Saturday morning speedometer project.

[Racin_jason]

So I currently only have one hurdle stopping me from getting my truck safety checked and driving on the road. The speedometer. I originally thought that it could be the cable that needed to be replaced but when I removed the cable and spun it either by hand or by a drill it would spin fine and not bind or jump as i had previously suspected. When I attached it to the speedometer and spun it by hand or by the drill it would read what i can only assume is perfectly . Seeing nothing at all before this was a big step in the right direction. After I got this far I removed the bullet housing the speedo gear. This was my prime directive all along as it was leaking and I figured i should replace the seals and such. When i removed the bullet from the transmission i checked the fitment (gear to cable) and everything seemed savvy So I replaced the seals and crammed everything back together. Went for a tour around the block and NOTHING was working again. so here I am.

Has anyone else had such devious happenings hold them up in this situation?

[geezer#99]

You might have the wrong gear in it. Too small. Doesn't mesh with the drive gear inside.
Or!!!
And this is the likely culprit!!
The drive gear is just spinning freely on the output shaft. It has a clip to hold it in place.
Pull the bullet again and reach in to the drive gear and see if you can slide it either way on the shaft. It shouldn't move.
Replacement clips are available.
You have to pull the tail housing to replace it though!

[68Timber]

The ratio adapters are bad about getting dirt/grime built up (and/or freezing) and shearing a tooth. I also had one shear the metal drive key. If it is none of the above, it'd just about have to be in the trans. Oddly enough, all that is driven by plastic gears although I haven't read anything about them failing.

[Racin_jason]

Originally Posted by geezer#99

You might have the wrong gear in it. Too small. Doesn't mesh with the drive gear inside.
Or!!!
And this is the likely culprit!!
The drive gear is just spinning freely on the output shaft. It has a clip to hold it in place.
Pull the bullet again and reach in to the drive gear and see if you can slide it either way on the shaft. It shouldn't move.
Replacement clips are available.
You have to pull the tail housing to replace it though!

this could be the problem I just took the truck around the block and I pulled the cable from the back of the gauge and it didnt spin at all while driving.

EDIT: I just took the bullet back out that the internal gear doesn't appear to be meshing at all.

[homemade87]

Racin , Its possible someone has installed the wrong type gear to mesh with your drive gear. http://www.transmissioncenter.net/sp...n_______va.htm

[Axle]

I had that occur on my '81. 5 miles from picking it up the speedo started bouncing a bit and went dead. Had my GPS with me so used it for my speedometer instead.
Anyway, my speedo bullet had a lot of movement in the housing, I ran a tywrap around the speedo cable where it exits the bullet and around the crossmember to keep the speedo gear engaged with the tailshaft drive gear.

Alex.