Hard 1-2 Shift on my '57 Hydramatic

[Dave Burke]

Hi Y'all,

When I got my '57 SDV, I started poring over the engine and how the previous mechanic had things set up.  I noticed, for instance, that the TV rod was run all of the way forward.  This meant that I think that I had a 3-speed rather than a 4-speed transmission.  I re-set it to factory manual specs and voila!  I had an extra gear.  BUT it shifts funny from 1st to 2nd speed.  It isn't smooth, like 2-3 and 3-4.  The engine revs high, then it acts as if the clutch remains engaged longer than it should, and then it "thunks" into 2nd, and afterward it runs smoothly.  Now I have studied the manual and I understand the basic principle of the Hydramatic transmission.  I also looked at the troubleshooting guide and think that I have a solution, but as that solution will involve draining the system, pulling the tranny pan, and dropping the valve assembly, I figured that the prudent thing would be to ask if any of Y'all had faced the same thing, and what was done about it.  It could also be that I need to adjust it some more at the TV rod, but I figure that I paid for 4 speeds and I want 4 speeds!

Thanks in advance,

Dave Burke
CLC# 27968

[Walter Youshock]

You still need to play with the TV rod.  The factory setting will get you close but not always spot-on.  Usually, the 2-3 shift is rough.  The rough shift may change once you start fiddling with it. 

[Dave Burke]

Hi Walter,

Will do, but I wonder if there might be a bit of crud in the valve assembly - that was why I was thinking of pulling it and giving it a good cleaning.  I'll fiddle with the rod first - less getting under the car that way!

Dave

[Walter Youshock]

If the trans was never worked on, I would definitely suspect yuk in there.  I swear by SeaFoam products.  They have one for transmissions but what you describe leads me to TV rod.  The 1-2 shift is fast and barely perceptible.  What you describe is classic 2-3 shift BANG.  I just had mine totally rebuilt for the third time and it will still act that way under load climbing steep hills.  Straightaway, it's perfect.

[Dave Burke]

I'll look at it, and I have added the Sea Foam to the transmission so I'll see if I can't work it out via the TV rod.  If not, I have a new tranny pan gasket coming and I'll drop the pan and valve assembly and see if I can work it out.  Boy, if it ain't one thing...

Dave

[Roger Zimmermann]

Dave, the 1-2 should be as smooth as 3-4 as the upshift is done by filling up the front unit coupling. A dirty valve body could be the cause of malfunction.

[Dave Burke]

Hi Roger,

That is exactly my thinking.  When I finally got my head around how you get 4 speeds out of an automatic tranny without a whole gallery of gears (I am far more familiar with motorcycle gearboxes and manual transmissions), and that basically there are two hydraulically-switched systems that are either direct-drive or hydraulically coupled (like an "on-off" switch if you will), I realized that a sticky valve might be at the root of things. 

At the same time, Walter's approach is appealing because it means avoiding a bath in tranny fluid!  What I suspect is that the previous owner's mechanic was faced with the problem and figured that since 1st gear is at such a low ratio, that it would do no harm to run the TV rod all the way forward and bypass it for the most part.  One of the things that I noticed when I readjusted the TV rod was that I began to get engine braking, which I did not have before.  All of the braking was on the brakes themselves.  Now the car downshifts like it should.  I surmise that the 1-2 valve was sticky and rather than fix it, he just adjusted around it.  This is not surprising as I have found other examples of this as well.  So I will probably end up taking the bath just to satisfy myself that all is well, and if not, a bit of polishing with a Q-tip and some Simichrome or some #0000 steel wool might do the trick!

Best,

Dave

[Roger Zimmermann]

Dave, it's not the first time the TV rod is adjusted that way. I had a French customer who had a major engine damage because the transmission never went in 4th. As he was not especially automotive oriented, he took that behavior as normal. Driving at 75 to 80 MPH for a long time in third gear is definitively no good. His transmission went bad too...

The oil pan has a drain plug, so the oil bath may not be that bad!

[Dave Burke]

Roger, I have already dropped the pan once.  It WILL be bad!  I will be soaked.  But it is worth being a grease-coated ape if she runs true and proper.  And I admit: I am SCARED of working on an automatic transmission because they function on principles of magic and the arcane.  I feel like a lab rabbit who is confronted with a ticking hydrogen bomb.  But then I watch a John Wayne movie and roll up my sleeves, grab the toolbox, and start pulling things off of the car.  When I did the tranny pan I was amazed that A) there was so little sediment and crud in it, and B) I correctly applied the gasket to the point where it did not leak a drop!  The next step of course is to pull the valve bod off, and this is daunting because I can only imagine a "poing!" sound and a zillion ball bearings, tiny springs and valve guts go shooting across the carport, never to be seen or heard from again.

I reckon that it is time for another John Wayne movie.  Maybe "The Quiet Man" (Maureen O'Hara - zowie!). 


Dave Burke

[Roger Zimmermann]

There is amost no risk by droping the valve body. Just look how it's installed, especially the manual valve: it must engage in a pin. I believe the 1957 valve body has one ball (the shop manual is telling it), but you need further dissassembly to get at it.
The valve body is an assembly of 3 small valve bodies. When I do a transmision, I remove and clean one valve body after the other. You must be careful with the springs and the way the valves are inserted into their respective bores. Take your time, it's not science rocket, just look how it was before...
I can assist if needed; just the distance is a problem!

[Dave Burke]

Thanks Roger,

I'm not all that worried really, and my car may not have the ball as it is a mid to late production SDV - still I plan on being careful!  I also hope that it quits raining soon because I need to grind my tranny dipstick where I welded it together.

Then again, maybe this ain't that kind of forum...

Best,

Dave

[Viator Trudeau]

Hello all,, I have drained many auto trans. W/O drain plugs.
The fill level on most trans. is apx. an inch or two above the pan gasket.
The night before I would put a 1/4" or 3/8"tube down the fill tube to touch the bottom of the pan to  start to sip on the oil out as much as possible, W/ only an inch left in the pan by the next morning.
  Run the tube down to the bottom on the drain pan either over the finder or straight down into the pan.  The next A.M the oil level will be much below the parting line of the pan. With a little care you will not spill any oil.
V. Trudeau  #8697

[Dave Burke]

Ah yes, the old siphon method!  I am fortunate to have the drain plug though!

Dave