Hello all!! I've been having this weird intermittent shifting issue. The truck is shifting early all the way up to overdrive, shifts through all of the gears but will go all the way to over drive at roughly 1100-1300 rpms. Once the rpms get caught up the truck runs just fine. Sometimes the truck will also act like its in neutral and then shift out of it really hard. Like I mentioned before, this problem is very intermittent. The majority of the time the truck shifts just fine and it is as strong as can be. The first time I ever had any issues was when I was going down a very wash boarded road. I'm thinking and hoping it's an electrical issue, some sort of loose connection or failed sensor. Thanks for any advice given!!!

 

You need to get the trans codes pulled to know what needs repaired for sure.auto zone will NOT be able to help!

 

^^ X2. Also make double sure the fluid level is correct.

 

I had a similar problem on my '97. I replaced the VSS and fixed my speedometer. It's an "electronic" transmission and the speedometer controls when it shifts. My transmission shifts fine and consistently now but the O/D light is still flashing. Hope it helps. Zoltan

 

yeah that's what mine does exactly all your symptoms and the tranny shop said that the scanner was flashing a speed sensor , so I changed it out but nothing changed it still acts like yours

 

Zoltan,
Please expand on what you had to do to fix your speedometer. Also, what is the VSS? Thanks for the info.

 

VSS is Vehicle Speed Sensor. As for my speedometer I think it was a broken wire but I'll get in touch with my buddy who helped me work on it see if he remembers what it was. Once that was done the truck stopped shifting at high RPMs and didn't downshift on its own without the need for it either. I'll get back to you on the speedometer. Zoltan

 

Ok, spoke with my buddy back home, he is a senior master ford mechanic. He had me pull the VSS and test it. The ohm range on this sensor is 900-2500, at the sensor I was reading 1860+/-, the wires go from the sensor to the abs module, pulled that plug and tested it there, read 1867 ohms. One thing I have not done yet is to have someone move/wiggle the wires around to see if they're going to ground somewhere. Will be doing that tonight. From what my buddy says, there is no reason to troubleshoot the abs module due to the fact that VSS goes right in and back out and to the instrument cluster. Will start the troubleshooting of that is weekend and report back. Just wanted to let you guys know what I've found at this point. Thanks for the input so far, really enjoying being a part of this forum.

 

I've noticed this problem is at its worst in wet weather. Any ideas?

 

Check the wiring between the VSS and the frame rail. It has a tendency to rub on the suspension and chafe the wires.