Subject line says it all. I have trouble with the lock up clutch on my 91 940 with AW71L when it gets up to operating temperature. When the trans is hot the lock up clutch refuses to engage unless I apply more throttle. Obviously, this means the car continues to gradually accelerate over the speed limit. When I back it off to cruise the clutch unlocks. This isn't good for fuel economy. When the trans is cold (or in the process of warming up) the lock up clutch works perfectly. Only when it gets hot does it play up. I'm the one who serviced the valve body recently in the hope of fixing this problem. I thought it had worked but it had been relatively cool during that time so chances are the trans wasn't getting up to full operating temperature. My understanding is that the lock up clutch is inside the torque converter. Could it be the problem? Are there any trans gurus here who could advise? The trans itself shifts through all the gear perfectly fine. I can't go on long drives because of this problem.
Any advice???????
Thanks
Brad