speedo issues

[gr8tdragon]

Hey guys, I have a slight problem with my speedometer. I will be cruising a long at a hundee and it will start bouncing all over the place for a second then work fine, then bounce again for second, then work fine for a while and will do the cycle all over again. I have a 2001 F350 with the 7.3L diesel in it. I think that this could be the speed sensor causing the problem. Let me know what you think or if you have encountered this before. If it is the speed sensor, where is it located?

 

[bigdaddy35]

It sounds like the speed sensor. The variable speed sensor (VSS) can be found on top of the rear diff housing.

Try cleaning it, but they're not too expensive.

 

[polarice]

if there is too much stuff on it might be a good idea to pull the rear diff cover off and do a fluid change