Transmission Clutch Converter Lock (TCC)

[91olds98]

Ok - I've made a few posts about this in the past, and I've got some new news and a few new questions.

This is still about my 1991 Olds Ninety Eight Regency Elite and its transmission. (Check out my other posts for previous info.)

I've been doing a lot of testing with the transmission, and have found that the TCC lock solenoid is definitely working - all the time. I can hear it clicking over when the conditions are correct, and know that the solenoid itself is working properly, as are the electronics that drive it. This means that the only possible solution for the TCC not locking in when it's supposed to would have to be in the hydraulics or the mechanical components of the torque converter lock itself.

I was thinking that it may be a pressure problem - the hydraulic system possible not getting enough pressure to engage the system. So, I changed the transmission fluid in the case that the old fluid was too thin, or worn out or something of that nature, but the problem got worse when I did this. Before I changed it, I was able to (at times) get the TCC to lock in, if I drove real lightly and kept the accelerator at 5% open. But after the change, I cannot get it to lock in at all - and it will occasionally lock in only for a brief moment when at cruising speeds, but only for an instant. I looked at the hydraulic patterns from the repair manual (I borrowed one from the local service shop) and wasn't able to diagnose anything, since I don't have the ability to remove the transmission or any of its covers.

So here’s my question: knowing the symptoms, can anyone tell me what might fix this problem? Of course a new trans would do it, but other than that, does anyone have any ideas on what I can do myself (short of rebuilding it myself) to make this annoying problem go away?

Please help me out if you can... ...this thing is driving me NUTS, and its killing my gas mileage!

Thanks,
91olds98

[diesel1962]

Hello.Are you able to remove the side pan on your transmisson? I think your TCC solonoide is bad.I had one go on an Olds van.Your Olds should be easy to work on as opposed to a minivan. Another thing that may be bad is the speed sensor. Do you know anybody that has a scan tool? Or you can take to an Auto Zone parts store,And they can scan your car for free. Did you try to unplug the solonoide at the transmisson? Did it make any difference? Does the car want to stall when you brake hard?.Let me know what you come up with,Ok? Diesel 1962

[91olds98]

I did some testing, and found that the solenoid is fine, as is the speed sensor. Auto Zone said that the scanner said everything was ok. When I brake hard, the engine doesn't die, and when I over-ride the computer signal and lock the TCC soleniod when the car is in drive, it does not die as it is supposed to (I got that trick from the dealer repair manual )

As for taking the side cover off, yes, its possible to do, but only if I drop the driver side engine/trans mounts off and drop the drivers side of the engine/trans combo down about 7". (Lots of work to do this.)

Also, I did some other digging around, and I believe that the problem is that the transmission fluid pump shaft and the teflon spacer-washers along with the TCC lockup valve have worn down excessively and need to be replaced. Apparently, this isn't to bad of a fix, except that it requires dropping half the engine out (requiring a lift - which I don't have). The other problem is that in order to replace the TCC valve body, (on a 1991, 1992 only) you need a $190.00 reamer tool, which I also don't have. So long story short, I need to get a new transmission, or $1000.00 worth of work done on it if I want the TCC to work again....

...unless, that is, anyone else has any good ideas! In fact, now that I think about it, someone had mentioned once that you could add heavy weight trans fluid and it would solve this problem; has anyone tried this?

Let me know - thanks.