61 Special Dual Path Tranny Overhaul Issues

**Mecheng** · 01-01-2008, 04:41 PM

Anyone have experience with these trannys? I just completed my first ever automatic transmission overhaul and it still will not go into high gear.
The only bad appearing components were the clutches in the converter which allow it go into high gear. With factory manual in hand I carefully went through the entire transmission with a complete overhaul kit. Still the clutch does not work.

Thanks!

**Dr. Frankenbuick** · 01-01-2008, 05:23 PM

I wish I had experience with that trans as I know you did a lot of work. Could it be a governor or vacuum issue?

**bigirish2** · 01-01-2008, 08:41 PM

I had a 57 that had the twin turbine or whatever it was called. Needed a valve job, so that I did, and when assembled the trans would not shift. Turned out to be a timing issue, that most likely affected the vaccum. Can't remember the details now.
Mike

**Mecheng** · 01-02-2008, 07:44 PM

Thanks for responses. There is no vacumm modulator on the transmission. Shifting is controlled by the governor. It’s a centrifugal actuator not a whole lot different than what is used in split phase electric motors. I triple checked to make sure I had the weights oriented in the right position as they could be easily reversed during assembly. The governor arm contacts a push rod plunger that goes into the 2nd stage governor piston in the valve body. That allows fluid to actuate the clutch pack to lock up the sun gear in the torque convertor for 1 to 1 ratio

There was a huge amount of fine wear debris and clutch particles in the pan when the transmission was first disassembled. I cleaned everything really good with paper towels and kerosene

What I plan to do now is take the valve body off, dissemble and clean thoroughly again with kerosene and blow it out with compressed air.

If that doesn’t work the third thing I will do is relook at the three forward clutch retaining sleeves. These had to removed from the transmission valve body to get at the forward clutch piston to replace seals. Small internal pliers were modified to go 2” deep into the .437 bore and grab the .240 ID sleeve bore to be pulled out. The sleeves transmit fluid from the valve body to several different pistons. Of course one of these pistons applies pressure to the torque converter clutches. It had one of the 2 O ring lands come apart during disassembly but I believe adequately repaired with a thick Loctite silicon RTV material. Problem is I’d have to get one made on the lathe if this turns out to be the cause or find one in junk yard.

Will advise all as progress is made!