Hi all, my first post as a new member. I really hope I can help others in the future but for now I need a little.
Xj12 1988 GM 400 GEARBOX....There is a cover opposite side to where the speedo cable enters the box. Behind the cover is a spinning thing...Great description I know.
It seems it may be centrifugal. It started clicking as the wheels turn. Does anyone know....
- what is it exactly

?
- should the wings(best word) be spriing loaded
- does oil splash or pump around it therefore should cushion and prevent clicking as each wing falls under gravity as spins? If so, maybe lack of oil due to old filter not getting there? Oil level is good!

 

It’s called a governor. As this thing spins faster, the wings lift outwards, and basically that’s what signals to the transmission to change gear. The should not be spring loaded, just sorta floppy. Changing the weight of them changes shift points in the transmission.

Ever hear the tterm “***** to the walls”? That refers to a similar governor on a steam engine… the governor would spin faster, and the weighted ***** would spin further outward… towards the wall. If the engine is running too fast, it opens a valve and out comes the excess steam.

 

Hi. Thanks for replying. And l love the description with the steam. Best explanation yet.
I've learnt a lot about them over the last 12 hours.
To the point where it is removed and in pieces. You see the issue is, there was zero resistance on the wings. There must have been up until just the other day, as that's when the clicking of the wings falling open could even be heard inside the car.
So I'm trying to work out what gave any resistance so they couldn't just move under gravity. There are the small springs inside the wings if you like, but i' m wondering where any sort of resistance spring could have been. There has to be something as the clicking of the wing falling open, even at crawl speed only began the either day from nowhere.
It's a baffler at this point

 

In case anyone reads this with the same issue.
It's the typical scenario. Look for the simplest thing.
I changed the gearbox filter and oil of course, and what do you know. No more clicking. 😅.
But I learnt a lot on the way.

 

What method did you use to drain the fluids and then replace them? Just took pan off and then filled through dipstick with a funnel or?