hi, can someone tell me from the pic if this diff is lsd or not?
Rescued attachment diff 1.jpeg

Nope

quote:

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Originally posted by clairetoo
Nope

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it's not an LSD

[Edited on 13/7/10 by stevebubs]

Sorry - I should have said `nope it's not' , as said the planetary gears are the giveaway !

Yes it is

Cheers
David

quote:

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Originally posted by clairetoo
Sorry - I should have said `nope it's not' , as said the planetary gears are the giveaway !

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well thats gonna confuse some one its like a pantomime "on no it isn't Oh yes it is"

See here for more infomation, re the differences, you can tell by the raised ribs on the top side of the diff

http://elworth.info/html/differential.html

Cheers
David

That is a sierra viscous LSD

No doubt about it

thanks for the replys. got so confussed with everyone saying a different thing!

Next question, is the rust anything to worry about? and are there any issues with it being a viscous unit?

Dan

the reason for the confusion is, LSDs normally look more like this

where you can't see inside.


not LSD (open diffs) have open sides so you can see the gears inside like this

but as pointed out, the viscous diff is a sort of cross between the two.

the rust might be an issue i'd say. personally i'd take it to a gear box specialist, but maybe a gentle rub with some very fine paper might take the surface off, and it might be alright?

[Edited on 13/7/10 by blakep82]

Simple way to tell is to rotate one input side, if the other side moves the same way it's an LSD.
I can't see the input shaft ends if it is a push fit diff then LSD push fits are so rare, I have never seen one

LSD.

The giveaway on the sierra LSD, which is easily confused as a non-LSD if you're not familiar with them, is that the pin through the spider gears is not central. That whole mechanism is moved over to accommodate the viscous coupling buried behind the crownwheel.

quote:

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Originally posted by snapper
if it is a push fit diff then LSD push fits are so rare, I have never seen one

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If thst's the worst of the rust I wouldn't worry too much. It's likely been sat for a while and the top half of the crown whell will have been exposed to air.

Wipe it clean with a little scotchbright, flush the whole thing out with a little petrol and refill will fresh oil. Run it for a few hundred miles then drain and replace the oil. Any metallic residue will collect on the magnetic pin of the oil filler plug (quite effective in my experience) and can be removed when you replace the oil.