Hi Guys, Im having a problem with my 06 250 superduty (gas, 28k miles) speedometer. About 2 months ago I as pulling the RV down the road, running about 60 mph, and the speedo started slowly dropping off until, after 10 miles or so, it went all the way to zero and stayed there. When I would come to a stop, when I took off it would come partially up, then drop back off, then it quit working all together.

The next day it worked fine, and havent had any more trouble out of it.

Yesterday I look down and its sitting at about 25 mph faster than Im actually driving. (dead stop its sitting on 25, when Im running around 70 its close to 100)

as far as I can tell the odometer was working fine during both of these events. Any ideas as to what the problem could be (bad cluster?)

 

How old are the batteries in the truck?

 

Check your VSS sensor in the rear end. Clean it off, and if that doesn't fix the problem, try replacing it.

I'm guessing you're out of warranty due to time...?

 

Ive had the truck about a year, so Im assuming the battery is the original.

Yep, definitely out of warranty

Ive drove the truck several times, and each time I parked, the next time I started it the speedometer had dropped by 5 mph until it reached where it was supposed to be. Ill go ahead and pull the vss and clean it, but since its back to normal (again) Im assuming the only way Ill know if I fixed the problem is if it doesnt happen again
Thanks guys! I would have looked in the wrong direction