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Discussion in 'Commercial Snow Removal' started by slapshotmike24, Jan 22, 2005.

  1. slapshotmike24

    slapshotmike24 Member
    Messages: 36

    HELP HELP! My 1997 dodge ram 2500 wont go into 4x4. I shift the transfer case, but the light isnt coming on and it isnt going into 4x4. Any help quick would be lifesaving!
  2. gcsupraman

    gcsupraman Senior Member
    Messages: 110

    Did you check the fuses - I would start there

  3. slapshotmike24

    slapshotmike24 Member
    Messages: 36

    Im heading out to check the fuses now. Is there anything under the truck i should look for?
  4. sir spaniourd

    sir spaniourd Senior Member
    Messages: 286

    I have an f250 and I had the same problem. aparently was the relay. it was a quick change and it worked. I hope you have enough time to fix that problem.
  5. Nascar Fan

    Nascar Fan Senior Member
    Messages: 167

    4x4 Help

    How long and far have you drivin it? if it's real cold and has not been used frequently it may take a while my 1998 work p/u is that way sometimes it takes forever when it's cold.
  6. slapshotmike24

    slapshotmike24 Member
    Messages: 36

    I checked the fuses, took a quick look at the unit, and nothing! I had it in 4x4 last week for a small storm and it took awhile to kick in then. Should I try heating the unit up with a heat gun maybe??
  7. killed300ex

    killed300ex Senior Member
    Messages: 293

    are u sure its not in 4x4 with the light not on? Because on my dodge the light doesnt come on in 4 wheel drive sometimes. Just making sure u arnt going by just the light
  8. Ian

    Ian Member
    Messages: 96

    Look at your front axle towards the driver side. View from the front of the truck. You will see a large section of the axle tube. It is between the carrier differential housing and the steering knuckle/brake rotor. This large section is a reinforcement for the vacuum shift motor. This vacuum powered shift motor engages and disengages the right front wheel. There should be two wires there also going to a switch. This switch turns on the 4wd light. Make sure the vacuum lines have not come unplugged and that the wires aren't damaged. The shift motor is located just behind the axle tube to prevent damage front sticks and stuff. This is the most likey trouble spot.

  9. Bolts Indus.

    Bolts Indus. PlowSite.com Addict
    Messages: 1,176

    Shift in and out of 4wd a number of times while moving ahead and back. Sometimes they just act up for awhile and then go back to normal. Mine does, and when it does in a storm I leave it in 4wd for the duration.
  10. REAPER

    REAPER 2000 Club Member
    from 60050
    Messages: 2,230

    I read within these threads about this problem. Paid attention as I just bought a 98 2500. It seem's under the truck is a switch activated by a vacume line. Whie pushin it seems a few guy's have had this come off or get pulled loose. I would check that, this has not happened to me. But, I read it here so maybe a search would give you more info. I think you look around the front axel? Like I said it it is within these threads somewhere.
  11. slapshotmike24

    slapshotmike24 Member
    Messages: 36

    I just checked the actual unit and everything is connected! Its not in four, with the snow, its very easy to tell. I am just running out of ideas to fix this thing!
  12. 95RAM

    95RAM Junior Member
    Messages: 1

    vacuum lines

    The vacuum line connect near the transmission also. Mine came off last winter. The vacuum line that goes to the central axle disconnect comes from near the transfer case. Mine was soggy with tranny fluid, so the hose just slid off.
  13. Ian

    Ian Member
    Messages: 96

    Unplug the wires from the front axle disconnect motor. The switch can be unscrewed from the disconnect motor if not to rusty. Reconnect the switch to the wires. Put the transfer lever to 4H. Have someone push in on the end of the switch while it is out of the motor. The light should come on. If it does, the switch and wiring are good to go. Warming up the motor with a heat gun is a good next step. Also the switch motor bolts to the axle housing with four bolts. It shouldn't be to hard to remove. It is a simple vacuum diaphram, rod, three circlips and a shift fork. The ends of the fork should have plastic tabs on them, they help align the collar and provide a wear surface. These tabs wear down quickly and some times just disappear. Make sure the circlips are in place. If you have a vacuum pump, see if the rod and fork will move with vacuum applied.


