I know there are many threads about this but I have read through them and haven't found a definitive answer. I am trying to determine the correct o-ring size for the cable tube to transmission. I have tried a couple of sizes and still have a leak on my 72. The cable I have had a plastic tube and I don't want to overtighten it because I fear it will crack. On my 70 it has a metal tube and I have never had a problem with a leak. My only choice now is trial and error by increasing the o-ring size and see what happens. Any help would be appreciated. Btw I cannot use the tophat seal, have checked or replaced all other possible leak sources and seals and I don't want to cap it off and downshift manually.

Thanks

 

I'm not really sure but it seems I used 2 orings on it, Or maybe that was on the dipstick. I had a bunch of leaks from kickdown cable, dipstick, shift linkage, speedo cable, all of them. I finally got them all fixed but it took a few tries. At first I thought my repair hadn't worked until I found it was another spot leaking. Believe it or not, I finally dusted insect spray (used for tomato plants, etc.) on bottom of trans, that shows up where it's coming from. Sounds crazy but works good!

 

Are you sure the plastic end of the cable isn't cracked where it goes into the trans? Are you sure there isn't a groove in the hole in the trans case? And tightening it more won't seal it. The O-ring slides into the trans case. More torque on the bolt doesn't change how it seals. The bolt just needs to keep the tube from backing out of the case.

 

Where are you getting the o-rings? If the leaks was sealed up snd then began to leak again, I question if the o-ring you are using is compatible with transmission fluid.

Your local transmission shop probably has or can order the proper o-ring. But as others mentioned, make sure the housing isn’t cracked.