A28 4 speed automatic governer pics

[Landseer]

Somebody inquired about transmission governor.

Here are pictures.

I don't fully understand how it works, but this is just for reference for anybody interested.

If you can add a functional description, please have at it.

[MPDano]

That looks like something from the Transformers Movie.

[harborman]

Looks to me like what they used (concept wise) on steam engines to govern speed. Is it possible those are weights which open up as the speed increases and those small tabs then push on the center and move a shaft in or out?

[dtool242]

Originally Posted by harborman

Looks to me like what they used (concept wise) on steam engines to govern speed. Is it possible those are weights which open up as the speed increases and those small tabs then push on the center and move a shaft in or out?

That is correct. As it spins faster, the weights on the fat end swing outward pushing down a rod that goes through the center of the shaft, opening/closing ports as it moves.

Here's mine.


In that picture you can see I pulled off the snap ring and worm gear.



And in that picture you can see that the weights move freely outward and I can see the rod inside the shaft move as I move the weights outward.

There is no obvious problems with the governor, yet I still have issues with low governor pressure and no upshifts. Perhaps some internal passages are clogged, but I don't see any way of disassembling any further.




Perhaps if I press out that split pin near the end of the shaft I'll be able to access the internal passage of the shaft?

Landseer, go ahead and PM me paypal info and I'll buy that spare from you.

[porken]

AFAIK, this is the secondary pump. It's driven by the output shaft so that the 4-speed can be pull-started.

It's deleted on some 722.x trans. I'd like to figure out the parts necessary to remove it.

[dtool242]

The way I understand it (and anyone feel free to correct me if I am wrong) is that the governor is more or less the spedometer for the transmission. Since it is driven directly from the output shaft, the output of the governor should be proportional to the speed of the wheels. If there is a problem with the governor where the pressure is not going up with the speed of the car, then the trans thinks the car is going slower than it is and doesn't upshift.

When I measured the governor pressure, it stayed pretty much constant at a pressure that is equivalent to about 15 mph no matter what speed I was going, hence no upshift from 2nd.