hunter475

I am having issues getting my 4x4 to engage on my 2003 F150 5.4 unless I am driving at speeds of roughly 10mph or higher. Even then it seems to take a long distance before it locks in. If I engage while sitting still and try slowly rolling forward it will not engage regardless the distance.

Could this be a vacuum leak or something more serious like the fork? The dash lights come on to indicate the 4x4 is engaged and it behaves the same for both 4hi and low. Don't have any issues with disengaging

Just trying to get some input and do a few basic checks before I take it in to the shop.

Thanks guys.

bones2o21

Check the fluid in the transfer case if thats low it will be hard for the 4x4 to lock in.

start simple then look into more complex issues like possible vacume leak

hunter475

Update:

Fluid level is good. The shift motor is working so no vacum issues. I drove around for a while engaging and disengaging the 4x4 to try and get a pattern. After doing this several times I noticed that the 4x4 was engaging like it should. As of now it is engaging as soon as I creep forward unlike before when it would not engage at all unless driving faster.

If this holds true I will have to chalk it up to lack of use. The truck only has 70,000 miles on it and I typically only use the 4x4 a few times a yr. Its mainly a tow vehicle for weekend trips to the lake.

Do you guys engage your 4x4 periodically just to keep the components moving?

bones2o21

my book on my 97 recommends once a month atleast but im always doin somthing that uses my 4x4. also mine is a lever shift not the motor so it maybe diffrent.