Intermittent code means?

antichip · #1 (**permalink**) 07-15-08, 07:28 PM

I posted a thread the other day about my tourque converter lockup clutch failure code. To my relief, y'all replied that all is not lost... Okay, now I lost the code and the my "5th" gear kicked in for about a day or so. I noticed the increase in MPG etc. Now its back. What does this mean? Perhaps some type of particle "?" or something is causing the failure? I understand how the clutch works, but I'm a bit fuzzy on how it is engadged? An electric device pulls on the clutch fork and pulls it in? So if the device failed, or was stuck, and then freed up, is this major good news for me and I should be under there wearing fluid about now? I need to know as I am prepared to change 11 quarts of fluid and the screens-however, if there is a part in there that needs to be replaced it needs to be done at the same time. I have no desire to do the nasty twice. If the part is cheap, should I just replace it any way? Or does it involve that much more labor? someone said it was a 12 hour job.........

ewill3rd · #2 (**permalink**) 07-15-08, 08:58 PM

Without going into painful detail....

The TCC is applied by a solenoid blocking a fluid passage (basically) routing fluid behind a clutch disk in the converter. The disk locks the two halves of the converter together mechanically to eliminate the characteristic torque loss from a fluid coupling of an "old school" converter.
(more efficient)

What causes the code to set is when there is a leak in the hydraulic circuit or a mechanical failure of the converter itself.
You could have a failing solenoid, leaking seals, gaskets, or worn hard parts causing the code to set.

An experienced tech will know what to replace to cover all the bases, yes it is an expensive and time consuming repair as the trans needs to come partially apart... and it aint held in by velcro.

antichip · #3 (**permalink**) 07-16-08, 10:46 AM

I am a fairly good mechanic and am confident that I could replace the solenoid. What I need to know is whether or not this will lead to transmission failure, and if so, how soon? I am planning to change the fluid etc and would be able to deal with an easy part swap while there. I have seen that it would be necessary to lower the cradle a foot or so. If you could point me in the right direction for doing this the right way, I would be very grateful. Especially the location of fasteners that would allow me to lower the support correctly.

carnut · #4 (**permalink**) 07-16-08, 04:27 PM

Dont know what type or year of car you own? List it in your profile signature please. Also you say 5 speed automatic? are you sure?

ewill3rd · #5 (**permalink**) 07-16-08, 09:35 PM

If this is a N* you have a 4T80.
Tearing into that trans is not fun or easy. Even an Experienced DIYer could quickly get over their head.
It isn't a matter of just replacing a solenoid, there are several seals and gaskets that would need to be replaced and probably the converter itself. (depending on what car we are talking about)

To tell you how to do it would require a great deal of time and effort that frankly I just don't have to give.
A factory Service Manual (FSM) would outline the required procedures, and there are bulletins available to the public that identify suspect parts. If you really want to do it yourself you'd have to gather that information and the tools you'd need and tear into it.
I don't do much trans work these days so me giving you instructions might not be very effective either.
Maybe someone else would take this project on.
At any rate, best of luck with your issues.