Hydramatic Jet-Away stuck in 2nd gear???

[Larry Reeves]

Anyone else have this happen? One day, it just wouldn't shift into 3rd or 4th... I suspect a stuck valve internally, but anyone know better? Only 2k or so on a rebuild 3 years ago...

[Glen]

What year car is this in? 

Glen

[Jesus Wept]

It is in a 1961 Commercial Chassis Hearse.

By the way, sorry about the name, but I am having trouble signing in...

[Larry Reeves]

Again, sorry about the name... On the bright side, I found my password...

This has happened once before. I tried to drive it from North of Dallas to Texas Stadium in Irving (20 miles or so) in 2nd gear. Believe me I didn't want to, but I had a MAJOR appearance at the Cowboy's halftime show that could not be missed. While on the way, about 10 miles into the slow trip, it suddenly shifted into 3rd then 4th, and continued to function properly for about a year until it failed again this last time. THIS is why I think it may be a stuck valve and not a broken part...

[Glen]

Looking at the ’61 shop manual it says the rear unit fails to go to direct drive and remains in reduction.  This can be caused by:
1)   G2 governor valve stuck closed.
2)   2-3 shift valve stuck closed.
3)   No. 1 governor ring broken.
4)   G2 passage through reverse piston cover to shift valve body obstructed.
5)   Less than correct number of rear clutch plates.
6)   Rear clutch apply oil leaking internally.
7)   Rear clutch mechanical apply failure.

Then it goes on to say:
With the car on jack, check mainline pressure at 30 MPH with the TV rod disconnected.  Line drop pressure of 65 lbs. indicates item 2, 5, 6, or g.  Normal line pressure, 95 lbs. indicates 1, 3 or 4. 

The G2 valve is in the governor inside the tail shaft housing, so 1) and 3) require removal of the tail shaft housing.  Number 2) is the easiest as you only need to remove the pan and valve body.  Number 5) is not very likely, so that one can be eliminated.  Number 4) while possible requires some research to figure out witch passage that is.  Numbers 6) and 7) require the removal of the transmission. 

It looks like the next step is to drop the pan and shift valve body for cleaning.  It is very important that you put the valves and springs back exactly as they come out of the valve body.  Turn one around and the transmission won’t work at all.  Also putting the wrong spring in will really mess things up.  The best procedure when working on the valve bodies is to remove the parts from one cylinder at a time.  Put the parts in order and with the proper orientation (front to back) in a grooved holder so they don’t roll around and can be kept in order. 

Cleanliness is of utmost importance here.  One small bit of dirt can cause problems like you are having. 

Be sure to clean the pan and change the fluid if it looks slightly dirty. 

Glen