First post for me and I'm looking for some help. I'm not sure "tranny slip" is the best way to describe it but here is what I have.

On Monday, I got in my truck to go to work. I stopped at the first light and when the light changed as I tried to accelerate away, the engine rpm's came up but the truck wouldn't move. The road was a little wet and at first I thought it was spinning. I feathered the throttle and eventually I got it going. It did the same thing at a few intersections but worked normally at other intersections, but once rolling the transmission shifted normally.

The check engine light came on and AutoZone scanned it and got P0755 shift solenoid 2. I went to Ford and bought the shift solenoid and the torque converter clutch solenoid. On Tuesday I dropped the pan and replaced both solenoids, the filter, and added fresh fluid.

After the repair, the truck seemed a little better and the check engine light went off. Well now the light is back on and the truck is just as bad as it was. Once again a scan showed p0755. I've noticed that sometimes while the truck is sitting at a red light, I can feel it lurching forward. Once I get it going, as before, the transmission seems to shift normally. For a while it seemed okay if I manually shifted down to 1 to accelerate away from a light but now that doesn't seem to be helping.

Does anybody have any suggestions? Could it be the plastic bulkhead/circuit board/connector that connects all the solenoids? Maybe a connector on the outside of the tranny? What should I do next?

 

Hello GTAW081,

Have this issue been fixed?

I have a 99 F150 4.2L 4R70W just over 300,000 miles, and the same issue you are having, but no code PO755.

When I am on road everything seems fine, until I take it on the freeway. Once I reach 55 mph and try to go faster, it seems like it do not have the power to gain speed.

So decided to drop the tranny, clean it out, threw in a new torque converter (mid stall), new trans filter and fluid, also replacing the Torque converter clutch solenoid. Hope this solves the issue.

I will let you know in a week.

 

First and only post, and that was 12 years ago. You sure you don't have plugged cats?

 

12 years ago, hope this gives gtaw a spark of life.

That is the next step to check the clogged cats. Is there a specific way to clean those or test if its clogged?

I am in the middle of replacing a TCC since the trans pan is off.

 

Take it to a muffler shop, they have the equipment to test for backpressure and clogged cats.

 

Latest updates:

New (mid-stall) torque converter, Fresh Mercon V trans fluid and filter, New TCC solenoid, new front pump seal.

Took it on the road and freeway, it runs great! was able to get the power and speed after the 55 MPH mark.

Before all of this issue not able to get power / speed after the 50 MPH mark, I remember I added the "Techron - Fuel system cleaner". I wonder if that garbage was causing the issue??

Other than that the truck is running well! next project is the power steering... crap..