re: 4kq CO Tap Tube / diff locking on mine

[jackr@internet.kronos.com]

     Replies to different recent questions:
     
     Yes, my CO tap tube rusted out years ago.  I capped it by removing the 
     bolt the tube comes through and placing a metallic epoxy putty into 
     the bolt and reinstalling.
     
     When my local mechanic put in a new down-pipe for me recently, he 
     removed the CO tube for me.  He never uses them, he says, since they 
     are usually rusted out.  He always taps from the exhaust pipe.
     
     Given someone's recent comment about driveline friction even when 
     going straight, I locked my center diff while coasting toward a red 
     light.  There was no noticable difference in slowing between locked 
     and unlocked in a straight line.  This is with new tires, but I've 
     never noticed anything on old tires either.  I can't feel any 
     driveline stress until I start turning fairly sharply.
     
     My center diff has *never* unlocked (or locked) immediately, even when 
     the car was new.  It will sometimes stay locked a very long time if 
     I'm driving in a straight line.  The lock light usually goes out 
     immediately (or almost so) upon initiating a turn.  I always 
     considered this normal until I read others' different experiences on 
     this list.  I've never had the problem with it remaining locked until 
     I back up.  On the contrary, behavior backing up seems similar to 
     going forward.  I sometimes unlock as I pull into the garage, knowing 
     the snow will be melted the next time I back out, and the diff light 
     is still lit when I start the car later.  It goes out fairly soon 
     after getting in motion, though I'm always looking behind me at that 
     point.  I always assumed it went out as I began to turn, which I can 
     sometimes feel is the case.  I've always assumed all this is normal, 
     but if not, it is also not problematic.
     
     Jack Rich
     90 V8Q
     88 Corvette convertible (not seeing much use lately)
     84 4kq