our newest problem is the speedometer on our '40 kc...while driving, the speedo started to bounce, then began to meke a grinding noise, and finally the needle began to jump up to the 100mph end of the scale...

I've disconnected the cable to prevent further damage, but what's the problem likely to be and will I have to remove the entire gauge cluster to get at it?..

epi

Lubricate the speedometer cable inside of the housing and then try it again. If the speedometer needle is still erratic, then the speedometer head must be lubricated. Your local speedometer shop can do this for you as well.

dog,

speedo cable lube on the cable?..what lube to use on the speedo head?..do I have to remove the head to lube it?..

thanks skip,

epi

Chevrolet, I am sure Doggy-breath would agree that if the speedometer is still acting funny after you lube the cable,it should be removed from the dash and taken or sent to a good speedometer shop. you should just lube the lower part of the cable houseing, the rotation of the cable will carry the lube up the cable, the cable lube need not get into the head. also any over-the-counter stuff like WD-40 may work in the short term but in the long term it will leave an undesirable film in the speedometer head that will cause problems. good luck!

Oh as to what one should use for cable lube, my repair manual suggests a mixture of graphite and light oil, I cleaned the cable and houseing like Chevy Nut suggested, I put the bottom of the houseing into a coffee can half full of solvent and the head end lightly in a vise, then poured a mixture of WD40 and 20 wt oil down thru the houseing and while it was soaking cleaned the cable then put the cable in the housing spun it and poured more solution down and spun the cable till the fluid comimg out at the bottom was clean , blew out the housing and wiped the cable clean and used a small amount of light (20wt oil ) on the lower part of the cable. it looked and worked like new, cross my fingers........

mrmack & lil' johnny,

thanks for all the tips...I'll try it this weekend and let you know how it turns out...

epi

mrmack & lil' johnny,

did the wd-40 cable inspection & cleaning...

the cable was in fine shape, aside from being covered in black oil and the upper most (the end inside the cab) 8" completely dry and slightly rust-colored...is this cable normally self-lubed with tranny oil?..

if so, this indicates the poor condition of our tranny oil, then?..and perhaps that it may be low, if the entire cable isn't getting lube, or perhaps the cable housing was "plugged"...

well, it's clean now, but the speedo's still pegging out at the 100mph side, then bouncing back down while making a metallic gear noise, so I suspect we have a problem in the head...

how is the gauge cluster retained in the dash?..

just wanted to add that this truck has sat (only run around the ranch occasionally) for the past twenty years...

epi

Chevrolet, don't think that the tranny grease lubes the speedo cable, either you have a dirty speedo head or you are driving a way too fast for ranch conditions!

mrmack,

ugh...you mean that that oil that came out of the housing (looked liked unrefined crude) was all speedo lube?..

sometimes I think it's a wonder that this truck runs at all...

epi

can anyone tell me how do I remove the gauge cluster from the dash?..

epi

thanks everybody,

we re-installed the lubricated speedometer head & cable and now it works great!..smooth and quiet...

next time it comes out, we'll recondition the dial face...by then, hopefully, we'll know how to remove the whole cluster, as the paint under the glass is all cracked, peeling, & curled...a lovely sight...

epi