Help needed with erratic speedo on 96 Explorer

A few weeks ago the speedo in my 96 explorer started to behave
erraticly. The needle was bouncing up and down at all speeds. Also it
apeared to show the speed about 10-20 km/h too slow. At this time the
tranny was shifting very bad. After a about 5 days driving with this
erratic speedo it stoped moveing at all. At this time I suspected that
there was some problem with the VSS and I removed it for inspection.
The plastic gear that drives the VSS apeared to be worn, not mutch but
I replaced it with a new one. Now the speedo moves again but it still
bounces erraticly and it still apeares to show the speed to slow. I
talked with a tech at the local Ford shop and he said that had never
seen this problem but his guess was that the VSS is broken, so I
purchased a new one and replaced it. It made now difference. Now I'm
realy stuck with this problem and I need your help.

Best reagards

Patrik from Sweden

The VSS "teeth" are plastic as is the other end in the transfer case,
both sides get worn out - did you replace both? May or may not be your
problem, but I found that out the hard way, after first replacing the
VSS side and then GEM module (per the service manual troubleshooting
guide)

Does your cruise control work - or does the speed bounce around when in
cruise control?

pac wrote:
> A few weeks ago the speedo in my 96 explorer started to behave
> erraticly. The needle was bouncing up and down at all speeds. Also it
> apeared to show the speed about 10-20 km/h too slow. At this time the
> tranny was shifting very bad. After a about 5 days driving with this
> erratic speedo it stoped moveing at all. At this time I suspected that
> there was some problem with the VSS and I removed it for inspection.
> The plastic gear that drives the VSS apeared to be worn, not mutch but
> I replaced it with a new one. Now the speedo moves again but it still
> bounces erraticly and it still apeares to show the speed to slow. I
> talked with a tech at the local Ford shop and he said that had never
> seen this problem but his guess was that the VSS is broken, so I
> purchased a new one and replaced it. It made now difference. Now I'm
> realy stuck with this problem and I need your help.
>
> Best reagards
>
> Patrik from Sweden

My cruise control is a mess. It runs the car by the speed the speedo
shows, so if the speedo dips the cruise control starts to accelerate
even if it alredy runs at the speed it was set to.
I found a thread in another forum that points to the "inside" gear. So
I guess I will be changing that one too. Heres a link to the forum:
http://www.explorerforum.com/forums/...5&page=1&pp=20
I will let you know how it goes

Len skrev:

> The VSS "teeth" are plastic as is the other end in the transfer case,
> both sides get worn out - did you replace both? May or may not be your
> problem, but I found that out the hard way, after first replacing the
> VSS side and then GEM module (per the service manual troubleshooting
> guide)
>
> Does your cruise control work - or does the speed bounce around when in
> cruise control?
>
> pac wrote:
> > A few weeks ago the speedo in my 96 explorer started to behave
> > erraticly. The needle was bouncing up and down at all speeds. Also it
> > apeared to show the speed about 10-20 km/h too slow. At this time the
> > tranny was shifting very bad. After a about 5 days driving with this
> > erratic speedo it stoped moveing at all. At this time I suspected that
> > there was some problem with the VSS and I removed it for inspection.
> > The plastic gear that drives the VSS apeared to be worn, not mutch but
> > I replaced it with a new one. Now the speedo moves again but it still
> > bounces erraticly and it still apeares to show the speed to slow. I
> > talked with a tech at the local Ford shop and he said that had never
> > seen this problem but his guess was that the VSS is broken, so I
> > purchased a new one and replaced it. It made now difference. Now I'm
> > realy stuck with this problem and I need your help.
> >
> > Best reagards
> >
> > Patrik from Sweden

Problem solved. The replacement of the speedo gear fixed the problem.
Now the speedo is accurate, the tranny is shifting ok and the cruise
control is also working.

