VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 1931 Speedometer cable leaking at transmission

1931 Chevrolet - My Speedometer cable is leaking where it connects to the transmission. The connection seems tight and the speedometer works fine.
Are there any seals or other methods to prevent leaking? I'm using 600W oil.
If required, where can I get parts? Thanks

I used an o ring inside the cap that screws on to the transmission. I think there was an old piece of felt or cork inside when I started.

Dave

I used an o ring inside the cap that screws on to the transmission. I think there was an old piece of felt or cork inside when I started.

Dave

Hello jtrue,
Dave39MD is probably correct about a leaking oring or other seal within the screw-on speedo cable cap. In order to be sure of where the leak is at, clean (brake clean) and dry in a good size area around the speedo connection. Verify the transmission is properly serviced with lube. Go for a short drive. Dust speedo area with talcum/baby/foot/whatever powder for the true location of the leak. With lube migrating everywhere, it's hard to tell what is leaking. Maybe the cap is cracked or deformed from excessive tightening, maybe somewhere else.

originally there was only a round felt washer.

main reason for leaks is overfilled transmission.

also make sure that your speedo cable goes UP HILL away from transmission, it it SLOPES DOWN then fluid will find its way !! once it starts weeping hard to stop.

Thanks for the quick input. Now I know what to be looking for. I'm make a washer and see how it works.

If you find that it is actually the cable and not the fitting that is leaking, I used adhesive lined shrink tubing to cure the leak I had on the cable and at the joint with the cable and the ferrule. The cable stays flexible and leak free.

Hello 1931Harlet,
I had not heard of 'Adhesive Lined' heat shrink tubing before you mentioned it. Then I thought, how is it put into position? Are you able to slide the cap up the cable, apply the heat shrink, then slide cap back over heat shrink'd cable? Tell us what you did to install this tubing. Thanks. Harry

Hi Harry, I had to remove my speedometer cable to have the inner cable repaired due to a frozen speedometer. While I had it out, I noticed a large "rub" spot caused by the brake cross member and figured it was going to be a leaker. Anyway, I didn't want to purchase a new speedometer cable, I decided to try some shrink tubing. I found some shrink tube (on the innerweb) at a place called "electriduct", 1650 NW 18th Street, Unit 801, Pompano Beach, FL, 33069. The size I purchased was 3/4" medium wall heat shrink (3:1) - 4 foot length. SKU HS3-MW-075. Cost was $8.99 and $14.34 for shipping (can you believe it?). The 3/4 inch is large enough to fit over the ferrules and the 3:1 shrink ratio will fit tight on the cable and the adhesive should hold and seal it in place. All I did was to clean the outside of the cable with good old brake clean, cut the tubing to length, enough to cover both ferrules and a little bit for shrinkage (I covered the entire length of the cable) and heated the tubing with a heat gun. Make sure that the tubing does not move off the ferrules while heating. The heat will activate the adhesive in the tubing and cause the tubing shrink around the cable. Be careful the adhesive can burn if it oozes out of the tube while heating.
Regards,
Harry(1931Harlet)

Hello 1931Harlet,
Nice repair to the speedo cable housing. I'll keep it in mind if the need arises. When you removed the cable housing from your 31 for the repairs, was only one 4-foot long shrink tube long enough to do the entire housing? I do not know how long a speedo cable housing is.

Harry,
A 4 foot piece is long enough to do the entire cable and ferrules.