wisyooper

I recently replaced the 4WD actuator fork on my 2003 5.4l. Truck only has 34,000 miles but the plastic "ears" on the actuator fork were sheared off. See other posts on how to diagnose this problem. Here is the detailed step-by-step process I used:

1. Jack up front of truck and secure with jack-stands
2. Remove passenger side front wheel
3. Remove passenger side sway bar link from lower control arm - this will allow you to remove the passenger side axle housing much easier
4. Remove the 6 bolts retaining the CV joint to the axle end - 12mm 12 point socket needed
5. Remove the plastic splash guard/oil deflector (3 bolts)
6. Remove vent hose from differential and remove vacuum hoses from the actuator motor - secure out of the way
7. Slide rubber boot on the actuator motor toward driver side, remove E-clip on actuator motor, rotate to disengage motor shaft from the pivot arm, wiggle and remove actuator motor. It helps to fully extend the actuator motor shaft when completing this step.
8. Remove the 4 bolts attaching the passenger side axle tube to the differential.
9. Remove the large mounting bolt on the passenger side axle tube.
10. Remove the front mounting bolt on the differential so that it can rotate down slightly. This will help to remove the axle tube.
11. Pull the passenger side axle tube down and away from the differential. I found that moving the CV drive shaft down and toward the front of the vehicle work best. If the stub axle tries to come with the axle tube, just push it back into the differential.
12. You will get a couple of ounces of gear oil drip when you remove the axle tube from the differential. Have a drip pan or rags ready.
13. There is a thrust washer between the stub axle and the axle tube assembly. Don't lose it.
14. Make note of the orientation of the thrust collar (the part that is moved with the actuator fork to engage the 4WD - the tapered end of the collar is toward the driver side - the tapered end is toward the differential).
15. Clean any debris out of the differential cavity - I found the plastic "ears" in several chewed up pieces.
16. The actuator fork is easily removed. Gently drive the pin holding the fork to the pivot arm with a small hammer and pin punch. The pin will come free of the pivot arm, but remain in the fork.
17. Slide out the pivot arm and remove the fork.
18. Replace the O-ring on the pivot arm with the one from the kit. Lubricate the pivot arm and new o-ring with dielectric grease.
19. Slide the new actuator fork ears into the channel on the thrust collar, and slide the whole assembly, including the stub axle, into the differential housing. I lubed the actuator fork ears with fresh gear oil.
20. The new roll pin from the actuator fork kit will have one end that is slightly smaller than the other. Insert the smaller end of the roll pin into the fork, insert the pivot arm back into the differential housing, and rotate the pivot arm until the roll pin aligns both. Once aligned, gently drive the roll pin in until approximately 1/8" remains protruding.
21. Coat the thrust washer with grease (I used dark black gimbal bearing grease that I use on my Mercruiser I/O - you can research the ford spec on this grease but it is only a small amount and I wasn't too worried about the ford spec - the original grease on the thrust washer was dark black). Install the thrust washer onto the shaft protruding from the axle tube.
22. The kit includes a snap ring for the gear assembly in the axle tube - mine looked fine and I didn't replace it.
23. Remove any remaining gasket material from the groove on the axle tube and from the differential case. Replace with Permatex Ultra Black - I researched this and Permatex Ultra Black meets ford's spec for the sealant between the differential housing and the axle tube.
24. Before running a bead of sealant on the axle tube, I practiced putting the axle tube back into position - it is a little tricky. I used a bungee cord to hold the CV axle in a position that provided the most space.
25. Run a bead of the Ultra Black on the axle tube, pull down on the differential, insert the axle tube into the differential, align, and slide the CV axle back into position on the axle tube. Take your time - I did this by myself and because of the practice, I didn't mess up the bead of silicon.
26. Install the four bolts holding the axle tube to the front differential. Hand tighten, wait an hour for the ultra black to slightly cure, then torque to 54 lb.ft.
27. While waiting for the ultra black to partially cure:
28. Install front differential mount bolt. Torque to 66 lb.ft
29. Install the axle tube mount bolt. Torque to 66 lb.ft
30. Install the six bolts holding the axle tube to the CV axle. Torque to 60 lb.ft.
31. Install sway bar link. Torque to 16-21 lb.ft
32. Extend shaft on actuator motor, re-install into mounting hole on the axle tube, re-install rubber boot, rotate, and engage back onto the pivot arm. Install the E-clip to hold the actuator motor.
33. Re-install front diff vent hose and vacuum hoses on the actuator motor.
34. You can test the actuator fork by extending the pivot arm and while slightly rotating the driver's side tire, you can feel the thrust collar engage the passenger side axle.
35. Once the ultra black sealant has cured (24 hours), drain and re-fill front differential gear oil - 75w-90 (about 3.5 pints). This step is optional if you don't want to change the gear oil - make sure and top off the fluid. Drain and fill plug torque is 18 lb.ft.
36. Before re-installing the plastic splash guard/oil deflector, start truck and have someone move the selector from 2wd to 4wd and back to 2wd. Confirm from under truck that actuator motor moves in and out (don't stick your hands up by the fan or the belt). When engaging the 4wd, slightly rotate one tire. You will hear the thrust collar fully engage and the other tire will rotate in the opposite direction.
37. Grab several Busch Lights, sit back, and admire your $500+ plus job that you did for only $30.

wisyooper

I ordered the new actuator fork from RockAuto - best price I could find and shipping was fast.

DORMAN

600560 (600-560)4WD Actuator Fork $24.79

wisyooper

A few pictures.....

Looking into front diff from passenger side showing actuator fork and missing plastic "ears"

The missing plastic "ears" - or what is left of them

Passenger side axle tube and the thrust collar/stub axle. The ears on the actuator fork sit in the grove on the thrust collar.

Jbrew

Very nice! Thanks, I know I'll be looking this one up in the future. Are you going to contribute this to the "How To's" ?

Might want to edit #37...Look here, post # 3515

jprevat

iTrader: (1)

Very nice write up.

Chad Shepherd

I believe I have the same issue.

mbb

how the heck can a 15 yr old truck have 34000 miles LOL. It should have 234,000.

I havent had to replace yet, but the day will come.
Someone made brass ears for theirs I recall , replaced the plastic.

nothing wrong with the fork, just the $0.50 plastic ears

Jbrew

This is true, I recall guys getting their local machine shop to make them up out of brass. 347,000 miles on the 98 and my original plastic parts haven't failed yet (knock on wood). I've already concluded long ago that this truck is strange. Still using the original U-Joints, Alternator and Heater Core as well. This is great, however I have a feeling they will give out at once one day. I lost my AC this year, something I haven't fixed yet.

Anyway, excellent write up/contribution.

Chad Shepherd

So I diagnosed the problem as the actuator fork and replaced it. The old fork was damaged and missing the plastic just as you shown. Took it for a test drive and still experiencing the same issue, loud clanging noise and the front drive shaft is still turning in two wheel drive. Aside from me messing up the actuator fork during installation what else might be wrong.

willsboattail

My03 FX4 front fork chewed up last fall at 62,000 miles. Cost over $600 for Ford Dealer to repair!