cruise o matic help?

[milldinaire]

My buds Cruise o matic has no power in first through third gears, but has full power to reverse. This situation happened out of the blue heading up the street. Kick down is not engaged and holds vacuum pressure to the modulator. Never had shift issues. Just curious if this might be serious or a simple fix?

[milldinaire]

This is in a 1966 slick.

[BarnieTrk]

You didn't say anything about them, so we need to start with the simple & obvious questions:

I'll assume your Buds '66 COM is bone stock. Has it ever had service work, if so what was done and how many miles/days ago?

Has your Bud done the basics - change the ATF in the last two years, has he ensured it's at the correct ATF fluid level now?

From what little you've said, the symptoms sound like to me that he's got an old tranny with some sludge/crud plugging up some internal passages, preventing the Automatic Transmission Fluid (ATF) from getting to where it needs to go.

The first thing I'd suggest is getting the trans up to operating temp and then dumping the ATF fluid, clean out the inside of the pan, install a new fluid filter & gasket and refill it with fresh Mercon. Once that is done and he's ran it 50 miles, what is it doing?

BarnieTrk

[unibody madness]

Sounds like a good place to start!
The truck was supposed to be a one owner truck out of Mariposa Ca. bought from the estate of a Possey high school teacher, by a former student, who wanted to restore it for one of his twin sons.
I picked it up in a deal I made for the Turk, after garage repairs had been done on the 352 to stem oil leaks. It appears to be bone stock, other than the smog equipment of the day having been removed
My son drove it to northern California, where he used it sparingly ( under 1000 miles), as alternate transportation,for the next 10 years.
There were no records available when I bought it.
Milldinaire has been spending a lot of time getting it road worthy for the member I sold it to and the tranny just cut loose with no warning.

[Lowell]

Torque converter?

[bruceandersson]

Either the trans needs a rebuild or it is low on fluid. Check fluid level warm, running and in park.

[Lowell]

The reason i said torque converter i had a 57 Studebaker that used same tranny as a ford . The stater went bad (its on a one way clutch)in the converter and it didnt hardly have power to get moving. once did get up to speed it seemed normal.

[bruceandersson]

I think we need to know what no power in 1-3 means. Does it work, but appear to slip or does it not go anywhere? I assumed it was not going anywhere. Often low fluid will work in reverse but not in any forward gears. Old transmission guy told me once that there is more pressure applied to the reverse circuit.

[Toyz]

Reverse does require considerable more pressure than forward gears; thus, you can pretty well rule out crud, etc., as the current problem. That leaves the one common major part involved in all forward gears, the forward clutch. Naturally, competent diagnosis involves the full range of pressure and adjustment checks. Most people with strong experience in the old COM's are going to immediately suspect the forward clutch in the described situation. Largest problem may well be locating a mechanic experienced in these relics! It is a rather straight-forward trans, but just like any other repair, experience often makes the difference; if not the first time, then certainly with any following issues.
Paul

[yellodog]

drop the pan, you'll probably find your answer there.