In response to "You can't really test the LSD like that, IIRC. With both wheels in the air and the car off it'll act just like an open diff. My understanding is that on a clutch-type LSD, the LSD functionality only works when there's power coming in from via driveshaft.", Ken wrote "Yes, confirmed. Two days ago, I installed the Alfa Q2 LSD unit. No apparent difference when rotating one axle shaft, the other axle rotates the opposite direction."
Ken, compliments on getting your Q2 unit installed. You must have a FWD Alfa, is it a 164? Did you take the whole transmission out or just remove the differential cover? How do you like it? As an aside, I think you need to be careful about making analogies between different types of LSD in terms of how you can determine their presence. The Q2 unit is a worm-gear based Torsen differential, designed without preload. The one used on RWD Alfas is a traditional clutch-based one. The two types may not behave identically when tested by turning the wheels on a lifted vehicle. In addition, I think it matters whether the transmission is engaged or in neutral during testing. Did you test in neutral or in gear? On a car with an open differential, if both driven wheels are in the air, I believe it is possible to grab one wheel and stop it while the engine is idling. And somehow I think I saw somewhere (a factory shop manual for another brand, IIRC) that to test an LSD for wear one could mount a torque wrench on a wheel bolt with both wheels in the air and measure the amount of torque transferred. But don't take my word for it. You might get hurt or cause material damage if the method doesn't work. Maybe it works better on viscous coupling type differentials. Regards, Sonny '91 164 S (with Lancia Viscodrive LSD) -- to be removed from alfa, see http://www.digest.net/bin/digest-subs.cgi or email "unsubscribe alfa" to [email protected]
