WRX LSD's?

[stiwagon]

Hey, Im new to Subarus so this may be a dumb question but here goes anyway.

I have 2 LSD diffs out of GC8 WRX's but they are both different internally. Im guessing that 1 may be a plate type and the other a viscous or similar. Anyway Im not sure how to tell one from the other so can anybody identify them from the pictures?

Thanks

[kamineko]

with the plated diffs you can see the clutch pack through the holes. therefore (2) is likely a sealed viscous unit, the clutchpack is buried inside and the spider gears mate to that

not sure on (1) , havn't seen that before, any holes in the case we can look into?

[kamineko]

ok scratch that, these look very similar to (2) and appear to be a plate diff

so disregard me i'm confused

(my understanding was the exposed clutch pack and 'donut gear' you can see below can be replaced by a 1 piece sealed viscous unit)

[Lynx]

First one seems like a AP Suretrac, had one on my V6 STi. Think WRXONP knew abit about them?

[stiwagon]

 kamineko said:

not sure on (1) , havn't seen that before, any holes in the case we can look into?

There are no holes, just a solid unit. Its unlike anything Iv seen before with Evos.

[kamineko]

 kamineko said:

ok scratch that, these look very similar to (2) and appear to be a plate diff

so disregard me i'm confused

(my understanding was the exposed clutch pack and 'donut gear' you can see below can be replaced by a 1 piece sealed viscous unit)

ok put some more thought into this haha

i think its still a viscous unit. there is no pressure being exerted on the plates, other than the preload. the differential speed causes friction between the alternating plates and the viscosity of the lubricant changes with heat - forcing them to progressively bind.

i believe i have become confused with the 'sealed' viscous unit used in a newer centre diff

so.. (2) viscous LSD

x way mechanical plate LSD operate in a similar fashion, except mechanical force is exerted from the cam of the spider gears axel.. see this much better writeup with good pics

http://www.motoiq.com/magazine_articles/id/1322/pageid/1493/project-nsx-part-2-tuning-a-limited-slip-differential.aspx

(1) likely this? http://forums.nasioc.com/forums/showthread.php?t=1694033

looks like newage subaru mechanical LSD

[WRXONP]

Yip top one is defiantly a ap suretrac mechanical LSD - no plates - theoretically the design cannot wear out - I had one in my v3 - it was super tight - ill try find the site I got all the info about them and post it

[WRXONP]

Quoted from here http://new.minimania.com/nmm/GEARBOX___Limited_Slip_Diffs__what_s_available__839.htm

 

AP Racing. AP’s ‘Suretrac’ LSD is a relatively recent addition, mainly targeting the road user. The design uses cams and pawls. Consequently, despite AP’s claims that it’s a ‘novel’ and ‘unique’ concept, the design and ‘modus operandi’ is acutely similar to the established Jack Knight pawl-type, just a little more refined. The cams have a series of ‘lumps’ on them (1). The pawls have ‘lobes’ on each end (2), and are positioned horizontally between the cams, carried by fluted internal and external drums (3). When running in a straight line, no movement of the pawls takes place as there’s even traction on both wheels. Once a difference in traction occurs, the pawls slide in the flutes, engaging the cams. The amount of slip allowed is controlled by the frictional force developed between the drum flutes, pawl lobes and cam lumps, the resultant torque bias being applied to the axle with most traction. Pro’s - very ‘gentle’ in operation. Con’s - Comes as a sealed unit with ‘factory’ devised settings, so isn’t user tunable or serviceable. Won’t work with one wheel off ground - result, no drive. Usage - Road, drag racing, circuit racing with well-developed chassis (absolute minimal body roll, and stay off the kerbs), anywhere that won’t experience air-born wheels. Bill says - “Never seen one, but theory says similar experience to Jack Knight diff”. Cost around £485.00 plus VAT.

[WRXONP]

The easiest way to tell a suretrac LSD is the mig welds on the LSD unit - u can see the heat from the welds on the top pic

[WRXONP]

Are u deciding which diff to use in your car ?

[slydog]

think they are on trade me now!

[stiwagon]

 WRXONP said:

Are u deciding which diff to use in your car ?

No, I am selling them. I own a auto part company called Dansco Auto, but have never dealt with Subarus before so didnt know how to tell what they where. Thanks for your help identifying them! And they are on trademe if anybody wants them

http://www.trademe.co.nz/Members/Listings.aspx?member=3813197

If anybody wants anything WRX or anything listed on trademe, contact me through here. Ill do ClubSub members good deals!

[Timmah]

 stiwagon']

[quote name='WRXONP said:

Are u deciding which diff to use in your car ?

/quote]

No, I am selling them. I own a auto part company called Dansco Auto, but have never dealt with Subarus before so didnt know how to tell what they where. Thanks for your help identifying them! And they are on trademe if anybody wants them

http://www.trademe.co.nz/Members/Listings.aspx?member=3813197

If anybody wants anything WRX or anything listed on trademe, contact me through here. Ill do ClubSub members good deals!

Damn it, wish I had the money for a lot of parts you've got listed

[driftrex]

 Timmah']

[quote name='WRXONP said:

Are u deciding which diff to use in your car ?

/quote]

No, I am selling them. I own a auto part company called Dansco Auto, but have never dealt with Subarus before so didnt know how to tell what they where. Thanks for your help identifying them! And they are on trademe if anybody wants them

http://www.trademe.co.nz/Members/Listings.aspx?member=3813197

If anybody wants anything WRX or anything listed on trademe, contact me through here. Ill do ClubSub members good deals!

Damn it, wish I had the money for a lot of parts you've got listed

yea me too :'(