MUDRUNNER Posted January 4, 2012 Report Share Posted January 4, 2012 Alright, got a 2003 F 150 FX4. I've had it for about 6 months now. The 4WD worked just fine the last few times I needed it...till last weekend. Luckily I was able to finagle around enough to get out of the slop I was in. The transfer case is working and engaging properly. The vaccum acuator on the front differential is working. it engages when the 4WD knob is turned, and disengages when you go back to 2WD. ( Had the wife turn the knob while I watched it.) However, the differential does not engage the CV axles. After a little research it seems Ford has had a problem with the little cogs on a shift fork that engages the axles on the front differential wearing out. Instaed of engaging it just slops around. Does that sound right? I'm going to tear into it Friday, just wandering if anyone else has had this problem, and how hard the fix is. Quote Link to comment Share on other sites More sharing options...
LETMGROW Posted January 5, 2012 Report Share Posted January 5, 2012 The first thing I would check is to be sure you are getting full vacuum to the vacum motor ( diaphram ) Ford has a vacuum harness available to correct a low vac, problem due to moisture- corrosion buildup in the lines. Recheck the linkage going into the axle housing. These are prone to rust and corrosion build up which will not let the linkage go full stroke. The gears will partially engage but not all the way. I haven't seen gear problems but can't say for sure they don't exist. We have several Fords owned by fleet customers which have had linkage problems. Usually soaking with a penetrating oil and working the link by hand will correct this. You could engage the 4-WD and try to help the linkage along to verify if this is the problem. Lynn Quote Link to comment Share on other sites More sharing options...
MUDRUNNER Posted January 9, 2012 Author Report Share Posted January 9, 2012 Thanks for the tips Lynn. I got her all fixed up over the weekend. I pulled the front differential out and removed the passenger axle tube. Sure enough, the plastic tips on the ends of the shift fork that engages the front axles were broke off, and the knobs that hold them on were completely worn down. Unfortunately you can't buy just the shift fork ( which looks about like a $10 part), you have to buy a whole kit, and it's a dealer only item. About 5 hours and $230 later I'm back in business. The whole fork design looks pretty chinsy, so we'll see how she holds up to regular use. Quote Link to comment Share on other sites More sharing options...
LETMGROW Posted January 9, 2012 Report Share Posted January 9, 2012 Look at it this way if it makes you feel any better. 9 years old, you don't know all the history. I think you did OK. Lynn Quote Link to comment Share on other sites More sharing options...
Shaun_300 Posted January 10, 2012 Report Share Posted January 10, 2012 Glad you got it fixed up! Thanks for helping Lynn, not familiar with the Ford setups. Nice to have a tech on board that works on all makes! I know the Chevy Trailblazer front diffs have had problems with the shift forks breaking. Surprisingly GM actually sells it separately. Quote Link to comment Share on other sites More sharing options...
LETMGROW Posted January 10, 2012 Report Share Posted January 10, 2012 I'd still look at the vacuum hose. Perhaps the engagement is a little slow due to low vacuum and the gears are fighting the fork. I'm not absolutely sure if this applies to 2003 models but a call to your dealer's parts dept. might help you. Lynn Quote Link to comment Share on other sites More sharing options...
MUDRUNNER Posted January 10, 2012 Author Report Share Posted January 10, 2012 Yea, i checked the vaccum hoses and selenoids on the firewall, and gave the actuator a good soakin while i was at it. Seems to be working smoothly now. I think eventually I'm going to get rid of the vaccum actuator completely and install one of those Posi lok cable actuators. I use my 4WD pretty regularly, and it makes me a little nervous having everything controlled be vaccum actuators and selenoids. I miss the good old days with the lever on the floor and lock out hubs LOL. Quote Link to comment Share on other sites More sharing options...
LETMGROW Posted January 10, 2012 Report Share Posted January 10, 2012 Just be glad you don't have a later model with the vacuum hubs. Those are a nightmare in themselves. LYNN Quote Link to comment Share on other sites More sharing options...
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