Is this an Limited Slip Differential

[Barry.b]

Hi guys
I have searched for an”S” stamped into the casting and I cannot find one.
But if I turn one output shaft by hand , the other one turns in the same direction
I think if it wasn’t a an LSD the other shaft would turn in the opposite direction.
There is / was some paint on the casting which might have been a painted “S” once upon a time.
Can anyone recognize what I have from the photos ??

 

[HB Chris]

Well it is a 3.25 but probably already know that!

 

[Ian C]

Thats what you should see if its lsd.

 

[nosmonkey]

If you pull off the side cover and remove the diff unit the casing should read S25 or S40 on the numbers written on the side of it. Number corresponding to the lock amount

 

[Gransin]

There are also diffs that looks exactly like the one Ian C posted, but have S0 stamped into the case.
These use the LSD case, but it's an open diff (non LSD).
My CSI 3.25 is one of these, and the output flanges turn the same way when one is rotated, but it's not an LSD for sure.

It's a bit difficult, but you can see the stamps on the case if you remove the vent on top and use a flashlight.

 

[Wladek]

Looking at first photo with open vent - shape of inside case is as open diff (non-lsd), numbers stamped lengthwise on inside case says it's open diff (lsd have numbers stamped crosswise (direction of wheels rotation)).

 

[Bert Poliakoff]

Grab a stub axle on each side of the diff. try to turn them in opposite directions I f you can't it's an LSD

 

[Barry.b]

Grab a stub axle on each side of the diff. try to turn them in opposite directions I f you can't it's an LSD

Okay
Unfortunately I can turn them in opposite directions , although there seems to be an initial brief resistance and then they can be turned in opposite directions
So I guess she’s not an LSD after all

 

[Barry.b]

I stripped her down this evening to get it ready for sandblasting.
I think it doesn’t look like an LSD.
But I’m no expert on diffs .
This is only the second one I have ever worked on .
I have new seals for it and I will give it a good clean up and repaint.
Do you guys by any chance know what oil I should put in it when it’s finished ?

 

[HB Chris]

80/90 weight hypoid gear oil.

 

[Barry.b]

80/90 weight hypoid gear oil.

Thanks again Chris

 

[Barry.b]

Thanks again Chris

Hi Chris
Do you know how much oil I should put into the diff ?
Also I am thinking of using Castro LM grease to re pack my rear wheel bearings.
I have new seals for them on order and I am hoping to just regressed the bearings and re use them if they are in good condition.
Does Castrol LM sound good to you ?
Thanks again
And apologies for all the questions

 

[HB Chris]

I don’t know if we have that over here. Buy two liters but you won’t use that much, you fill it til it overflows the filler plug. GL5 is Hypoid oil.

 

[teahead]

LSD: