It's been awhile since I read about ASD, but my recollection is that it is basically an open differential with a mechanism to lock if slip is detected, but the locking only occurs at speeds below 15 MPH, so it will not prevent wheel spin exiting a second gear corner hard (at a speed above 15 MPH) like a conventional limited slip diff will. It's probably an asset for snow traction or drag racing, but not autocross or road racing.

A conventional limited slip diff has preload and can be tested by jacking up one side of the rear and determining the amount of torque to break loose the wheel. Be sure to DOUBLE CHOCK the opposite front wheel so you don't drive the car off the jack. Typically you want to see at least 45 lb-ft prelaod using a torque wrench on a lug bolt.

If ASD is basically and open diff rather than a limited slip, it will not have any preload.

ASD requires some sensors and electronics, and I assume part of the control system is external to the diff, so just bolting in an ASD diff without all the system sensors and controls will probably be the same as an open diff.

Duke

That's what others are saying too, Duke. However the FSM shows the preload torque for ASD diffs to be the same spec as LSD diffs (80-160Nm, or about 60-120 lb-ft). That's twice the spec for an open diff (40-90Nm spec). And the 190E-16 LSD has almost identical internal clutches & side gears when comparing the part numbers to the 124 diesel ASD.


Update: That's because ASD does have a normal LSD ring gear carrier!

They are LSD as well as ASD. Stock amount of lock is 15% (some say it's 35%). This is present without the ASD system operative. I have some Bosch sourced documentation for it. ASD Works under 40 km/h and claims to lock up up to 100% (unverified but don't know why it would lie).

They do seem to axle tramp badly even on brand new cars the press mentioned it.

Check this video I made!!!

http://video.google.co.uk/videoplay?docid=-89451780287524338&hl=en-GB

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190E's:
2.5-16v 1990 90,000m Astral Silver
2.0E 8v 1986 107,000m Black 2nd owner
http://www.maylane.demon.co.uk/190esmall.jpghttp://www.maylane.demon.co.uk/190esmall2.jpg