fixed my speedo, FAIL!

[lil hoodlum]

Oh boy! Today was my second attempt at fixing my speedometer. My 3 speed saginaw has been leaking fluid for quite some time and I decided about a week and half ago to fix the leaking. One of the more troublesome leaks is at the part where the speedometer cable goes into the tranny. I bought a replacement, you cut to fit, inner speedo cable. I took the cable out and first verified that there is a speedo drive gear in the tranny. Found it. Ok, that's good. Next I tried to replace the O-ring on the adapter. Bought several sizes as I didn't know what size was needed. None of them fit. I said to heck with it and proceeded onward. I wrapped some teflon tape on the threads hoping that would help some. I cut the replacement inner speedo cable 1/4 longer thinking the one from LMC on previously wasn't making solid contact. I put everything back together and added more fluid to transmission.

Keith

[lil hoodlum]

Old speedometer driven gear on left, new one on right which was working so who knows.

Took the truck for a little test drive and the speedometer still doesn't work. CRUDDD!! I unhook the cable from the back of the speedo and can feel the inner cable spinning as I drive. I can spin the back of the speedo and the needle does jump.

Oh yeah, and the tranny is still leaking. DOUBLE CRUDD!

Pretty frustrating, spend around an hour and a half in 104 degree weather trying to fix this thing.

Keith

[C10-Driver]

Is it leaking out past the inner part of the threaded collar? If so, I had this same problem... Unscrew it, pack it full of grease, screw it back in and see if that works. An old mechanic friend of mine suggested it to me and it solved my problem.

[lil hoodlum]

It turns out that some of the leaking is coming from the cable itself where the metal part is crimped on to the line. I tried to pinch is closed with a pair of vise-grips. It didn't seem to help much.

So anyways,

I bought a complete gauge cluster from Yanks2002 from the board. I thought that possibly that the back of my speedometer gear is rounded out. The cable itself has square ends for those who don't know.

I pull out my guage cluster to replace the speedometer. All of the other gauges looked nicer than the ones that were in my cluster so I decided to replace them as well. Not too bad of a job. Took me about an hour and a half but I worked indoors for part of the time. I finish replacing all of the gauges and re-install the cluster. Hook everything back up. Took it for a little test drive and the speedometer is still not working. I verified that the back of the speedo is not rounded out. My old one was fine too.

I'm thinking that my cable replacement didn't quite work out as I had hoped for. I again unhooked it from the speedo and verified that it does spin in my hand as I drive.

So I'm narrowing it down to replacing the speedo cable with a new one, not from LMC. The driven gear maybe a little too worn or that the drive gear on the transmission output shaft may need replacing.

Oh yeah, the gas gauge is now working properly. It actually reads correct and doesn't bounce around. My "old" new gas gauge was also purchased from LMC as well and has never worked correctly.

Tried to fix the speedometer, FAIL. Inadvertantly fixed the gas gauge, SUCCESS!!

Keith

[lil hoodlum]

Originally Posted by C10-Driver

Is it leaking out past the inner part of the threaded collar? If so, I had this same problem... Unscrew it, pack it full of grease, screw it back in and see if that works. An old mechanic friend of mine suggested it to me and it solved my problem.

It seems like it is also leaking from there. That is why I wrapped the threads with teflon tape hoping that would help some.

I'll order another cable from somewhere else besides LMC. When I have everything apar I will try the packing it with grease to see if that helps.

Thanks for the info,

Keith

[lil hoodlum]

My old speedo. I tried to get a close up of the back of it. It is not rounded out. The cable fits pretty snugly. When I am driving with cable unhooked, I can feel the inner cable spinning. If I put a little pressure on it though it will quit spinning.

Keith

[lil hoodlum]

Pictures of replaced gauges. They look so much better.

Pictures of leaking as of today.

Keith

[fastwillie 696969]

just looking at the drip hanging drives me nuts ,i hate oil leaks and its hard to find real good gaskets like the old days must be a asbestos thing

[lil hoodlum]

I hate leaks also. This transmission has been leaking for quite a while. I just keep adding more gear oil. I'm wanting to take my truck for a cruise to go camping or something that is more than an hour away from home. I just don't want to be worrying about the trans losing oil along the way and it seizing up. That's why I'm trying to fix it now. It's my daily driver but if I can't fix it the next time I try again I will put it in a shop to have it rebuilt and sealed up. I'm just hoping I can fix it.

Keith

[chevytruckluver]

ok, dont giveup just yet! I have tried to use those replacement cables before and without much luck. If you can stop it from turning while you are driving there is your problem, it is most likely that the crimp on drive end is slipping.
Also there is a seal inside the trans adaptor where the blue gear rides.
I would reinstall the old cable and instead of driving the truck I would undo the cable at the trans and attach a battery operated drill to the cable to spin it. If you do that and cant stop the cable by hand then attach it to the back of the speedo. You may have a hard time finding that seal at places like autozone but the easiest thing to do would be take the little adaptor to a transmission shop and have them put in the seal for you.
just a fyi you should use some graphite inside the speedo casing
good luck