about 2 weeks ago i was driving and the needle on the speedometer dropped way down past the 0 it and it wouldnt move. so i took the cover off and pushed the needle back up past the 85 mark and then it need to be nudged back down to the 0 area. i though all was fine , i dont know why it would just fall past the 0 and stop working, but once i did my fix i i thought it was fine..... till i got stopped for a ticket . going 53 in a 40 zone. the needle was on the 45 mark.. sure didnt seem to me to be that much more. last nite though it went totally wacky and went to about 85 even though i wasnt . did i screw it up by pushing the needle? can i take the whole cluster out and fix it? i see the shop manual says something about a speed sensor.
by the way there was no speed limit signs on the road :burnout:
thanks for any input :D
1983-84 cars do not use the speed sensor on buttstuffog speedometers, although the transmission is supplied with a speed sensor at the end of the speedo cable. The speed sensor on cars equipped with the buttstuffog cluster are supplied for the optional tripminder feature if so equipped and possibly but (not verified by me) use of info for the engine computer.
I would check the speedo cable first and foremost. It may need replacement or it may just need to be checked that it did not slip off the back of the speedo unit. Sometimes the plastic clip that holds the cable on the back of the speedo will get brittle and break causing the speedo cable to not retain a tight connection.
The speedo cluster unit is usually very durable and will last a lifetime. You can check this my removing the cable off the back of the unit and seeing if the needle drops to zero. You can test the unit by rotating the back of the cable shaft with your fingers and see if the needle bounces up from zero and bounces up higher the faster you rotate it. The needle should drop back to zero when the rotation slows to a stop. If none of this happens then the speedo unit is defective.
If you by chance removed the needle from the cluster face then you may have to recalibrate it if it did not go back on in the same exact position. It's a little tedious but I did this on my recent Mustang to Tbird cluster swap just so I could custom paint the back of the needles aqua blue and replace them. I also did this on my original 84 granny cluster when I painted those needles the same color. Bascically what you do is remove the needle and rotate it counterclockwise until is rests at true zero. You know you are near true zero when the needle is rotated clockwise from zero just enough that the needle does not touch the stop pin at zero. Then rotate it just enough counterclockwise that it rests right onto the stop pin.
After that check the transmission side of the cable. Make sure it's tucked-in and clipped to the speed sensor properly. You can also remove the speed sensor and inspect the speedo gear for bad or worn teeth.
If you end up having to replace the speedo unit for some reason and cannot find one for a 83-84 car, be sure to look for any 1983-86 mid size LTD and Marquis. The speedo unit itself is the same and will remove from the donor cluster housing and swap into the Tbird cluster. You just have to remove your gauge face from the defective unit and swap it onto the replacement one. Also, 1980-82 Tbird and Cougar speedo unit will work since they were carried over for use in the LTD/Marquis. It is also not hard to resent the odometer mileage to your original. Just take pictures before and after of each speedo to document mileage authenticity. As long as the cluster unit is repaired and adjusted for actual mileage then you butt is covered.
hi watchdevil
i checked the cable and the plastic connector all is good. the needle just wont move properly anymore. so i sent the speedometer cluster to southern elctronics, i got the site from a link on erics coolcats site! but when i took the cluster out i dropped the needle and stepped on it :( wouldnt ya know it !! and then i didnt put the rest of the cluster back in .... jeez the car wouldnt charge without the warning lights cluster being connected. i hope to have it back before sat.
thanks
eddie