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| | | Joined: Jan 2016 Posts: 4 New Guy | | New Guy Joined: Jan 2016 Posts: 4 | 2 speed will not shift lo to hi or hi to lo. If I switch the vacuum lines one side works, but the other side does not. Is there a valve between the switch and the actuator. My Thinking is one side of the valve working the other not. Already took the actuator apart and everything looks good including diaphram. I have a 1963 Chevy 2 ton that I still haul grain with. The 292 six engine works great when the 2 speed axle works. NOT SO GOOD WITHOUT. To confirm, The 2 speed will shift if I manually change the hi side to the lo side or vice versus. One line works, the other not. Thanks for any help. IF it is a valve, is one available anywhere? | | | | | Joined: Mar 2004 Posts: 6,214 'Bolter | | 'Bolter Joined: Mar 2004 Posts: 6,214 | Welcome to the Stovebolt  Sounds like the Vacuum Switch located near the trans is not working. Could be an internal blockage in the switch or the push/pull cable has pulled out of the switch housing. If a replacement can't be found you could replace the control valve with a suitable electric solinoid valve (12vdc, 3 or 4 way) and put a modern Eaton 2-speed electric switch on the gear shift lever making it electric over vacuum control. Mike B 
Last edited by Mike B; 01/25/2016 8:43 AM.
| | | | | Joined: Feb 2010 Posts: 476 'Bolter | | 'Bolter Joined: Feb 2010 Posts: 476 | The 2 speed diff. on my 46 C.O.E. wouldn't shift with the vacuum switch,but would manually,(it's factory mounted on the dash). And after fighting it for months,I started feeding the switch WD-40 by letting the vacuum pull it in and it started working but leaked and then stopped leaking and has been working great for years! It down shifts smoother than the transmission. | | |
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