I've got a 96 F350, 2WD, 90k miles, and I just swapped the speed sensor the other day. I bought it at Autozone, and put it in last week. This morning, I walked outside to it, and there is fluid in a puddle underneath the diff, and the fluid trail leads back to the VSS. Are there torque specs for the VSS, or is there another problem I could be having?

 

You didn't cut the o-ring on the when you installed it by chance? I have read it is best to use a Motorcraft VSS, over parts house ones.

 

well I'm looking underneath it and the O-ring is slightly visible. I'm wondering if it slid out out and the fluid is coming out. I also heard something about a vent or breather tube could be stuck and now it's coming out the VSS, but I feel that since it's happening so soon to it being replaced that it's more likely installation error/defective part...

 

It's got to be seated properly. While you're under there, check the vent tube and make sure it's not plugged. The hose/tube broke on my 02 at the nipple that screws into the axle and was plugged up. Caused a wheel seal to leak. Fixed the tube, but seal continued to leak, though not as bad. Had to fix that too.

 

The I removed the sensor and replaced it, but this time, I pressed it in a little better. O-ring wasn't messed up. The vent tube is in bad shape, so when I go to work tonight I'll buy a new hose and some more fluid. Ran it for a little while around the block and it isn't dripping so I'll call that a win. The tube is all hardened up and it looked like a muddobber made its home inside it, so I'm just gonna put a new one in. Hopefully this sensor fixes the other issues that I've been having lately. If not, it's the solenoid and I just changed the trans fluid. I don't want to have to do it again...