Why does my 1998 Ford Windstar GL 3.8l my speedometer doesn't work causing my transmission not to shift why?

(2010-05-30 12:05:47)

1. Gueracaliente Says: mostly when I just start it or hasn't been running very long, but once its wormed up speedometer kicks on and it shifts just fine.

2. carbidetooth Says: Most likely a Vehicle Speed Sensor (VSS). VSS generates the speedometer signal and also provides info to the Transmission Control Module (TCM). The TCM is what controls shifting. A malfunctioning VSS could affect both things you mention.

3. Theo Says: Sounds like you have a speedometer cable going out. You can just lube it with something like Napa Chain and Cable lube by pulling it out and wiping it off then spray the crap out of it. (the speedo cable can be a pain in the uno but it just usually connects on the backside of your gauge cluster. Your best bet is to just replace it. It's not shifting because your computer is getting a false reading as far as how fast your going.

4. Morphew Says: Here is a little incite on your Windstar. The 3.8 motor that was standard in the LX models early in production and then eventually standard for the GL models later in production are actually Ford Taurus motors as with the transmissions. How is the relevant to your question? Well the Windstar regardless of model or year has an extra 1,000 pounds plus to its weight. With this extra weight being put on a motor and transmission built for a sedan causes the 3rd gear ratio to go bad. In your case I can almost guarantee that the way it acts you think that 1st or 2nd are failing. However 3rd is really your issue. To replace a transmission on these vehicles is not cheap. Your best route is either a rebuilt transmission (with rebuilt or new torque converter) that can handle the extra weight or purchase a new transmission with the torque converter being able to handle the weight.

Your speedometer is freaking out because of the VSS sensor needing replaced. It corrodes and can actually catch fire if not repaired.

The quick and free fix to your transmission issue and anyone having this or another transmission issue with this vehicle is to let the transmission fluid drop to a middle level enough to where you will not ruin anymore gears. Doesn't take long because the fluid is burning up because of that 3rd gear ratio I was telling you about. Advance Auto, Auto Zone or NAPA has Bars Leak Transmission Stop Leak. Your transmission isn't leaking but the thickness of Bars will coat your transmission thicker and cause it to slip and act A LOT better.

When you start the vehicle after reverse or just starting out moving forward DO NOT PUT THE CAR IN DRIVE! This only makes the transmission more fragile when the bands hit 3rd gear and the transmission can drop to the road causing you to go the opposite way the transmission did.

Instead put it in second gear. This activates the transmission fail safe mode for ALL Windstars. Don't punch the gas like you are in a hurry because you'll be back where you started as if you put it in drive. Around 2,500 RPM or 30-40 MPH let off the gas and shift in to drive. When you feel it kick back into 2nd gear (RPM goes up slightly and you can feel it) let off the gas a second time and then gradually speed up and this will put you in to 3rd and right after 4th and you'll be fine.

Since this happened to me I noticed that the transmission failing and driving it this way actually increased my MPG to 25-30 and get between 400-450 miles to a fuel tank and I drive a 1995. Take that Prius owners!