If I am coasting, and have the throttle partway down, not enough to provide any propulsion, but just a little gas, the car makes a wierd grinding noise. Also, the car jerks when moving from a rolling stop. If I slow to 2-3 mph then hit the gas, the car jerks into motion.

Scott

 

Transmission shudder?

What ATF are you running? For the SC400 it should only be Toyota T-IV.

 

Well I have done 2 drain and refils using genuine T-IV since I bought the car, but I don't know what was/is still in there. I know the previous owner was using some sort of additive. When I first bought the car, it would make a grinding noise when downshifting at low rpms, but that was fixed after the first drain and refil.

Scott

 

Any more thoughts? Would transmission shudder also cause the grinding-type noise? It occurs at all speeds, on level ground with part-throttle. The car does shudder when letting off the gas. Would my problems most likely be related to the transmission, torque converter, differential, or something else? Any and all input is appreciated.

Scott