I have a ford f150 fx4 with 45,000 miles on it. I noticed when i am driving uphill at approx 40-50 mph my truck begans to jerk. I was wondering if it is my transmission slipping or I just need to change my transmission fluid ( which I have not done yet). Would anyone recommend "Royal purpal" tranny fluid???

 

Its not jerking it sounds like it is "hunting" for gears in which case you should turn the OD off.

 

Knowing the year of the truck would be very helpful. If it's an '08 or older, it's pretty close to the time for a transmission service / flush / change, pick your poison. If it's and '09 or newer, it's possibly hunting for gears.

 

According to his profile, he has a 2007.

 

My overdrive is off, actually I never use it too much. It does feel like its searching for gears, but its already in 4 th gear. It feels like it going between 3 rd and 4 th gear. Why is that???? Is it my tranny fluid? I haven't changed it yet.

Thanks.

 

If you are driving up hill, the trans. going between 3rd and 4th would be common, especially if the grade is a bit steep.

 

This is the wrong thread for an 07, but be sure to get a stress test done on your coils... I had one that would intermittently miss under load (like going uphill) and it felt like the trans was slipping. One mechanic tried to sell me a new trans... Then I got the stress test done and replaced one $50 coil. No problems since.

 

Thread moved.

 

Plug, coil or coil boot. Misfire under heavy, low rpm loads.

 

Well its not under a heavy load , actually no load. When its in 4th gear its a small jerking feeling. But now that I think of it I don't think its going between gears. At first I thought I had a flat.

 

Flush the tranny and change the filter you are at the point that it should be done. I usually do mine every 40k which is a bit shy of what is recommended but helps to prolong the life.

Also OD should only be turned off when under a load or on steep inclines. You should be using it the rest of the time. This may help other parts of your truck run better to if you leave it on for a bit.