Best regards,

Patrik


pac skrev:

> Removed the "inside" gear today and it was realy worn out. The teeth in
> the middle of the gear were the VSS connects are almost gone completly,
> so I have now orderd a new one.
> I just wonder why the gears get worn?
> pac skrev:
>
> > My cruise control is a mess. It runs the car by the speed the speedo
> > shows, so if the speedo dips the cruise control starts to accelerate
> > even if it alredy runs at the speed it was set to.
> > I found a thread in another forum that points to the "inside" gear. So
> > I guess I will be changing that one too. Heres a link to the forum:
> > http://www.explorerforum.com/forums/...5&page=1&pp=20
> > I will let you know how it goes
> >
> > Len skrev:
> >
> > > The VSS "teeth" are plastic as is the other end in the transfer case,
> > > both sides get worn out - did you replace both? May or may not be your
> > > problem, but I found that out the hard way, after first replacing the
> > > VSS side and then GEM module (per the service manual troubleshooting
> > > guide)
> > >
> > > Does your cruise control work - or does the speed bounce around when in
> > > cruise control?
> > >
> > > pac wrote:
> > > > A few weeks ago the speedo in my 96 explorer started to behave
> > > > erraticly. The needle was bouncing up and down at all speeds. Also it
> > > > apeared to show the speed about 10-20 km/h too slow. At this time the
> > > > tranny was shifting very bad. After a about 5 days driving with this
> > > > erratic speedo it stoped moveing at all. At this time I suspected that
> > > > there was some problem with the VSS and I removed it for inspection.
> > > > The plastic gear that drives the VSS apeared to be worn, not mutch but
> > > > I replaced it with a new one. Now the speedo moves again but it still
> > > > bounces erraticly and it still apeares to show the speed to slow. I
> > > > talked with a tech at the local Ford shop and he said that had never
> > > > seen this problem but his guess was that the VSS is broken, so I
> > > > purchased a new one and replaced it. It made now difference. Now I'm
> > > > realy stuck with this problem and I need your help.
> > > >
> > > > Best reagards
> > > >
> > > > Patrik from Sweden

Another one of the Ford inferior "minor plastic" parts that take a heck
of an effort to replace - like the "blend door" in the same model year
Explorers. While planned obsolescence comes to mind - I don't think the
Ford engineer's are smart enough for that. In switching from metal to
plastic components, they used material that just does not have the
durability required. And not a big deal to Ford because it never fails
in the warranty period... but it may well keep me from buying another
Ford.

pac wrote:
> Problem solved. The replacement of the speedo gear fixed the problem.
> Now the speedo is accurate, the tranny is shifting ok and the cruise
> control is also working.
>
> Best regards,
>
> Patrik
>
>
> pac skrev:
>
> > Removed the "inside" gear today and it was realy worn out. The teeth in
> > the middle of the gear were the VSS connects are almost gone completly,
> > so I have now orderd a new one.
> > I just wonder why the gears get worn?
> > pac skrev:
> >
> > > My cruise control is a mess. It runs the car by the speed the speedo
> > > shows, so if the speedo dips the cruise control starts to accelerate
> > > even if it alredy runs at the speed it was set to.
> > > I found a thread in another forum that points to the "inside" gear. So
> > > I guess I will be changing that one too. Heres a link to the forum:
> > > http://www.explorerforum.com/forums/...5&page=1&pp=20
> > > I will let you know how it goes
> > >
> > > Len skrev:
> > >
> > > > The VSS "teeth" are plastic as is the other end in the transfer case,
> > > > both sides get worn out - did you replace both? May or may not be your
> > > > problem, but I found that out the hard way, after first replacing the
> > > > VSS side and then GEM module (per the service manual troubleshooting
> > > > guide)
> > > >
> > > > Does your cruise control work - or does the speed bounce around when in
> > > > cruise control?
> > > >
> > > > pac wrote:
> > > > > A few weeks ago the speedo in my 96 explorer started to behave
> > > > > erraticly. The needle was bouncing up and down at all speeds. Also it
> > > > > apeared to show the speed about 10-20 km/h too slow. At this time the
> > > > > tranny was shifting very bad. After a about 5 days driving with this
> > > > > erratic speedo it stoped moveing at all. At this time I suspected that
> > > > > there was some problem with the VSS and I removed it for inspection.
> > > > > The plastic gear that drives the VSS apeared to be worn, not mutch but
> > > > > I replaced it with a new one. Now the speedo moves again but it still
> > > > > bounces erraticly and it still apeares to show the speed to slow. I
> > > > > talked with a tech at the local Ford shop and he said that had never
> > > > > seen this problem but his guess was that the VSS is broken, so I
> > > > > purchased a new one and replaced it. It made now difference. Now I'm
> > > > > realy stuck with this problem and I need your help.
> > > > >
> > > > > Best reagards
> > > > >
> > > > > Patrik from Sweden