is my speedo about to go or what??? I'll be driving and then all of a sudden the speedo will go from 60 down 10 back to 60 to 0 back up to 35-30 back to 60 then Ii'll slow down and she evens back out to normal spped that I'm going whats up ????


scott

 

It could be. What year is your truck? 1992-up have a totally different system than older trucks.

 

If it's a 92-96 than do a search for "bad PSOM" thats a common problem and you'll easily find you answer. If it's 91 and older, it's probably the little plastic gear in the tranny for the speedo.

 

sorry forgot to include that info..

it's a 93 150 ext cab. 5.0 Eod tranny

 

The PSOM is probably dying, but pull the ABS sensor out of the rear diff and clean any metal filings off the magnetic tip. If there are a lot, you've probably cured it; if it's already clean, start shopping for a used PSOM (speedometer) or complete cluster. The PSOM should go for $20-40 and a whole cluster (non-tach) $40-60, (tach) $50-80.