ball or tapered roller bearings which are in turn retained in/on the axle housings with flanges, bolts, and nuts do not "float" and place axial loads on the bearings, housings, and only a short section of the shaft itself that also carries all radial loads.


The full-floating design is typically used in most 3/4- and 1-ton light trucks, medium-duty trucks, and heavy-duty trucks. The overall assembly can carry more weight than a semi-floating or non-floating axle assembly because the hubs have two bearings riding on a fixed spindle. A full-floating axle can be identified by a protruding hub to which the axle shaft flange is bolted.


The semi-floating axle setup is commonly used on half-ton and lighter 4x4 trucks in the rear. This setup allows the axle shaft to be the means of propulsion, and also support the weight of the vehicle. The main difference between the full- and semi-floating axle setups is the number of bearings. The semi-floating axle features only one bearing, while the full-floating assembly has bearings on both the inside and outside of the wheel hub. The other difference is axle removal. To remove the semi-floating axle, the wheel must be removed first; if such an axle breaks, the wheel is most likely to come off the vehicle. The semi-floating design is found under most 1/2-ton and lighter trucks, as well as in SUVs and rear-wheel-drive passenger cars, usually being smaller or less expensive models.


A benefit of a full-floating axle is that even if an axle shaft (used to transmit torque or power) breaks, the wheel will not come off, preventing serious accidents.

[Slunnie]

It’s more like a three-quarter floating axle but with an inverted double bearing wheel hub.

It uses the pronouns they/them. [emoji851]

I've never heard of that term but it certainly picked up whats going on!

they/them is certainly better than zim/zer! :lol2:

[Slunnie]

Does it matter - the point was to check the splines on the flanges on the hubs where the axle drives the wheels.

The issue has now been over taken by events as the locker is removed and the cause found.

Move on.
Just a thought provoking discussion.

[Red90]

I’m a mechanical engineer. It is a full floating axle.

[Slunnie]

I’m a mechanical engineer. It is a full floating axle.
Semi-float :lol2:

[DiscoDB]

No. It is a full floating axle. The hub is a unit bearing.

Stop and think if there was a drive flange instead of the hub being internally splined. It would work exactly the same way.

Agree that the bearing unit has the attributes of a fully floating axle. This is not what determines if the axle is fully floating.

As Slunnie has pointed out, fully floating refers to if both ends of the axle shafts are free to slide in/out at both the diff end, and drive flange end. The axle drive shaft literally are fully floating at both ends and as such do not carry any side load. The axle shafts carry no other load other than torsional load.

This also allows the axle shafts to be removed in situ without interfering with the wheel bearings, and can even be removed with the wheels still fitted.

The D2 axle shafts can only float at one end, and are used to clamp the bearing hub assembly to the axle casing at the drive flange end, held in place by a 490Nm nut. This fixes one end of the drive shaft to the bearing assembly and hence can not be considered fully floating as it adds lateral (side) load at the ends of the drive shafts.

Fully floating axles the bearing assembly is held in place by retaining nuts on the axle casing, keeping the axle shafts stress free from any lateral (side) forces. The shaft carries no bearing load at all and can have end float at both ends. The axle shafts are essentially fully floating within the axle casing and are not used to retain the bearing assembly. As such, fully floating axle shafts only see torsional load.

Three-quarter floating axles the bearing assembly is also located between the hub and axle casing, but held in place by the axle shaft and hence the axle shaft also carries side loads. Like a fully floating axle, the vehicle weight is transferred direct to the axle casing (not the shaft), but like a semi-floating axle, the axle shaft is fixed at one end and is critical to holding the bearing assembly in place. Three-quarter floating axle shafts see torsional load, and side load (at the ends only).

Semi-floating axles the wheel flange hub and axle shaft are one unit, can not be separated like a three-quarter floating axle, and the axle shaft carries the vehicle weight as the bearings are mounted direct to the axle shaft. Like a three-quarter floating axle, semi-floating shafts only float at one end. A semi-floating axle shaft sees torsional load, side load, and bending loads.

[Blknight.aus]

By the definition of axles its a full floating axle, untill its not...



It’s more like a three-quarter floating axle but with an inverted double bearing wheel hub.

It has some attributes of both the semi-floating axle and fully floating axle, but it is not truly either.

https://uploads.tapatalk-cdn.com/20240116/9e6bfe453d7cb87c065ae385a2795f7a.jpg

It uses the pronouns they/them. [emoji851]

If you have a look at the picture above theres no bearing directly mounted and secured to the axle, the axle does nothing to support the weight of the vehicle, and the axle does nothing to longitudinally locate the hub... except it does.

BUT

if you replaced the axle with a stub like the one thats broken off in the picture below


They’re pretty easy on the splines and don’t really wear them because the clamping force on the axle from the semi floating setup probably stops most of the movement. If anything they just snap beside the flange which is on the axle.

http://www.slunnie.com/coppermine/albums/userpics/10001/normal_P7040002.JPG

the hub is now correctly located.


Heres the fun.

IF you snap the half shaft like the picture above, it works like a fully floating axle the wheel stays where its wanted

If you snap it at the splines, its a 3/4 floating axle, and eventually the bearing assembly works its way out then you loose the wheel and hub, of course the whole lots retained by the brake caliper which amazingly will keep the whole lot in place until the customer gets the vehicle from somewhere south of brisbane central out to ipswich

[DiscoDB]

By the definition of axles its a full floating axle, untill its not...


Agreed - it has many of the attributes of a fully floating axle, except the axle shaft is a key structural element holding the hub flange to the bearing assembly and so also sees side loading which is transferred to the double opposing bearings. This is why it’s not truly fully floating. It turns the splined drive flange end coupling into a fixed/non-floating joint which is under tension.

The bearings can have very minimal float, it is the axle shaft that is not fully floating (until you undo the drive flange nut and it does fully float - and you don’t want that to happen). [emoji33]

I would call it what ever floats your boat. [emoji41]

[biggin]

Anyway, the internals of the locker was a mess of broken teeth, but all the bits were retained inside the locker, so no damage to the rest of the diff or axles, and no trace of metal in the oil. All back to factory spec now.