dexter860 Posted January 16, 2016 Share Posted January 16, 2016 The speedo in my truck is going whacky starts out fine then after a while the needle will fall down and read about 40 mph slower than I'm going? I replaced the tailshaft sensor, and does the same thing, could it be the speedo itself? Yoke seems tight on tranny, truck doesn't throw any codes, thanks. Quote Link to comment Share on other sites More sharing options...
Kansas farmer Posted January 16, 2016 Share Posted January 16, 2016 I'm not sure is it electronic or a cable? Quote Link to comment Share on other sites More sharing options...
Dirtymilkman Posted January 16, 2016 Share Posted January 16, 2016 It's either the speedo itself or the printed circuit board. The printed circuit was a very common replacement. 1 Quote Link to comment Share on other sites More sharing options...
dexter860 Posted January 16, 2016 Author Share Posted January 16, 2016 Ok, its electronic, I'll look into that circuit board deal. Quote Link to comment Share on other sites More sharing options...
MackMack613 Posted January 28, 2016 Share Posted January 28, 2016 It's probably the head itself, my 93 did the same thing. When you pull your old one call your local mack and give them your info and ask what the switch positions need to be, set the switches on the new one and you should be good to go 1 Quote Link to comment Share on other sites More sharing options...
bbigrig Posted February 8, 2016 Share Posted February 8, 2016 What he said^^^. No board. Just a head and set the dip switches on the rear. Fairly common and you should have an electronic speedo sensor that ties into V-mac. The switches will be based on tire size, axle ratio etc. The dealer may need your vin and they can cross it over from there. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.