I am having a problem with my O/D light flashing and my truck shifting hard. Just started out of the blue. After reading a few other topics, I am hoping it is the VSS. Now if only I could find the dang thing. Anyone with a diagram, or detailed description on where it's at? Thanks so much as always!!

 

It's on top of the pumpkin on the rear end. You will see a two wire harness with a plug on the end leading to it. Takes about 10-15 minutes to replace.

 

So I am assuming I will need to elevate the rear end to have room to work? I know...probably a dumb question.

 

Not if it's a 4x4 but even on a 2X I really doubt that you need to raise it at all. That VSS is held in there by just one litle hex srew is all. Make sure to carefully wipe off the sealing surface before installing the new VSS.

 

No reason to elevate, come in from either the driver's or passenger side. When it's on the ground you can just about sit up underneath the truck.

 

Just did mine on my 03. Really easy. takes all of about minutes. Let me know if you have any further Q's.

 

guys I can't for the life of me find this thing. I looked all over the rear differential. I hope I have the right part...anyone have the napa part number or a picture? The NAPA part number I have is VSS311SB.

 

It's on top of the rear differential...it's just a little plug, it'll have a couple of wires coming out the front that run to the front of the truck.

It's held down with I believe a 3/8" bolt.

 

Is this it?

 

also I keep seeing a lot of talk about is it the VSS or the ABS speed sensor, and I am not sure which one I should replace. I bought the VSS, but I don't see it on top of the rear diff. I do see something that looks like the ABS sensor I saw on Advance Auto's website though.

 

Thats not what mine looked like, but it may be different on your 98 as compared to my 03.

Mine was kind of L shaped.

 

I think I have the wrong part....I think what I am looking for is actually called the ABS speed sensor for the rear differential...only thing is....my ABS light didn't come on. wierd. This is the only thing I see on top of the rear differential

 

This is the part in the rear diff.

 

That is it!

 

alright guys....thanks...looks like I will have to go buy a different part...NAPA sold be a VSS...and after looking all over my truck, I don't think my truck even HAS a VSS...it only has the ABS speed sensor for the rear differential. Well...that was a waste of several hours..