M52A2 tranfer case

[panzerwillie]

I'm getting more understanding of this trucks as i do more things, i fix the air lines located on top of the tranny that conect to the tranfer case to engage the front axle, i notice that shifter its always letting air out of one of the selenoids[rear one] even when in neutral , so i took the selenoids of and look and the shaft that moves back and foward when engaging reverse and first gear when in neutral it applys presure to the ballbearing in the selenoid { rear one }only when fully engage in reverse you get the flat spot on the shaft releasing all the presure of the selenoid which at that time its all coming out od the front one, now i can notice when the truck its off and there is pressure the front drive shaft has preload , also when lever its on reverse, however when there its no air presure the drive shaft has play back and foward , my question the selenoids get air pressure fron the line coming from the frame, if you put a selenoid there and not run air pressure the fron axle will not engage the sprag will that hurt anything can you actually drive it down the road or the friction of the front drive shaft spining will force it to engage, and whats the puspose of the directional engagement, the 5 ton its full time vss the 2.5 tone with there airshift

 

[M543A2]

There is air pressure to the forward drive position hose when the shifter is in neutral or a forward gear. There is pressure to reverse only when the reverse gear is engaged. I would definitely not recommend blocking air pressure to the transmission shift valve. The shifter in the transfer case might then drift into the worng position, like reverse drive when you are going forward. This will result in very damaging drive shaft wind-up. The system is designed to be always shifted in the proper mode so when about 10% slip of the rear wheels relative to the fronts is sensed, the front drive kicks in. You will not gain anything of beneficial value by trying to disable the transfer case shifting, only potentially do damage. The 5 ton system is also used on older deuces like the GMC M135 series and gas M35 series, but there it is mechanically shifted by a special shaft out of the top cover of the transmission linked to the transfer case. The 5 ton and older deuce system was meant to be a no brainer automatic engagement of the front drive. The air shift deuces act like most civilian 4x4 trucks where there is a positive, direct, same ratio front to rear drive engagement. With both systems, 5 ton, older deuce automatic, and air shift deuce, all front drive parts are spinning whether or not drive is engaged. The only way to prevent front drive parts from spinning is with the deuce air shift models, using lock-out hubs.
Regards Marti

 

[panzerwillie]

thanks for the reply ....