51 buick 56r dnyaflow troubles

before I pull the tranny out of my buick is there a external fix for a dnyaflow that has no reverse? it will move forward but not back.finally have 99% of car done and now this raises its ulgy head,lol I tried adjusting shift rod but still no luck,tranny is full,has a hard time going onto park also,thanks

Sorry I don't have an answer

Here's some discussion of late ...

http://forums.aaca.org/f115/dynaflow-transmission-389641.html

Could be, the thrust pad (trans mount) is bad...

http://www.oldbuickparts.com/catalog/up-to-1960-buick-group-transmission-transmission-mount-1948-58-dynaflow-p-6133.html

Sorry I don't have an answer

Here's some discussion of late ...

http://forums.aaca.org/f115/dynaflow-transmission-389641.html

thanks,funny I was looking at that post earlier today.i thought there might be a simple fix rather than going to a lot of trouble taking it out.anybody want an almost finished buick,lol

I have heard that a dislocated reverse strut can sometimes be fixed with the trans in the car. Do you have any manuals that include the trans? I was just looking at the Buick Heritage Site yesterday and noticed that for 56 ( at least) there is a copy of the Dynaflow manual available. Might be worth looking there.

Before trying that I would be interested to know if you ever had it in reverse before? Or is this the first time you have tried it and discovered it was not working? If you successfully had it in reverse before you would know the reverse strut was dislocated by the sound it makes, which is sorta like a gun shot, and then the immediate loss of reverse. Otherwise it could be something else causing the problem. Like a malfunctioning accumulator.

If I was going to try to replace the strut the general scenario requires removal of the pan and the valve body.

I have heard that a dislocated reverse strut can sometimes be fixed with the trans in the car. Do you have any manuals that include the trans? I was just looking at the Buick Heritage Site yesterday and noticed that for 56 ( at least) there is a copy of the Dynaflow manual available. Might be worth looking there.

Before trying that I would be interested to know if you ever had it in reverse before? Or is this the first time you have tried it and discovered it was not working? If you successfully had it in reverse before you would know the reverse strut was dislocated by the sound it makes, which is sorta like a gun shot, and then the immediate loss of reverse. Otherwise it could be something else causing the problem. Like a malfunctioning accumulator.

If I was going to try to replace the strut the general scenario requires removal of the pan and the valve body.

I agree with the reverse strut. Easiest way of seeing if that is the problem is to remove pan and valve body. Then reach up to reverse band and see if it is very loose and wobbly. The strut should be where you can get to it. (Pretty sure it is adjacent to the reverse band adjusting screw.) The other side of the band is for the servo linkage.:cool:

There is both a transmission mount and a thrust pad at the rear of the Dynaflow at the torque ball. Usually if one is bad, so is the other. The rubber part separates from the steel mounting brackets.

Good luck.

Joe, BCA 33493

There is both a transmission mount and a thrust pad at the rear of the Dynaflow at the torque ball. Usually if one is bad, so is the other. The rubber part separates from the steel mounting brackets.

Good luck.

Joe, BCA 33493

Thanks for that. I was confused by that

thanks for info.,i never did drive this car when I got it,it had sat for 41 yrs. in a dirt floor building.when I got it running it ran like grap so I rebuilt or replaced everything on motor,runs great now.i had it on stands and put it in gear and wheels turned.next I put it in reverse and wheels turned but not backwards.also when it is in park and you rev it up it will pop in gear.almost ran me over once.i looked at buick manual and it shows what you mentioned,will drop pan and see if rod came loose or broke.thanks again will keep you informed on progress

Jumping out of park sounds like trans mounts (Like Joe said, there is a thrust pad and trans mount) AND / OR linkage. Both of which are adjusted with the trans in the car. That is where I would start.

found problem with no reverse.took pan down and looked up at shift lever and the upper lever was broken from the lower rod that moves valve in and out.removed valve body and found shift valve frozen whitch caused lever to break.rewelded and cleaned everything up and now have reverse. thanks for all input.ps:thrust pad was also shot as was trany mount.

NOW you can DRIVE it to Springfield!

Ben

I don't think I have enough trust in it yet,lol I think I will do some short drives and work out all the little things that keep coming up.

You got six weeks. There are a lot of Texans going.