My 1995 4.0 V6, 4X4, the OD switch just started blinking on the dash without any warning. The engine and transmission was running fine. The lite just came on, and I noticed the RPM is running high when shifting into 2nd gear. If I accelerate and then take my foot off the gas, it's shifts easily into 2nd gear. All the other gears are fine. This hard shifting into 2nd gear, just started after the OD switch started blinking on the dash without warning. I bought an OBD1 code reader and found the following codes: Engine OFF, Ignition ON: Code 646 - Incorrect Gear Ratio obtaind for 2nd Gear - Second Gear failure. Engine Running : Code 632 - O/D Cancel switch, Overdrive cancel switch did not change state during KOER.
I disconnect the battery for 2 minutes and then reconnect it and the OD blinking light went out. I drove the car and it shifted fine in all the gears even 2nd, however, about 30 minutes into the driving I went up a steep hill and turned to go down another hill and the OD started blinking ( about 25-30 MPH). I disconnected the battery again and manually turn of the OD using the OD/switch on the Gear shift and the transmisson shifts fine. Question: 1) Why is the OD switch keep comming on 2) What do I need to do to correct these two codes listed above
3) Should I put a new transmission in? I call a Ford dealer and explained the problem, and without even looking at the truck, the Svc Writer advise, whenever the OD switch starts blinking, it's a serious transmisson problem, which would require them to GO INTO THE TRANSMISSION. I was quoted a price for a "fix" - new transmison - $2500.00 -$3000.00. Note: Before the OD started blinking, the transmisson was running FINE.4) How bad is it to drive with the OD switch manually turned OFF below 40 MPH and then manually turning it on over 40 MPH, using the gear shift OD/ button? If there is a 2nd gear issue, the OD would still kick in over 40 MPH?
Any help appreciated. Thanks in advance for your assistance." (You may always add more later