    If the switch won't unscrew from the motor, with the wires disconnected, jumper the two wires together with another short piece of wire or a paper clip. It does really matter what you use. By connecting them together you create a path to ground for the light. The light should come on.
    Last edited: Jan 22, 2005
  14. plowman777

    plowman777 Senior Member
    Messages: 227

    my 88 dakota used to freeze, the vacuum line gets moisture in it and that gets clogged. .heat it if you can, or keep driving around, it may thaw itself
  15. SkykingHD

    SkykingHD Senior Member
    Messages: 368

    vacuum actuator bad

    That vacuum actuator rusts through and wont move the fork on the inside of axel over the inner and outer axel shafts. The actuator is a dodge only part. I have taken an air hose and forced the actuator to shift in a pinch how ever you will need to replace that actuator.

    How that works is vacuum from engine is routed to the switch on the transfer case. When the transfer case is put into 4wd the vacuum switch reroutes the vacuum from one side of the actuator to the other. In doing this the fork pills the splined coupling over the 2 splined axel shafts.

    Good luck... have had that part fail on a few Dodges...

  16. plowman777

    plowman777 Senior Member
    Messages: 227

    yes i replaced the vacuum "motor"/actuator on my truck, but still had the freezing problems later
  17. SkykingHD

    SkykingHD Senior Member
    Messages: 368

    replaced vacuum motor

    If you replaced the vacuum motor then it can only be 2 things.
    1 a bad transfer case switch
    2 low vacuum due to a leak. Try looking at the steel lines on the cross memeber of the transmission support. There is a good place to have rust cause a leak.

    Good Luck

  18. justme-

    justme- 2000 Club Member
    Messages: 2,138

    OK- the most common problem is the vac actuator for the front axle- they fail from time to time. IF the motor is the problem replacement is the only solution.
    Here's a quick fix for ALL center axle disconnect vehicles so everyone should memorise this.

    Disconnect the vacuum lines from the actuator.
    Unbolt the actuator from the axle housing.
    Notice the actuator shaft has multiple positions and the shift clip (the big u or c shaped thing on the shaft) will be in one of them.
    In the axle housing look at the shift coller- slide it to the "locked" positon.
    Now move the shift clip on the actuator shaft so that is holds the shift collar in the locked position- I believe it is the end groove for Dodges.
    Put the actuator back into the housing making sure the shift clip engages the shift collar on the axle and bolt it back in place.
    Reconnect the vacuum lines.

    you now have the front axle locked- the transfer case will function normally, the 4wd light may or may not stay on- depends on where it's switch is on the axle housing. The vacuum actuator WILL NOT unlock the axle if this is done. I am unaware of any damage that would result IF the actuator begins functioning again after this has been done so do it at your own risk- however this WILL get you 4x4 again in an emergency situation.

    this is a commonly encountered problem and the normally recomended emergency fix.
  19. cdf309

    cdf309 Junior Member
    Messages: 5

    ram emergency fix

    remove the actuater on the front differential , its held on by 4 small bolts, there is a fork attached to the bottom of it, look in the differential hole and youll se a sliding collar, jack up front if needed to , push collar over to lock axle shaft , now reassemble BUT dont put fork back in grooves put in with pressure against fork and you will be lock in 4wd untill taken apart again , garanteed to work and get you threw the storms
  20. slapshotmike24

    slapshotmike24 Member
    Messages: 36

    Thanks for the help guys! I just had to suffer through the drive up and it finally went in to four wheel drive just before I got there! I definetly think I am going to the manual, cable operated system so I dont have to deal with this problem again! I havent taken the truck out of 4x4 yet because I am afraid its not going back in! I guess I've got some work to do this week. Anyway, thanks again for all the help!