I'm on my second replacement selector cable for my '87 GT and am wondering whether anybody knows why it fails. Rodney Dickman stated in an old post that heat is the biggest factor causing the selector cable to fail. My question is, "what is it about the heat that causes the cable to fail?" Others claim that water gets into the cable housing and causes the cable to rust. Which is it? Heat? Rust? Both? Is the cable sheath/liner made up of material like plastic that degrades, melts or swells? Has anyone ever cut one of these suckers open to find out what's going on when they fail? My car is garaged and taken out rarely when it's not raining so I can't imagine water getting into the cable housing.

Rodney mentioned that some of his earlier versions of the selector cable had problems and that his selector cable has been redesigned and is much better. I must have purchased one of his earlier versions because his cable is the one that I'm replacing with one of his newer versions.

quote Originally posted by Mr. Farknocker: Has anyone ever cut one of these suckers open to find out what's going on when they fail?

Not trying to be a smart-ass, but it seems to me that you're (unfortunately) in a position to now find out. Tell us what you discover!

My personal opinion is that it's water getting into the transmission end of the select cable that's causing the issues. I know mine has water in it, because in frigid weather, the cable is frozen in place, and won't move until engine bay heat melts the ice. Fortunately, we don't get weather that cold here on the coast too often.

Water getting in the cable is a common issue. I believe that Rodney has installed a rubber cap over the end of the sheath that helps to keep the water out.
Heat can damage the cable if it is routed near any exhaust parts. I also believe that Rodney's cables have an insulating sleeve around a good portion of the cable.
Regardless, his cables are the best replacements you will find. (I have bought several of them over the years. Just not handy to check the exact details. My cars are down the hill, in the shop.)

[This message has been edited by Raydar (edited 01-26-2022).]

My plan is to salvage the existing cable if I can by lubing it up. If that fails, I will do some destructive testing to see what's going on and report back here. Rodney's cable has rubber shielding around the exposed end that is connected to the transmission. Because it is made of rubber, I can't imagine the shielding to holding up for long (i mean years, here). If water is the culprit, perhaps some sort of aluminum shield or cover over the assembly would help. I do recall that the end of the cable where it's connected to the transmission is under the left ventilation grill so exposure to rain water (or even water from car washing) could be a factor.

Check out my thread from last year. My cable is still okay

Bob

quote Originally posted by treborerellim: Check out my thread from last year. My cable is still okay

This'll make it a bit easier to find. Select cable

The transmission end of the select cable points up, so when the end gets splashed, water will flow down between the cable and housing. End seals and boots help prevent this, but don't last forever. The quality of rubber used in aftermarket assemblies is universally inferior to OE rubber.

The routing of the cable allows the water that enters at the transmission end to collect in the low spot along the firewall. There it can rust, seize, freeze, etc. and cause problems.

I think it's a combination of things. As mentioned above, the cable end (in the engine bay) points straight up. So water can seep down into the cable. Plus it runs near the hot exhaust. And it makes a pretty tight turn to go through the firewall. I think all these things combine to make the cable rust and seize up.

When one of my select cables failed, I sprayed penetrating oil in one end, until it started dripping out the other end. Then I worked the cable back and forth by hand, to see what yummy stuff the penetrating oil would wash out. LOTS of rust! So apparently, the cable rusts up and the rust eats away the lining inside the cable. Then it starts to bind up.

Rodney Dickman sells a select cable with a better seal on the end. If you pack that seal with grease, the cable should last a long time.

[This message has been edited by Blacktree (edited 02-01-2022).]

I have one of Rodney's cables installed in an 88 Mera. I was aware of the heat failure potential so he double insulated mine and I have had no failures in more than eight years of use. The seal and double insulation did the trick for me.

Nelson