Have a 97' F150 s/c long bed 4x4, 4.6L auto.
My tranny seems to have a gear between 2nd and 3rd and between 3rd and OD. If I kick it down slightly the rpms jump about 600rpms and it feels like it downshifts, just a little. It happens in 3rd and od. Is this normal? I still have 36k left on my extended warranty. The truck has 47k on it now. When it kicks it to the mystery gear it does gain speed. Any thoughts??????

Darren

 

What you are feeling is the converter unlocking. It is a 4 speed transmission. By the way, never tow a heavy load with the converter unlocked. It will heat things up real quick unlocked and result in premature transmission failure.

------------------
97 4.6 F150, 1/4 = 17.48 @ 82.2 mph, 88 5.0 Mustang 1/8 = 7.409 @ 93.72 mph

 

Larry,
Never tow with the converter unlocked???? How can I lock or unlock the converter? Is it normal what I described in the first post? Will a superchip affect this at all? Thanks
Darren

------------------
97' F150 Lariet s/c long bed 4x4 4.6L auto...no mods yet

 

That means don't tow with your overdrive on. Tends to shift alot, causing your tranny to heat up. As for the superchip it will change your shift points slightly and make them firmer. What it will definetly do is give you more power. My truck has alot more power after shifting into 2nd gear. Before it was a little sluggish after shifting to 2nd. The chip is alot of bang for the buck, check out the computer chip threads to find out more info.

------------------

97 F-150 S/C 4x4 ORP XLT 4.6 tow package
K&N , Flowmaster cat-back w/3" chrome tips. Bosch+4 plugs, Superchip.
Patriot fiberglass toneau cover, Westin chrome step bars.
Future mods: underdrive pulleys,4" lift, 16.5 wheels with 33's,ram air hood,and someday a supercharger.

 

Darren,

What you have described is the normal operation of the transmisison. If you have a 3.08 diffrential your transmission will lock in 3rd at 34 mph and in OD at about 43 mph automatically under light throttle. You don't have to lock it yourself. You know it is locked when you give it light throttle and the rpms do not rise. For example while accelerating your rpms move around and you feel slippage. In this case the converter is unlocked. If you are in OD driving steady with light load with converter locked and you give you engine enough throttle, the converter will unlock without downshifting to 3rd. If you put your throttle on the floor depending on the speed you are traveling, it will go back to 3rd or even a lower gear. This is the way it is suppose to work. If you observe your tachometer you can tell what your transmission is doing with a little practice. When towing, always be sure your transmission is locked or it will build heat as I have said. Depending on what diffrential and load you are towing you might need to tow in 3rd(OD off). I really don't know what effects a Superchip has on the transmission.

[This message has been edited by LarryS (edited 09-06-1999).]

 

Thanks Larry,

I think my rear end is a 3.55 and I think I also havethe factory tow package. I have a tranny cooler and a hitch. I bought the truck used with 47k on it.

 

hey darren I have that same problem and don't buy this idea that it is normal, there is a technical service bulletin out about this the # is SB606399. I have the same problem as you and it is not right, my torque converter unlocks at 80 mph with out trying to accelerate, check with the dealer mine goes in on Wednesday

------------------
99 F-150 sc, 4x4,5.4,wedgewood blue,mods are on the way