Just bought my first f150 and it seems like the tranny is slipping. It happens when the tranny is hot and shifting to fourth gear at higher speeds like accelerating onto the highway. I hear the engine freewheel a bit before taking off again.

It also acts strange if I coast with no throttle. (going over railroad tracks) When I go to accelerate it takes a few seconds to catch. This happens @ 20-30 mph.

History: 44k miles. Looks like the the fluid was recently changed. Smells and looks clean. The truck is equipped with the tow package so it has a little cooler in front of the radiator. I plan to add a much larger one once all this is settled.
Engagement is good in reverse and the fluid level is within the specs on the stick when warm.
Believe the truck has a 4r70 tranny. Says use Mecron V on the stick.

Thanks much. If you need more info I can run out to the driveway and check.

 

They may have put in the wrong fluid it should be mercon V. if unsure on the fluid, change it and add an additive like lube guard.

 

Any ideas what the lubeguard does for the tranny?

If the fluid was wrong wouldn't I have the same problem when it was cold?

 

Wanted to put synthetics in this weekend but would like to have a second opinion before..

Thanks!

 

Only use mercon V in a 4r70w.

 

Hey there Dog.. Was hoping you would drop by..

What do you make of the coasting slip? Is it normal for these trannys or what?

Thanks
Chris

 

No it's not normal. If it did it in reverse too I would think the filter might be plugged or something. Might be a sticking valve or something along those lines. The pump would do it in all gears as well. A line pressure check would probably show the problem. Could be as simple as a bad epc solenoid because the solenoid doesn't really control pressure in reverse. In fact that would be the first part I would look at.Lubeguard is worthless in our tranny's the fluid is already friction modified, and has the agents to prevent the solenoids from sticking.
Alan

 

Thanks for your help dog. If you could suggest where I might be able to find a replacement epc selenoid I'll plan to drop the pan and replace it, and check for stuck valves.

I just read some stuff elsewhere about the selenoid becomming magnetized and attracting particles which cause it to malfunction.

What do you normally use to clean a valve body? Brake parts cleaner and compressed air work ok?

 

Dbl post

 

The ford dealer is the only place you can buy a new epc solenoid(anybody else just buys it from them and resells it) Email me Dirtyd0gus@yahoo.com and I will give you a couple phone numbers of cheaper places.
Clean mineral spirits is the best thing to clean a valvebody with , but brake cleaner will work. Spray it down with some wd-40 as you put it back together.
Alan