I am new to the forum so here goes. I have a 1989 Ford F 150 which the torque converter seems not to unlock. Can someone tell me the symtoms of this and where do I locate the torque converter unlock switch and how can I test it?

 

if the torque converter doesnt unlock it will stall when you come to a stop...everytime...

it will violently shutter as the truck comes to a stop just like if you left it in 4th gear in a manual tranny and just slowed down via the brake without pushing in the clutch...you'll definitely know if the converter is not unlocking

 

Yes, it will stall if it's not unlocking but if it's not unlocking correctly then you will feel and hear bumping when you are moving. One way it is unlocked is by the brake switch. Any time you press the brake it's supposed to unlock and if it doesn't right away then it will bump around until it does.

 

Thank for the info. It sounds like I have an intermittent problem. I drove it today and it seemed to work fine. Sometimes it will bump when accelerating. Normally it will bump when I slow down without applying the brakes. I don`t remeber it ever stalling.Over time it has gotten to the point that at times it does not want to take off. Like the torque converter is not locking up. Eventually it will go, the transmission shifts fine, however, when driving a few miles and stopping,the torque converter smells like it is burning. Any other suggestions.

 

The torque converter only locks when you are in overdrive. It does not lock until it shifts into 4th.

 

Thanks again for the information. Sounds like my problem may be worse than I had hoped for. I was hoping for a simple switch problem. However, since things are slipping on take off sometimes, I assume a transmission rebuild is in order. Are there any other possibilities?

 

have the tranny flushed and new fluid and filter...than drain a quart on your own and add some Lucas tranny additive...that stuff works..

My friends F150 will jump out of gear when it is hot and do weird things...he needs to swap the fluid but the Lucas did help...

 

Thanks,
I will give the flush a try.

 

Thanks for the info guys. I finally decided to spend the bucks to have the transmission flushed. When driving home I had the transmission to bump once. After getting home I removed enough fluid to add the Lucas transmission lubricant. I have only driven about 100 miles in short trips but so far I it seems to be working fine. I certainly do appreciate the forum and the help you guys have given.

 

Could this be a pressure switch problem? I thought you had to have a switch to make the convertor lock up in OD.