I have a 91 Dodge Cummins 4x4 le with a 727 trans... The speedo is giving me trouble... a couple of years ago I replaced the Speedo with a dealer rebuilt... at that time the odo did not work but the speedo did... when I changed the speedo out neither did anything... I changed the vss and it worked... recently I pulled in for fuel and the speedo was working when I pulled out... the speedo was not working...

I checked the gear reduction part that is attached to the transfer case and connects to the vss... that is working...

I am about to change the VSS again... do you think that is the right move? is this a regular problem with these units?

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I have found that the first replacement vss from my local dodge dealer was the old defective version of the VSS... There is a service bulletin on but the new improved Chrysler company in its wisdom only supports trucks up to 94... So unless you have an old time dealer with micro fische that goes back to your year of manufacture you are on your own...

The bulletin says that the old version of VSS was made with pins in the vss that were not strong enough for the job... they recognized this and made a new version with beefed up pins... Which NAPA has duplicated and sells for 60 odd dollars... They neer had any of the old version so you will not be blind sided by being sold the old version if you deal with NAPA...

The NAPA number for the right vss is vss100 which I got from a post from another Deisel Bomber regarding another issue...

I am posting this result for "to whom it may concern"