The parts houses' VSSs aren't known to be flakey.

Sometimes just cleaning the black, magnetic "soot" off the sensor's face will correct the problem with it.

And, of course, sometimes not.....

Pop

 

From Mark...

Diesel trucks kept the mechanical diode from the start of the 2001 model year until March, 2001.

If you have a mechanical diode when it starts to fail the symptoms are that the trans won't shift 1-2 until high RPM, and then only after you let off the go pedal.[/quote]

Mark, you hit the nail, squarely on the head. This is my problem. So, the big question is, what is the solution? A complete rebuild? I live in the remote mountains of Montana and have little choices for repairs like this. I would have to drive it to one of the bigger towns, like Billings or Bozeman. What are we talking about in the cost to repair this? Tom

 

Yes, it's rebuild or replace time. Low side would be about $2500. High side could get over $4000.

 

Thanks for all of your help, Mark. I too, like so many, am a life long Ford fan. It does disappoint me that these mechanical diodes were used, even on the diesels. It's obvious, that not only high RPM's will mess these up. Seems that these were a problem, since Ford was so fast on changing them out. My 2001 SD was used very lightly. It was only in the past two years that I even put a hitch on the truck and did some trailer hauling, but nothing serious. Needless to say, I'm one of those guys that the economy in the past two years, killed me. Coming up with even $2,500 right now, is out of the question. Unless I can keep driving it without doing even more damage, I will need to park it and call it quits, until a rich relative dies, or something.

 

Mark, again, thanks for all the quick replies. I have bounced all over the forums reading everything I could about these particular transmission problems, especially, with the mechanical diodes. "IF", I have read everything correctly, all or most of the gas versions were corrected before leaving the factory... (although, some claim that they DID discover they had them in their gas truck). And, that for the first three months of 2001, or end of March 2001, the F-250 diesels had them. Correct? I decided to go out and look at the sticker on the door frame to see when mine was manufactured. It says, 06/01. So, should I assume that I DON'T have mechanical diodes and my transmission has other problems? I understand that a complete rebuild is still needed, but I found that interesting that my symptoms are right in line with the mechanical diode problems.

 

Many gas trucks were built with the mechanical diode at the start of the 2001 model year. We were told that all of them had the transmission replaced before leaving the factory. I can believe that a few could have slipped out without getting the trans changed.

Almost. 2001 production started in July, 2000. The diesels (F250-F550) had the mechanical diode until it went out of production in March, 2001. That's nine months of production, not three.

If the truck was built in June, 2001, it should not have a mechanical diode. The sprag one way clutch that was there before and after the mechanical diode could also fail. It's failure rate is MUCH smaller than that of the mechanical diode. But like all things man made failure is a possibility.

 

Thanks for setting me straight, Mark. Wish me luck on what I find out, once I get it to a shop.

 

Did you every get your trans fixed? I have a 2001 7.3L Excursion with the same problem. I had the trans rebuilt and the mechanical diode replaced. Still have the problem shifting from 1 to 2, but can shift manully from D to 2 (same as you). I need to get this thing fixed.