truck shifting issues

[corndogggy]

I have an F-150 that isn't shifting right. If it is under torque like accelerating or driving down the highway at interstate speeds it's fine. However, let's say I am in a city, driving around 35-50, and come up on a car. I let off the acceleration, coast, then when the car pulls away I give it a little more gas. In this particular situation it's like my truck can't decide to upshift or downshift or what, so it will buck back and forth. If I let off the gas or give it more gas it's fine, but it does not like moderate speed with a tiny amount of gas especially when coming off of a coast. Otherwise it's shifting fine. I put in a new filter and fluid recently, did not help. Any advice short of a full transmission rebuild is appreciated.

 

[KYBH4Life]

Sounds like torque converter locking and unlocking. Could be the switch that goes to it. On a Chevy, it is connected to the brake pedal.

 

[KYote-Krusher]

Sorry, but if it's an '07 or older, it's the transmission. Specifically, it's the overdrive belt that's shot.

The Ford engineers in all their wisdom, engineered that transmission to go into overdrive at any possible time to make the gas mileage look better but they didn't make that belt tough enough to take it. If you are lucky it will go before the 100,000 mile drivetrain warranty is out and they will fix it for nothing BUT if you aren't lucky, like me, it will go shortly after the warranty is out. Mine went at about 115,000.

Good news .... it will only cost about $1,700.00 to fix it at a transmission repair place or $2,500 if you want to let Ford do it. More good news: If you want to do it yourself, it'll only cost about $500.00 including the new fix for that particular problem. According to a YouTube video it's one of the easiest transmissions to work on.

https://www.youtube.com/watch?v=X6WZE_z9bKQ

HOWEVER, if you have an overdrive lockout on your vehicle, you can just disengage the overdrive, run in third gear around town and may make it for years before the whole thing finally poops out. I've made it for almost 3 years on my 2007. Like you, once I get past about 50 mph on the Interstate, I can unlock the OD and it will stay engaged and get a couple of MPG better mileage. Just don't forget to lock it back out after you slow down.

Good luck.

 

[KY Swamp Beagler]

Sorry, but if it's an '07 or older, it's the transmission. Specifically, it's the overdrive belt that's shot.

The Ford engineers in all their wisdom, engineered that transmission to go into overdrive at any possible time to make the gas mileage look better but they didn't make that belt tough enough to take it. If you are lucky it will go before the 100,000 mile drivetrain warranty is out and they will fix it for nothing BUT if you aren't lucky, like me, it will go shortly after the warranty is out. Mine went at about 115,000.

Good news .... it will only cost about $1,700.00 to fix it at a transmission repair place or $2,500 if you want to let Ford do it. More good news: If you want to do it yourself, it'll only cost about $500.00 including the new fix for that particular problem. According to a YouTube video it's one of the easiest transmissions to work on.

https://www.youtube.com/watch?v=X6WZE_z9bKQ

HOWEVER, if you have an overdrive lockout on your vehicle, you can just disengage the overdrive, run in third gear around town and may make it for years before the whole thing finally poops out. I've made it for almost 3 years on my 2007. Like you, once I get past about 50 mph on the Interstate, I can unlock the OD and it will stay engaged and get a couple of MPG better mileage. Just don't forget to lock it back out after you slow down.

Good luck.

Mine does the same thing. I'm on my second transmission. The first went out at 138k. I might have to try the O/D lockout method because it's really getting annoying. I didn't think of that...

 

[bgkyarcher]

If it's a newer truck, it sounds like the plugs.

 

[12 pointer]

Agreed. Doesn't sound like a tranny issue at all.

 

[bgkyarcher]

Agreed. Doesn't sound like a tranny issue at all.

yeah, sounds like plugs.... just hope it isn't one of the models with the two piece plugs.... costs twice as much, and even more if they break them getting them out....