I picked up my 2005 F150 4x4 last winter.

it has 135k miles & a slight tranny problem.

When cruising around 45 mph - right between where it wants to be in top gear or not - if I slightly accelerate the trans BANGS between the two gears.

I mean repeatedly bangs - it is not a smooth shift where it can't decide which gear to use - it is a hard BANG where it can't decide which gear to be in.

What gives? I can usually stop it if I turn on the towning button - shutting off high gear.

 

Whats the fluid look like?. Been serviced recently? I would start there. Im no trans expert but it sounds like maybe your torque converter is giving up on you.

 

Are you at a lower rpm when it happens? Sounds like a coil pack

 

its not a coil pack - its certainly in the trans. It happens when cruising in OD & I slightly accelerate. Really whacks between OD & 3rd.

 

Does it jerk or is there an actual sound? Does it do it at a higher speed or just at low rpm?

 

It makes a bang & I can feel the truck shutter & buck - it stops if I turn off the od with the towing button.

 

hey there I am having a similar problem with my 2007 f150 and I was wondering if you ever found out what the problem was? if it was something with the tranny or coilpacks ect.

 

I have been having the same problem with my 2004 5.4 engine transmission for several years now. If I am traveling in that mph range I just turn off the OD.

 

I bet you have a bad plug or coil. There can't be anything wrong with the trans to make it shift like that. To go from 3rd to 4th the forward clutch releases and the OD band applies. It can't happen fast enough back and forth to give a bucking sensation. You prob have a plug that has carbon tracks on the outside and when conditions are right the spark jumps to ground outside the plug instead of through the plug. Pull each coil and closely inspect inside each boot for the tracking.

 

I had the similar problem and was thinking it was tranny problem ( convertor stutter). Did the trans fluid flush. The problem continued and got worse by the week. Finally replaced all spark plugs with SP515. The problem disappeared since and is running silky smooth now. By the way, the plug change job was done by a local dealer and I was told all spark plugs came out in one piece. Lucky me!

 

Converter shudder really doesn't feel like a buck, it feels more like driving over rumble strips for a second as the torque converter clutch applies. In OPs case the truck had 135k miles when he got it so there is no telling what kind of maintenance was done or not done. Also someone could have washed the engine to make it look pretty and got water past the coil boots.

 

I love when people need help with something but are too much of an expert to listen to anyone.

Good luck

 

I was going to say it was very good advice by 70f100longbed. His advice is always spot on.

 

I have found the search button to be very useful on this forum.

Ford Truck Enthusiasts Forums - Search Results

changing plugs solved my problem, some have required coils too.

 

Thanks for the advice guys. I'll Change the plugs this weekend.

Sounds like everyone knows what's up.

Except for skunk - who was that comment directed at?