My 1991 F150 has been shifting hard as of late in all gears, as well occasionally slipping out of gear when cruising around 35-40 MPH, and it would take shifting to neutral or down to second and back to drive to get it to grab again. I haven't had time to deal with it for a few weeks.
But the other day at school I got on the computer and looked up TSB's for the E40D. I didn't write down the number (sorry) but basically it was advising that there was a concern that water could get into the MLPS connector and cause issues like hard and erratic shifting.
So last night I got under my truck and pulled the connector off. I didn't see any obvious signs of corrosion/contamination, but but hit the connector and MLPS with some electronic cleaner, smeared some dielectric grease on it, and put it back together.
So far it's been shifting smoothly and running great!
Just thought I'd share that with you, since I know a lot of people have issues with E40D's and this was a very quick and simple fix.
Thanks for the post. When I had issues with my E4OD, I loved to see helpful posts like this. There's so many things that can go wrong with fully electronic controlled transmissions. My shifting issues turned out to be issues with the PSOM behind the dash.
Glad to hear you resolved your issues with something so simple.
About a week after I posted this, my truck started shifting hard and slipping again. Some days it was more temperamental than others, but it would almost always be non-existent in the morning and then ever-present in the afternoon.
I finally got around to testing my MLPS a couple weeks ago and found the ohm values to be far out of range compared to what I was supposed to have. Aftermarket replacements were around $80 so I hit up the local pick'n'pull and found one for about $8. Before installation, I checked the ohm values with a little guess work on sensor position and they were good enough that I gave installing it a shot. It took 10 minutes, and that's only because I cleaned the mounting bolts and spread di-electric grease on the connector.
No problems since replacing the MLPS. It's shifted smooth and stayed in gear every day since then.