I've been called upon for some transmission advice, but don't know much about diagnosing automatic transmissions...so I call up those who may know.


The vehicle is a '91 Ford Ranger with 130k miles. It was in a 5-10mph fender bender the other day. Cosmetically, the bumper got smushed in, but that's all. I drove the truck to help diagnose what seems to be something else that got knocked loose. From a stop, under normal acceleration, the tachometer works just fine, but the speedometer fluctuates up to about 30mph before it stabilizes. From 0-15mph it does not register any speed. It is hard to tell what gear the truck is in when starting from a stop (1-2 or 2-3). When in that 'mystery' range of 0-30mph, however, the transmission will make a good clunk in between gears.

They also noted the ABS light has come on since the fender bender.

Could the transmission issue be as simple as a loose speed sensor or cable? (i dont know what they have)
Could the ABS be as simple as a loose electrical connection? (once again, not familiar with abs other than it has a gizmo and some wire by the brake )

 

according to Ford Ranger Speedometers - How They Work the 91's used mechanical speedmoeters, so the problem is either the speedmeter itself, the cable, or the gear that connects it to the tranny.

At the bottom of that link there is a Q&A that fits your speedometer/ABS problem really well, except it doesn't apply to a 91.

TO bind up the speedometer cable and also mess with the ABS, must have hit something hard at 5-10 mph