Finally went on a 1000 mile road trip with the 2009 F-150. It goes down the road nice except for the trans going in and out of lockup everytime I come to a little hill. I had the cruise set at about 85 and the slightest incline would kick the trans down a gear, or out of lock up, and the rpm's increase. It would kick back into lockup once I was on level ground. It was smooth doing this so it wasn't that annoying. Just wondering if any of the trans chips or programming would get rid of this. Any information is greatly appreciated.

 

This behavior can be modified a bit by a programmer, but the fault seems to be in Ford's idea of "torque control". It's possible you were really only experiencing TC unlock/lock, but you do have six forward gears, right? This "twitchy" transmission has been a pet peeve of mine too, on my 2005. I've been able to adjust the TC unlock/lock points to minimize this to where the change feels like it's more in tune with the demand, using my Gryphon programmer.

Still, cruising at 85 may have contributed to this behavior. Would it do the same thing at 75? The effect of wind resistance is squared with an increase in speed, so any doubling the speed causes four times the amount of wind resistance - which is significant at that speed. And, your road friction is increased too. So, you've put a significantly higher load on the truck at 85 vs 75. It just may be that it's sort of operating at the "breakpoint".

- Jack

 

Thanks for the reply Jack,

I do still have 6 speeds forward. It still does it at 75, but I can control it better if I do not use the cruise control and hold the throttle steady. But, on a long trip, it is nice to use the cruise.
I had a 97 w/ the 5.4 but it had 3.55 gears. I wish I had the 3.73 in that truck like I have in the new one. I will get with the Gryphon people and see if they have any more info. But I do thank you for the reply.

Phil

 

I tend to think the fault is in Ford's cruise control. It's too responsive on hills. There is no need to accelerate that hard to maintain speed or to increase speed. I agree he is experiencing TC unlock/lock, and with cruise control off he would climb those hills without the TC unlocking. It would be nice if Ford offered an economy setting/switch on the cruise control which would tame it down for better fuel economy and smoother acceleration.

From my experience the increased RPMs (over 2k) provide more torque which helps keep the TC locked. I drive a lot at 35-40 and the TC is seldom locked at that speed and low RPM.

 

Yup. Looks to me like the speed decreases about 2 mph, then the cruise control kicks in and tries to "catch up". But to do so, it has to increase the throttle to the point where the TC unlocks. Then, there's an "overrun" at the top of the hill, where the speed increases about 2mph or more before the throttle backs off. Sort of irritating.

As I said, I've tamed this down quite a bit with the TC lock/unlock adjustments we have on the Gryphon and possibly Bill has modified something in the shift strategy too, to help.

I still get the same behavior though if I'm pulling a trailer. I honestly think the engine has enough reserve power to pull it through these little ups and downs without changing the gearing - I could certainly do in in a stick shift - but, this is what happens when you give control over to an electronic device.

- Jack