Is This a Limited Slip Diff?

[CDA 455 II]

This is an '87 Ford Sterling 10.25 dually axle. The axle tag says '4L10'; which would mean yes it is.

Judging from research and pics I've read and seen it is via the square-ish opening vs round opening in said diff.


Just wanted a 2nd/3rd/4th/5th/etc IRATE4X4 opinion.


And how do I tell if the LSD is worn out?

Will it act like an open diff when I lift axle/turn a tire?

 

[Etyler2]

I’m not a Ford expert but it appears that it’s missing a lot of parts to be an LSD.

 

[total newb]

Does it have 3/4" round holes in the ends of the case?

I dont think the 10.25/10.5 have the s-spring like the smaller ones.

Yes a worn tracklok will act like an open when the clutch get worn out.

A traclok is a preload posi. No springs that you would normaly think of. It takes a special tool to assemble a fresh trackloc that is easy to make.

when they get to the point where they basicaly free wheel like an open the gears will have a lot of slop in them and sides will be practicaly floppy in the case

 

[CDA 455 II]

Does it have 3/4" round holes in the ends of the case? From the POV of the pic; the holes are at the top and bottom of the case (in said pic). Is that what you mean?

I dont think the 10.25/10.5 have the s-spring like the smaller ones.

Yes a worn tracklok will act like an open when the clutch get worn out.

A traclok is a preload posi. No springs that you would normaly think of. It takes a special tool to assemble a fresh trackloc that is easy to make.

when they get to the point where they basicaly free wheel like an open the gears will have a lot of slop in them and sides will be practicaly floppy in the case

Is it even worth it to rebuild the LS?



I actually want a Yukon Grizzly or an OX cable-actuated locker.

 

[crazybluerider]

That is absolutely not a limited slip.

It is 100% an open differential.

 

[Wulf]

A little break clean, some plate to reinforce, and some welds and you're good to go

 

[CDA 455 II]

That is absolutely not a limited slip.

It is 100% an open differential.

So the LS was taken out sometime during it's 33 years, then.

If the axle tag is accurate; that is.

 

[Wulf]

So the LS was taken out sometime during it's 33 years, then.

If the axle tag is accurate; that is.

Either is possible. What is the use case and why isn't it welded already?

 

[Aisin]

Definitely open. You don’t know what an open differential looks like?

 

[FlatLander]

85-92 Trac-Loc
All the LS bits are behind the side gears. 72960X for the Spicer clutch kit if you need them.

87-96 Open diff for reference:

 

[92 s dime]

no springs in that tracklok,it uses belville washer behind the spider gears,which push them in and then the side gears get pushed out compressing the clutch packs

https://www.youtube.com/watch?v=fbjPT1JdQKw

 

[Toreadorranger]

Open on the Left, Trac Lok on the right. The case on the trac lok is squared off like that for the clutches to fit behind the drive gear of the spiders.

That is absolutely not a limited slip.

It is 100% an open differential.

Its a Trac Lok, not a open carrier

Definitely open. You don’t know what an open differential looks like?

Apparently you don't

 

[Toreadorranger]

Better picture showing the clutches.

 

[crazybluerider]

Open on the Left, Trac Lok on the right. The case on the trac lok is squared off like that for the clutches to fit behind the drive gear of the spiders.




Its a Trac Lok, not a open carrier


Apparently you don't

I second guessed myself after I posted. 🍺 I wondered about the shape of case but I'm used to seeing some sort of spring in the center as well. Oops.

 

[CDA 455 II]

Open on the Left, Trac Lok on the right. The case on the trac lok is squared off like that for the clutches to fit behind the drive gear of the spiders.



Its a Trac Lok, not a open carrier

Better picture showing the clutches.

So it is a LSD!

This is why I ask IRATE4X4



The square-ish opening gave me a clue, but wasn't completely sure.

 

[CDA 455 II]

Here's another pic of it:

 

[TRINDU]

Its 25+ years old, the clutches no longer clutch.

 

[CDA 455 II]

Its 25+ years old, the clutches no longer clutch.

Yeah; I figured after 33 years in operation it probably has at least 200,000+ miles on it.

 

[bdkw1]

They are usually toast by 80K unless it's all highway miles.

 

[subybaja]

A month late, but I thought I'd add my pic of a LS and the OEM Ford electric locker.. See the clutches under the boogerwelds?

 

[CDA 455 II]

A month late, but I thought I'd add my pic of a LS and the OEM Ford electric locker.. See the clutches under the boogerwelds?

Yup; mine looks exactly like that on the right.