C4 auto question?

Well, I see where you coming from; but think you're in the right church, but maybe sitting in the wrong pew.

By moving the shift lever, you are either applying OR releasing the line pressure to the governor valve depending on the position of the manual shift valve. It's either an on or off thing.

You're trying to "shake/thump" the governor valve hydraulically by turning on, or turning off the supply of oil.

Likewise, movement of the flyweight is lateral and depends upon rotation/speed regardless of that shaft's direction. However, by reversing the shaft rotation, the governor valve/flyweight’s “movement” would then be independent of the effects of any oil pressure.

This is a ‘one-time’ hope/attempt at a fix. Trying to “jar it loose”, as it were. :>)

At any rate, the oil never "reverses, flushes or cleans". Ever. It's either flowing to the governor assembly or it's not. And, it is always in the same direction.

Just some early morning trivia. :>)

Allan

I'm not doubtin' you for a minute that you can get 'em unstuck this way. What I'm saying is that it doesn't actually "cure" anything. Just puts it back the way it was just before it stuck in the first place. :>)

They were just prone to sticking because they were made out of aluminum. That bore wears. The "cure" is to replace the governor with a new assembly. :>)

Yeah, you can throw 'em in reverse at 40 mph and it won't hurt a thing. However, it won't apply either.

It's a safety built into the valve body.

Allan

New'ns had their issues,,, Just fiddle fart with it till you won it seamed. This is more so a walk down memory lane to see if I could remember what I would like to forget. I have not been into a automatic in years other than shift/valvebody issues and seal jobs. Split with my partner in 1999,,, he ended up with all the trans parts/tools. I concentrated on the drivability AC end of the business so I got the AC and drivability tools. Even with updated AC/drivability tools its time to replace'em,,,, I look forward to the day when I can say I am not gonna do this much longer and let time pass me by and tinker with old tractors and old tools.

It`s fairly easy to pull the extension housing and clean the governor housing and valve. As the fluid gets older, junk builds up in the gov housing causing the gov valve to stick, not allowing the trans to drop back into a lower gear. A stuck shift valve in the valve body could also do it.

If you don`t want to dig into it, change the fluid and filter, and add 1 bottle of lubeguard. Most transmission shops carry it, I know our local parts stores do also. I`m really fussy about any additive, most of the overhaul in a can stuff is really acidic, and it might soften seals in the short term, but end up doing more damage than good.. Also the zinc in them tarnishes the heck out of anything metal..

After the fluid change he might have to put some miles on it to get her to drop again. If that don`t work, then go after the governor itself. Goodluck BW

However:

Check the TV linkage and return spring all the way from the carb to the center shaft making sure it is adjusted/assembled as it should be. I'm guessing it is plumb okay.

Pull the tailshaft and the little governor assembly off of the output shaft. Watch how you take it apart and don't loose any little pieces/spring. Inspect and clean both weights with a strip of really fine crocus cloth.

If it doesn't move freely (valves drop in the bore via gravity) use some fine grit rubbing compound to polish the governor bore. Lube it with ATF and reassemble.

Now, if the unit is completely wobbled out, gouged, or worn replace the entire assembly. They are just not that expensive.

Any vacumn modulator on any transmission is for "shift feel" only. That's all they do and really don't have a heck of a lot to do with shifting unless the silly hose falls clear off the thing.

Allan

If it is a true C4, they are designed to start out in second with a very, very light load. This will fool ya sometimes.

Are ya sure you don't have a C6?

Allan

I just think in a pickup, it would probably have more of a chance of being a C6.

As I remember it (getting old and the mind is leaving me) the C4 and C5 are hard to tell apart and the differences are mostly strength inside.

Big difference in the C4 pan and the C6 tho.

We've got Brokenwrench on board now; he can give a gospel answer. He does this for a living and he's darned good at giving auto tranny advice.

Allan