Cleaning and painting up front using elbow grease and a high speed with a wire brush so I'm working on the floor.

Here's the set up:

Front tires off, beams sitting on jack stands.

Here's what it does:

I turn the passenger side axle in forward direction by hand- just that side turns.

I turn the passenger side axle by hand and put mild resistance on the driver side axle and it begins to turn in the same direction as if locked.

Visa versa the other way.

Finally, there is a bead of sealant not factory around the diff housing.

 

IIRC, a limited slip axle would have the tires spin the same direction, and an open differential is opposite directions, so I think that you have limited slip. Whats the door tag code?

 

Unless some body changed it out, it will be an open diff in the front. I don't think that L/S was ever offered for the front, but I could be wrong.

If the axle code has a letter in it then it is a L/S diff, like H-9.

 

Unfortunately the door tag is long gone.. I need to change the fluid so, Im going to suck it out and reservice and if there is an LS in there, I would need to put additive..

 

Depends on what kind of L/S. Only clutch-type needs modifier.

 

Yea with the cover off it'll be pretty obvious, here's my rear LSD:

And an open diff:

 

Thanks guys for taking the time to reply.

I'm trying to avoid pulling the axles,driveshaft and housing just to drain the fluid and look at it if I don't have to. I'm pretty sure that since it locks up very quickly with very little resistance, that it's not a clutch type.
Anyone care to second that motion?

I'm thinking if there could be any problems with putting an additive just to make sure even if it didn't need it, just to be on the safe side.
Thoughts?

This one is a True-Trac, it has no clutches.



This one is a Trac-Lok, it has clutches.

 

Depends on what truck you are talking about, but they did offer a ls front on the 150's. Very rare though.
If both axles turn the same direction then it's limited slip, for a rear. I do not know how it would work for a front. Probably the same.
One way to find out, get on a good slick surface in 4x4 and hammer down.
Just looked it up and if read the door tag it would have a 3rd digit for limited slip front.
Ex, h9b would be 3.55 l/s front and rear.
Also could be a 2 ex, h92, 3.55 l/s f&r

 

Why would you pull all that to drain the fluid? you can see what you need to with the diff cover off. I only have a 2x4 so I haven't changed fluid on a front diff, but when you remove the cover you should be able to see all of what you need...

 

You don't just remove the cover for the ttb front though, the cover is the axle housing.
You have to like pull the axles and then pull the whole center section from the house, kinda like a 9" rear.

 

Really? damn, that sucks. Oh well, more reason for me to do an SAS.

 

Oh that's for freakin sure, the ttb works for what it is, it's just a pain in the *** when something needs serviced.
Might as well drop the whole front suspension to do any internal work on it.
Take a look under a 4x4 obs sometime and you'll understand.