Hello all,

I have a low speed clicking sound audible from inside the car at speeds below 25mph, the frequency of which is proportionate to vehicle speed.

With the assistance of a helper rocking one of the rear wheels back and forth I’ve isolated this sound to the back of the transmission. Extra scrutiny was paid to the driveshaft UJ and I am fairly sure we are all good there.

It seems to me to be coming from behind what I believe to be the governor assembly cover on the side of the transmission. From parts diagrams there appears to be a plastic gear in the assembly which could be a prime suspect but I will admit that my understanding of this assembly, and transmissions in general, is quite limited.

Any information or opinions regarding this would be greatly appreciated.

 

If you rotate the driveshaft with the engine off, you can here the governor weights "click" as they fall to the bottom during rotation. I've never noticed this with the engine running and in a forward gear as I would think hydraulic pressure would prevent this. As far as the gear goes, they seldom fail in a TH400 and I don't think they would make any noise even if it was missing a few teeth. If you have any doubts, simple to remove the governor and have a look. With the car a little downhill you won't lose any oil.

 

Thanks,

I educated myself on the governor and subsequently pulled a spare out of my parts car’s transmission. Sure enough, as you say, the sound of the weights falling as it rotates seems to be what I’m hearing as I rotate the driveshaft.

The question now is why I can still hear them at low speeds in forward/reverse. The transmission is otherwise functioning normally. I’ve ordered a gasket for the cover and once it arrives I’ll take a look and report back. I’ve now got the spare governor just in case.