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700r4 accumulator question

12K views 2 replies 2 participants last post by  oldchevy1956 
#1 ·
I have a 700r4 trans that all in all works fine. My question is I have a very hard 1 to 2 shift especially at slower speeds. I have read other articles on this site about this and I found that I may need to check my 1-2 accumulator. So after disassembly I found that a previous owner has put a spacer on the piston rod between the accumulator housing and the 1-2 accumulator piston leaving the 1-2 accumulator spring although the piston can't seem to move. The 3-4 accumulator has a similar setup but the 3-4 shift is fine. This trans has a corvette servo in because I put that in last week. The 1-2 shift was firm before and after the servo install.

Now, to lighten up the 1-2 shift do I take the spacer out of the 1-2 accumulator? Do I leave the spacer in the 3-4 accumulator? I realize lightening up the 1-2 shift will cause more clutch slippage but my neck will feel better.

Another observation about the TV control valve is when I remove the TV cable and lightly push the valve against the spring only 4 rings are present on the valve tip. I am not sure if more should be present of course that would take a longer spring on the other side of the valve. So is 4 rings good or too many or most likely too few?

Please advise me.
 
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#2 ·
700r4

When the accumulator piston can't move, because it is blocked, your transmission will lose the ability to cushion the 1-2 upshift.

Install the accumulator piston then the spring and remove the spacer, so that the piston can travel and absorb the shock.

Your call on the 3-4 accumulator. Although I like accumulator action, to mitagate the "shift shock".

As far as the TV plunger spring goes, I don't see a problem with what you have,[4rings]
 
#3 ·
700r4 accumulator

I took the spacer out of the 1-2 accumulator and now it works great. Smooth firm 1-2 shifts but not the neck breaking shift it was. I also cut the spacer in half (now only about 3/8 inch) and installed a spring on the 3-4 accumulator so that it would have some travel and it works about the same as before which was a good solid 3 to 4 shift, so all is good. Thanks for the info.
 
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