4x4 issue with a 98 Expy
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5th Wheeling
Joined: Jun 2007
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4x4 issue with a 98 Expy
I posted this question on The Expedition Forum and got only one response and the issue still reamians....last weekend on the beach I lost 4 wheel drive...the only thing that was light was the A4WD light in the dash panel...but it surely wasn't engaged....It was suggested to replace the transfer case shift motor....after inspection i could see that after 10-12 years on the beach it showed major rust and almost completly eaten through the case....So i replaced it yesterday with a new unit....stll the same issue....when i turn the selector the A4WD light comes on...but no engagement...turn the selector to 4WD....nothing....to 4WL...nothing.....after this i hooked the origional motor directly to the battery and saw it did engage properly....so i am left with a new motor installed and still no 4 wheel drive.....any suggestions would be greatly appreciated.....Thanks....Jim 1998 Expy
Post Fiend
Joined: Jan 2005
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My guess would be that your front hubs are not locking. Select 4WD, lift one front wheel clear of the ground and then rotate the wheel. If the wheel will not rotate then the 4x4 is working. If the wheel does rotate then look under and see if the front driveshaft is turning with the wheel, if it is then the transfer case is not engaging. If the driveshaft does not turn then look to see if the axle shaft on that side is turning. If not then the hub is not locked.
I assume your hubs are locked by vacuum so check all the vacuum pipes to the hubs.
I assume your hubs are locked by vacuum so check all the vacuum pipes to the hubs.
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5th Wheeling
Joined: Jun 2007
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This is what I discovered after your suggestions Lazy K....with the vehicle running....I turn the selector switch to A4WD...the light apppears on in the dash....I raised the front of the SUV....both wheels spin free....both axles turn freely.....drice shaft spins freely.....no matter which position I turn the selector switch in the dash to A4WD...4H.....4L....The A4WD light stays on....with the same results at the wheels...axles...drive shaft....all turning very freely...This is a 1989 Expedition in which I just replaced the transfer case drive motor as suggested by someone else on this site...Any help would be greatly apprecitated....Thanks...Jim
Post Fiend
Joined: Jan 2005
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here`s the problem with your test, I assume A4wd is automatic 4wd. This means that the transfer case will not engage unless rear wheel slip is detected. You need to have the selector in either 4wdhi or 4wdlo for the test. The front driveshaft should not turn when the wheels are rotated.
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5th Wheeling
Joined: Jun 2007
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Thanks Lazy K....I did the test as you suggested with the switch in every poosition A4WD...4H...4L.....all had the same results......free spinning wheels on both sides....free spinning axles on both side....drive shaft turning with the wheels and axles.....This story only deepens...after all these tests....I decided to go through every fuse under the hood and under the dash....one by one I took out to inspect...found no blown fuses......but afterwards as I turned the selector switch To A4WD...it engaged at the front wheels....as I turned the selector switch to 4H....it engaged front wheels locked in....same with 4L....front wheels locked into drive mode.....I tried this numerous times with the front wheels off the ground and while driving over the course of yesterday with the same results....the 4 wheel drive seems to be working perfectly now?????? this seems very odd to me...just waiting for it a fail again....
Post Fiend
Joined: Jan 2005
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Excellent. The fact that the driveshaft was able to turn showed that the transfer case was not being shifted into 4wd. The most likely cause was that the shift motor was not energizing. You probably found a fuse that was not making contact properly and removing and replacing it "cleaned" the contacts.
Look your owners manual for the location of the transfer case shift motor fuse (might be called the transfer case actuator) and if it happens again, use some electrical contact cleaner on the fuse.
If you don`t have an owners manual go to fleet.ford.com for a free download.
Look your owners manual for the location of the transfer case shift motor fuse (might be called the transfer case actuator) and if it happens again, use some electrical contact cleaner on the fuse.
If you don`t have an owners manual go to fleet.ford.com for a free download.
