VSS/Speedo question

[Jh8990]

So I am pretty sure my vss just crapped out on me today, I was going around 60 and the needle just started jumping around and then just finally died and rested at 0 mph.

so I have an 92 mtx, I heard it is alot easier to change the vss on an mtx then on an atx, is that correct? and when I go to replace the vss is it possible to do from the top? or do I have to jack the car up and get at it from the bottom?

Thanks

- Justin

 

[jmpSHO2nd]

If it's an MTX you remove it from the top. Maybe a 10 min job.

 

[Jh8990]

sweet, I have never did it before and don't know exactly where it is located. but if I just follow the speedo cable down to the tranny I should find it pretty easily?

 

[jonheese]

What makes you say it's the VSS and not the speedo cable or head? It's much more common for the cables to bind/break/unwind/fail than for the VSS to die, all other things equal. Many time, a squirt of white lithium grease into the cable sheathing will "fix" them, if you catch it in time.

Does your cruise control work? If the VSS is dead, the cruise won't work, but if it's the cable or the speedo head, the cruise will still work.

 

[Jh8990]

I'll check if the cruise control works tomorrow.

and I don't know, my untrained mind just told me that when your speedo goes that its just vss. but where would I squirt the grease where the speedo attaches in the engine bay or behind the cluster?

 

[jonheese]

Well, it's best to squirt it into the "upper" end (behind the cluster), since gravity will assist it in covering the whole cable, but many people are kinda squeamish to do the ~15 minutes of work to get it out. You can get by with squirting it in the "lower" end, but try to hold it up and spin the cable core around a bit to work it in there.

Also, just to be clear, the best type of grease for this is the aerosol can of white lithium grease.

Now, I'm not saying "this will fix your issue," but if it doesn't, I'd bet you'll need to replace your speedo cable, and not your VSS. Unless you know something specific about your VSS that makes you think it's likely to have failed.

 

[Jh8990]

i will try your method first. so get the white lithium grease that sprays rather than the one in the tube?

and its not that big of a deal for me to take the instrument cluster out

 

[jonheese]

Yes, take out the cluster, unhook the speedo cable from the back of the speedo head, and spray the grease down the cable.

A tube might work okay, but the spray can is infinitely easy and takes ~5 seconds to totally coat the inner cable core with grease from top to bottom.