Stall test results

[Richard Player]

I did a stall speed test today on my 94 taurus. The specs say the tachmeter should read 1791-2097 for a v6 with a 3.8L engine. The readings I received were 1570 in drive and 1540 in reverse. The manual gives a diagnosis if the stall speed is over specification.
What does a stall speed under specification indicate?
When they call it a stall speed test I would assume the car should stall. The car did not stall ?

[TaurusKing]

I rhink stall speed has something to do with the torque converter transferring engine power to the transmission. be careful doing things like the old brake-rev test, not saying you are, but damage can result if done too long.

[shorod]

Welcome to the forum!

Just out of curiosity, why are you performing a test that you don't understand what it's for, and how did you get results from your car if you don't understand what the results are supposed to be?

I'm not a transmission guru, but I believe the stall speed is the speed at which the torque converter starts to apply power to the transmission. There's probably some cutoff, like 80% of the engine power is transferred to the transmission. I'm quite sure it's not the engine speed at which the engine will stall.

Either way, this test is pretty hard on the transmission and will heat up good fluid and possibly cause glazing of clutches with bad/old fluid. Not something I'd be trying just out of curiosity.

-Rod

[Richard Player]

Thanks for the replys. The reason I had the stall speed test done was because the line pressure test indicated that the pressure was 220psi and front hub seal on the torque converter leaks. If I replace the seal then while the transmission is out of the car it would be sensible to replace the cluches if they are worn. There is low milage on the car so I don't suspect the bearings, thrush washers or bushings will be worn to any degree.
I hope there hasn't been damage done by doing the test.

A second question would be how badly does the seal have to leak before it should be replaced?