automatic transmission will intermittently disconnect from the drivetrain?? HELP!!

[arnel619]

I have a '93 4runner SR5 with 157,000+ miles. The automatic transmission will intermittently disconnect from the drivetrain, as if I were putting it on neutral. At the same time the speedometer goes to zero while I am coasting. Usually stopping and putting it into 4wd will correct the problem, and then It goes away sometimes for months at a time. Has anyone had a similar experience? And if so what was the fix? Any help would be appreciated.

~Arnel

 

[hubbabubba]

It sounds like a problem with the torque converter. Might want to take it to a transmission shop.

 

[SteveM]

The speedo goes to zero and you're still moving??

Maybe it's an electronic problem where the computer thinks you have stopped moving (due to zero speedo readout) and unlocks the torque converter.

Best to take it to a shop for a real diagnosis.

 

[arnel619]

Thanks for the posts guys.

I have actually taken it to the Toyota dealership and they can't seem to re-create the problem everytime I bring it in. Another thing I wanted to mention was that the spedometer does go out from time to time without the transmission going into neutral. The workaround for both problems for now is to slow down (1-5 mph) and shift to 4wd then shift back to 2wd.

I thought the spedometer problem was due to the spedo cable but that does not explain why it turns back on when I shift to 4wd then back to 2wd.

 

[TSP-MIKE]

It's your transfer case crapping out. Could be your transfer case valve body getting stuck, or not enough line pressure for the transfer case.

Mike