99 & up 7.3L Power Stroke Engine and DrivetrainDiscussion of the 99 & up 7.3L Power Stroke diesel engine and drivetrain in the 1999-Up Super Duty trucks and Excursions. No gas engine discussion allowed except on transmissions and drivetrain that pertain to all models. Please confine discussion of topics in this forum to those items that are specific to the 7.3L Power Stroke engine.
2002 four wheel drive quite working (electric not manual)
My four wheel drive was working great then it just quite going into 4x4. I've looked at everything and read my book, checked all fuses and wiring that I can see. I don't hear any motor sounds or clicking or anything that would indicate anything is trying to engage.
Any ideas of what I might do to get this going? Michigan in the Winter is not a great place for 2 wheel drive lately.
Re: 2002 four wheel drive quite working (electric not manual)
Do you have dash lights 4x4 and low range? if they dont come on then your t-case isnt shifting. You can always unbolt the shift motor, manually lock the hubs and shift the t case manually and try and turn the front drive shaft.
2001 F-350 CC ZF-6 DRW 4x4 4.10, 7.5 ton modified J&I flatbed dump, Rifraff frx, Garret BB, Non EBPV pedistal, IH bellowed pipes, DP tuner F-6 chip, SB dual disk, Midwest short shifter, Ranch Hand legend front end, Ford AIS, AGR super pump, AGR gearbox, Mile Marker 10k hydraulic, 4 inch turbo back, Riffraff boots, Pacbrake, 2WD Low mod, ISSPRO boost, pyro, trans gauges, DIY gooseneck/bumper hitches, Prodigy brake controller, 4 leaf overload springs, Viair compressor with horn, Dieselsite 203* t-stat, ESOF lines, DIY Oil HX mod, 08 mirrors, 245/70r19.5 tires
1997 F-250 EC SB ZF-5, Stage 1s, DP F-5 chip, Swamps IDM, 6637 filter, 3in downpipe to 4 in exhaust muffler delete. Leveling kit on ion wheels and 35's, Hid headlights, Reunel Rear bumper, Flatbed w/stackrack
Have you done all the tests that fire57dan suggested?
Following are some things to consider.....( I am not trying to sound like a knowitall, I simply do not know what experience you have at this time to start from..)
There are several areas to troubleshoot. Electrical, vacuum, and mechanical.
You mention that lights do not come on when you turn the key on, or when you flip the switch for 4wd. I would first explore fuses. I would expect at least a couple of fuses are involved in all this circuitry for the dash lights and solenoid, but must admit I have not yet had to really troubleshoot this part of the system on my truck. I do not have a wiring diagram for the truck. Also check the relays.
Major vacuum leaks can cause the vacuum controlled heating and air conditioning modes to not work, as noted in another post. Minor leaks, especially in vacuum lines going to the ESOF hubs which are downstream of the 4wd vacuum control valve may not affect the heating controls, but would kill 4wd hub action. Of course a bad vacuum pump would screw up all these things. But the vacuum pump can be heard if running, or tested to see if it wll work, and if the heating control system appears to work properly the pump must work whether or not there are leaks screwing up the 4wd..
The hubs only control the connection of the wheels to the front axle. If the hubs are dirty and sluggish, they can fail to shift at all or are too slow to respond and exgage/disconnect during the relatively short pulse of vacuum that occurs when you try to shift to/from 4wd. So this is a reminder to clean the hubs several times a year. Note that hub failure does not affect dash indicator lights and that one hub can be working properly and the other sluggish or not responding at all.
Do the hubs work manually? Do the knobs rotate easily, and in fact lock the front axle to the hub? You can test this by engaging the hub into Lock position and manually trying to rotate the axle from underneath the truck. Manually moving the knob back to Auto should free the axle to rotate easily. Again, if the hub knobs do not rotate easily, the hubs are likely dirty internally also and the pulse based ESOF vacuum may not make them work consistenly.
If hubs lock the axle manually but not via dash control, you could easily have a vacuum leak at one or both hubs. Check the lines for splits and cracks, especially near the fitting where a line attaches to the hub. Several members have reported corrosian of the fitting itself. Locate the vacuum contol valve under the hood by tracing the lines and determine whether the electrical operating system is getting juice when activated at the dash.
If the hubs will actually lock the front and you are not really in 4wd, something is wrong at the transfer case. I would expect driving on wet grass, mud, or gravel would be a way to test this for front and rear traction. Never tried it, but putting truck on jacks should enable you to turn a front wheel manually and watch the rear wheel turn also if the system is engaged.
The transfer case is controlled electrically through the dash switch and a solenoid mechanism on the transfer case. In high range it is supposed to connect the front axle to the transmission output so the front axles can actually turn the (supposedly) engaged hubs. In low range it does the former plus it engages gears to compound the drive ratio. Internally it uses a chain, so a broken chain can occur, albeit this would likely break with a major jerk and make some noise so as to be more obvious.
The solenoid mechanism can fail, mechanically or electrically and prevent 4wd from occuring. Have you pulled the electrical plug from the tranfer case and cleaned all the contacts? You could easily just have dirty contacts at this plug. You can also test for electrical continuity to the plug when you rotate the dash switch while you have it loose. After cleaning these contacts do you get lights at the dash? While under truck, have someone turn the dash switch and attempt to engage Low range so you can listen for solenoid action.This mechanism can also be shifted manually to test the system, but again I will deferr to to someone who has done this for details. SInce mine works, I have not tried.
Keep us informed of any findings. We all gain experience from other's experiences.
Lake Norman at Denver NC 1999 250 PSD (built Sept 98) Lariat XLE7 CC Auto LWB 4WD ESOF ABS 3.73LS X-Caliber cap BFG 285E AT/KOs Jayco-TT 31BHS
Thanks, will do the suggested steps, as my body lets me. Have had recent back surgery, and just reinjured my neck. Dork!!!! Have to learn to slow down. Thats what happens when you're 67. Mind works faster than the body.
I have 2 2002 F350s now and the one has ESOF. It was not long after I replaced all of the clutch hydraulics that I found I must have disturbed something. My clutch switch went bad causing the module to think the clutch was not disengaged. What I learned was it has to have clutch signal to shift the transfer case and it must have absolutely no speedo signal to the module to shift also into low range. Bummer was, I changed the module first and it didn't fix it. Ooops. Anyway I just jumped the switch. Works fine now and I have a spare module
2002 F350 SRW crew, long, 4X4, Auto, Edge Attitude Juice tuner, AFE Air, 4" Exhaust, 4" lift, 1 new wheel bearing. (stupid wheel bearings)
02 F350 Dually crew 4X4, zf6, Edge tuner, 4" exhaust, Garrett turbo upgrade, incab adj airbags front and rear.
02 F350 SD, zf6, 4X4, Dp tuner, 5" exhaust, front bags, centerforce dual-friction, Was never washed until 26k, poor thing... in good hands now.
86 F250 XLT lariat 4X4 Super Cab diesel, 4 speed non-turbo,3.5 inch 3 chamber flowmaster, pryo, non-soup bowl, 3" lift, 35" tires, air bags.
85 F350 4X4 Quad cab blueprinted 460 gas, 4" lift and 35s.
85 Chevy K30 diesel, Vulcan wrecker.
05 Dodge 3500 4X4 dually quad cab, Cummins turbo diesel, auto. (my future inheritance, thanks dad)
Case 580 extendahoe.
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