Hello,

Well I figured I'd post this because it has happened to me quite a bit and I've finally can fix it without replacing or buying anything.

I had an 2006 F150 Lariat 4x4 (Traded it for a Raptor Supercrew 6.2L)

Problem - 4 Wheel drive auto engages when turning at low speeds, (Parking) or 4WD grinds when going over humps or bumps. This usually happens after someone replaces your front tires, front shocks and front half-shaft.

Fix - I have 2 situations where.
1st - 4 Wheel Drive auto engaging. After having this problem over time and getting worse over time the quick fix is to put it on 4x4 HI for 20 sec, then shifting this back to 2WD. This will get you back to normal. Long Term Fix is to have the dealer or your mechanic, bleed the air/water out of the 4WD lines. This will fix the auto engaging, of course until you get more air and water int the lines. There is good youtube video that shows how Ford's 4WD system work and how it shifts in 4 Wheel drive

2nd - An Auto Repair shop who will remain nameless but Im sure y'all can guess. The promise to do everything for less. Now I know why.

I took my truck to get my shocks and front half-shaft replaced and when I drove the truck it would lock the 4WD system everytime I would go over a bump. You could feel it on the freeway more. It would give you the sensation of the tires hitting the FW but it was really the 4WD system trying to lock.
Fix - Took it to the dealer, the took everything apart and put everything back (Specific Process) therefore bleeding once again the lines and viola! Issue resolved!


Hope this post helps.



Coronabeer

 

So were the IWE's locking in and giving a light on the dash that it was in 4wd?

I just replaced my struts, and tires about 2 months ago...front end seems very noisy while driving, and it feels like something is dragging while driving. I was blaming the tires (New BFG Rugged Terrains LT275/65/18), and the Rancho Quick Lift Loaded's. But my gas mileage has dropped by about 1-2 mpg's...I also had to have a axle installed on rt. side due to a torn CV boot...

The dragging feeling is intermittent. Sometimes it drags, and sometimes it feels great...the dragging has been going on for a long time...truck has always gotten crappy mpg's but I'm in the 9mpg neighborhood now...

 

Make sure it's not the brakes that are dragging.

 

Jacked up front end yesterday...

Right side is locked in as suspected. It is getting good vacuum (21") at the hub...

Gonna take it in on Monday...not sure if it is a result of the replacement axle, or it was its time to go...the shop that replaced the axle is also questioning that...

Left side is fine...

Regards!