It sounds like you probably have the same version I do on my 79
CJ7 . I have the
AMC 304 ,
GM Turbo 400 mated to a
QuadraTrac fulltime 4wd
Transfer Case .
I just had my
GM Turbo 400 thoroughly rebuilt about 6 months ago. Right beforehand it was slipping HORRIBLY, requiring me to run up the RPM's to get it to partially
slide into gear. It whined at that point--- basically the point of death for my tranny... But it was NOT at a given mph, just whining like heck as it slipped badly...
Your T case requires special fluid unless it has undergone the "milemarker" conversion to a 2x4 from full time 4wd. I would check to see if it is full. There are several plugs on this TC. You need to get the shop manual and determine which is the drain plug and which is the "fill-to" plug. If you have the optional reduction unit on the TC, it also has fill plugs. Too low fluid could cause a whine, and ultimately a "bang-bang" sound as the worn out chain slips on the large gears.
I'd also try and rule out worn out U-joints on your driveshaft. They can cause a whine, especially at a given mph.
Does it whine the same at 45 mph whether you are in "drive" (presumably in 3rd gear at that speed) or if you pull it down into 2nd gear?
Try and rule out every variable you can.
good luck
brian
