Hot Rod Forum banner
1 - 12 of 12 Posts

·
Registered
Joined
·
429 Posts
Discussion Starter · #1 ·
Ok I have figured out an issue with this trans, the kick down cable is seizing up and causing it to shift funny.

Now may question is what is causing this seizing, Looking at the outside of cable I see no damage this cable is new and this is not the first one that had this happen.

Is it melting internally, reason I say this is I can pull on it (with force) and it will move but not return.

This car runs at 190 degrees, but you feel a lot of radiation heat for under car and off the exhaust. Car has 2 " dual, I zip tie the cable to the trans to keep it away for exhaust.

Baffled
 

·
True Hotrodder
Joined
·
1,955 Posts
The cable comes into the case and attaches to a linkage at the valve body - doubtful anything is melting. But the connection at the VB is a bit convoluted and it could have somehow gotten twisted causing your issue. Best to obtain a new cable and replace it.
 

·
Registered
Joined
·
429 Posts
Discussion Starter · #3 ·
Thanks for input Chas, I have done that in past, this is not first cable it has happened too. I have replaced at least 2 and thinking I messed something up on install.

All fail the same they seize up internally, housing is not crushed, or melted.

Something is taking place internally, I don’t know if cable is getting hot and melting inside but I see nothing externally, or could cable be acting as a ground and welding to metal inside.

I have grounded the engine to the frame, I have grounded the battery to engine, I have a jumper from battery to fender, I have ground from cylinder head to firewall, I have wire harness grounded several places under the dash and in engine compartment and in trunk.

This one has me baffled, again I thought bad install but this at least 3rd cable to fail like this, so something is wrong.

They last about 600 miles and then they are done. Only thing I can come up with is heat or ground issue some how.

We have talked about swapping to a 200 or 700 over drive, but this cable is going bad on a turbo 350 is a pain, if it goes bad on an over drive unit it will cook the trans.
 

·
True Hotrodder
Joined
·
1,955 Posts
Thanks for input Chas, I have done that in past, this is not first cable it has happened too. I have replaced at least 2 and thinking I messed something up on install.

All fail the same they seize up internally, housing is not crushed, or melted.

Something is taking place internally, I don’t know if cable is getting hot and melting inside but I see nothing externally, or could cable be acting as a ground and welding to metal inside.

I have grounded the engine to the frame, I have grounded the battery to engine, I have a jumper from battery to fender, I have ground from cylinder head to firewall, I have wire harness grounded several places under the dash and in engine compartment and in trunk.

This one has me baffled, again I thought bad install but this at least 3rd cable to fail like this, so something is wrong.

They last about 600 miles and then they are done. Only thing I can come up with is heat or ground issue some how.

We have talked about swapping to a 200 or 700 over drive, but this cable is going bad on a turbo 350 is a pain, if it goes bad on an over drive unit it will cook the trans.
Or are we repeating the wrong installation? When I first started working on transmissions - that was in mid 80's - I had purchased a used TH400 for my bracket car. 10-12 passes and the trans was toast. I was ticked but I had bought it used. So bought a rebuild kit and tore it apart. Maybe got 15 runs that time - pulled it and did it again - yes I know the mark of insanity here. Same again about 15 passes. This time I start really looking at stuff, the VB had a single check ball in it and I had made sure to put it back in the same spot each time - it was the wrong spot of course. I moved it where it was supposed to be and sold that trans years later with about 200 passes on it.
 

·
Registered
Joined
·
95 Posts
install the cable with the pan off and before you hook up the new one, move the linkage at the VB with your hand a few times to make sure it returns on its own.If it’s good hook up the cable and adjust it. Then get someone to work the pedal while you watch the linkage from underneath. If it works properly,put the pan on. Add a ground cable from a bell housing bolt to the frame. We used to add the ground cable on all the GM cars with a cable operated shifter in the 80’s.
 

·
Registered
Joined
·
15,319 Posts
The kick down cable is just another maintenance item, they like foot throttle and TV cables don’t last forever. The inner cable is riding inside a plastic sheath, the cable assembly has arcs to bends and twists which place loads of the wire cable against the plastic guide. These things wear eventually through allowing the inner cable to rub on the outer overbraid till something becomes entangled to snag or break the cable.

Bogie
 

·
Registered
Joined
·
429 Posts
Discussion Starter · #9 ·
ok guys here's a little update, I removed kick down cable and I forensically cut this cable apart to find where the failure is taking place. My investigation has narrowed it down to the transmission end of the cable. In fact its starts to show issues 6" up from the transmission end of the cable (measured from the top of plastic part that mounts to the trans) and goes as far as 15" up from the transmission end of cable so a 9" window.
The first item I see at both these ends is oxidization in the form or white powered like this cables been exposéd to the elements, this cable was new in march.
Ok as I continued to narrow down the actual failure area it falls very close to dead center of this window say the 8" to 12" area, the failure area is about 3" long.
This 3" section appears to have melted internally and then solidified, but the outside casing was not melted and the internal spring wrap shows no sign of exposure.
I have attached a few up close up photos, let me know your thoughts.
 

Attachments

·
More for Less Racer
Joined
·
20,942 Posts
Sure looks like heat damage, the inner plastic coating/sleeve has been melted for sure. Just odd it didn't show on the outer casing too.
I've had the Morse type red plastic skinned cable that B&M and most others use for shifter cable do that, melt and solidify and lock up....but it was obvious on the outer casing too that it was melted as it was starting to ripple and sag..
 
1 - 12 of 12 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top