i have just purchased a black 93 bronco 351w with an automatic/od, the truck runs and sounds great. the only problems i havent been able to fix are the speedometer and transmission. when i bought the truck the speedometer and odometer didnt work, and on the way home i felt the truck shifting hard. also my ABS light is on. i read some where this all could be related to an ABS sensor, but i have no clue. please post your thoughts -is it all related?- or -is it a series of different things?-

 

You are dealing with a failed or dirty VSS (Vehicle Speed Sensor). Its mounted in the top of the rear axle housing and has a two-wire connector. This sensor relays (obviously) speed information to the PCM which in turn determines shift points and generates the signal to the speedometer. The information is also sent to the ABS computer for wheel-slip information. Yeah, one sensor and it does all that.

 

checked the vss and cleaned it off but still no luck any other suggestions

 

Wiring problem between the VSS and the PSOM (speedometer). Blown ABS fuse. Bad or unplugged PSOM.

Check your fuses, including the ones under the hood (the one for the cluster is under the hood), and if those all check out, start at the sensor and follow the wires to the cluster.

 

the tone ring in your rear diff could be messed up causing the vss to not work properly. pull the rear cover and inspect it. the vss may still need replaced to just because its clean doesnt mean its working

 

Same problem here....that's why I didn't start a new thread. Sensor has been replaced 3 times and STILL boinks out on me. It will reset in about 20 minutes but, until then, I lose my speedometer, odometer, cruise control, and overdrive. It will only reset if the truck is shut off.........a real PITA on a trip. Dealer though they found the problem.......driveshaft installed backwards in Fla. which caused excessive vibration. Since then, it has only messed up once. Dealer pulled the cover off the rear end, replaced oil and inspected, but found no problem. Thsi is a constant irritant and I want to fix it before I do much else to this truck........guy thing, lol. Any thoughts?

 

all it takes is one tone ring tooth to be off . you should inspect the rear gears/tone ring yourself. have someone turn the wheel while you watch the tone ring. any bent tooth or missing tooth and there is your problem. or like said the mlp solenoid is bad. have you pulled any tranny codes?

 

Not yet, but I will. Thanks for the answer. I'll check that tone ring out for any visible problems.

 

also if you have an LS in the back when you refill be sure to pick up the ls additive to go along with the proper rear end fluid . its a friction based fluid that protects the ls

 

My brother in law works at a Ford dealership, I seen him have to replace the speedometer head in a new F150 to fix the hard shifting problem.

 

to fix the problem i had to re-wire the sensor to main computer fixed the problem and has been working for two months