Erratic Lock & Unlock @ 45 mph

[Outpost]

The converter in our '87 T (see sig) has begun to lock and unlock erratically at around 45 mph. As road speed increases, the converter locks and remains locked as it should. I believe a similar problem occured before we purchased the car and the previous owner replaced the torque converter only to discover that a 'shaft seal' was leaking and causing the problem. The converter was replaced anyway, so I'm inclined to think that the converter itself is not the problem.
Does this sound like a 'shaft seal' problem? If so, how involved is the repair?

 

[6PacktoGo]

Rick,
It ain't likely to be the o-ring on the input shaft. What you're describing sounds a lot like a vehicle speed sensor problem, it is at least most likely an electronic problem and not mechanical or hydraulic. It is possible that the o-ring is leaking, but they most often last longer than the transmission and converter. If it has failed, there is something else seriously wrong. You have to pull the transmission, pull the converter, and replace the little o-ring on the input shaft, _IF_ it has failed.

 

[WE4]

I would suggest you listen to the guy above........



Bruce
WE4

 

[Outpost]

I always listen to that guy...Thanks, Alan.

 

[TurboBob]

flaky third or 4th gear switches can cause this also.



TB

 

[MeanBuicks]

Install a TCC switch in the ALDL and when the car starts acting up, activate the switch (which directly grounds the circuit). If the TCC continues to act up, the problem lies in the transmission/converter.

If the TCC straightens out, then you have a control problem ie.; VSS, ECM, pressure switches, etc.