2nd Gen Ram Tech1994-2001 Rams: This section is for TECHNICAL discussions only, that involve the 1994 through 2001 Rams. For any non-tech discussions, please direct your attention to the "General discussion/NON-tech" sub sections.
My 4X4 vacuum switch motor is bad so I can't engage/disengage my front axle for my 4wd. I can't seem to find a good used one and new ones are ungodly in price. Does someone have an illustration on how to modify this over to a cable type system. I don't want to spend the $150 for an actual "posi-lock" either, and I know many have have used choke/throttle/bike brake cables/etc to make the same system cheaply. If you know how to do this and have the instructions/illustrations on how to do this, PLEASE share with me. I have the housing off right now so truck is parked, and I really need to get it back on the road ASAP.
Thanks in advance!!
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Judging by this diagram, I would have to say that this "motor" is nothing more then a diaphram. I'm sure that if you don't want to spend $$$ to fix it properly, you could dissademble it and make some sort of cable attachment to actuate the shift fork. Actually, now that I've looked at this picture, I may just knock mine off and design my own POSI-LOCK as it doesn't seem to be anything special.
I did take it apart and sprayed the hell out of it with WD-40. It did clean out the rust from moisture it had in it, but is still a little sticky. I did hook the vacuum back up to it while I had the wife shifting the transfer back and forth and it would still catch about 1/2 the time and wouldn't push it far enough to push the 4X4 light switch on. So I figured the easiest fix would be to modify it to a posi-lock. I would love to keep it original, but I'm not going to pay $150 for a used one or $250 for a new one. My gosh, it's just a vacuum deal.
Did you check the local junk yard? The CAD unit is pretty common on Dodge and Jeep 4WD products. I p/u a used CAD off a '93 Jeep Wrangler in my local pick and pull for $15.00. I swapped out the shifter fork off the old one but other than that the unit fit just fine on my '95 Ram 2500. I riggged up a vacuum solenoid with a switch inside the cab so I can control the front axle if I want to use low range in 2WD.
'01 Laramie SLT 1500 4WD