2006 F150 Possible transmission slipping
Hey guys, I have done some research on this site and read many posts about other owners thinking their transmissions were slipping, only to find out it was a misfire and needed to change the notorious spark plugs issue in these 2004-2008 F-150`s. I am not very mechanically inclined, so give me a break! I will give some basic info and then explain my problem.
2006 F-150 5.4L
6 inch Pro-Comp Lift Kit
35x12.5x18 Toyo Open Country M/Ts w/ XD Monsters
Dual MBRP Exhaust
Stock transmission and gears.
Bone stock everything else.
Mileage: 210,000km = 130,500 miles
So, my issue began with the slipping/tugging feeling when driving my truck, (like the tranny is slipping) always when giving it a little bit of gas but worse when trying to pull hills. This occurs everytime I try to pull a hill without kicking the truck up a gear anywhere from 70km-110km. It will also happen when just giving it light gas on a slight, slight grade. When put into OD Off it seems to run just fine.
I took my truck to my trusted mechanic and after driving he thought spark plugs, I had never changed mine and were long overdue. He went ahead and changed all 8 plugs and coil (all Motorcraft). Incase anyone was wondering, he pre-soaked all plugs overnight, but still managed to break everyone when taking them out (notorious problem). Spark plugs cost $21/each from Ford, and coil was $40. He charged me $60/plug to remove and install new ones. All said and done job cost me about $750.
Got my truck back today and seems to be running a bit better (I also had my 2 front wheel bearings replaced, which makes truck drive alot smoother) but I am still getting this slipping/tugging feeling at the same speeds and under the same stress (light gas and pulling hills without kicking up a gear).
I have not flushed my transmission fluid, dropped the pan or changed the filter yet... could this be the source of my problem? Would my truck symptoms occur from this problem? Seems stupid now, but I probably should've checked this all first, even though my plugs did need replacement.
If not, does anyone have any ideas? I know that with my heavy wheel package and stock gears, along with 210,000km on my truck (only had wheels on it for about 60,000km) it could be the transmission, but I'm really hoping its not. And seeing as it only seems to slip when trying to pull hills and with light gas, it could be something else...
Starting to think that ****in Owner Really Dumb was directed at me lol sorry guys, any help is greatly appreciated. Thanks! Will keep posted on my trucks status.