727 help

[mally69]

ok  has anyone had any balancing trouble with  a b/m holeshot 3000 stall torque convertor? well the reason i ask is because as im driving down the road there is a vibration( not the engine already checked all u joints and driveshaft and tires) also i put in a new slip yoke still i have a vibration any idea of what this is ??

also i know that the 727 tranny doesnt not pump when it is in park, well when i take it out of park then  put it gear it still slips for awhile until it pumps up        when i  sit there and rev it up in nuetral for about 10 seconds then put it in gear it goes fine     ( should it take this long just to pump up ??)  i also have a b/m shift improvment kit

[Ghoste]

My converter takes that long to fill when it's been sitting.  As for the vibration, that's a tricky dragon to slay.  Check all your trans mounts and engine mounts, wheel balance weights still on and block tight to trans.  Check pinion angle.

[chargerbr549]

On your converter pump up issue, the 727 and 904 trannies don't circulate fluid in park, only in neutral, so I automatically put my tranny in neutral for a little bit to pump up the converter before I put it in gear, I remember that in some of the Gil Younger shift improver kits they have  a different "manual valve" that will circulate fluid to the converter when in park, if you so desire. The valve body has an "anti-drainback valve" that is suppose to keep the fluid from the converter from draining back into the pan but they generally don't do that job very well and it seems on higher stall coverters they are way more prone to taking longer to move the car as compared to a stock converter after having sat for awhile.

Kevin

[74Charger]

I might be wrong.  But when I just changed out my convertor.  The one I had in there had a weight on the convertor.  I was told that If your engine is externally balanced that you have to have a weight on the convertor.  If your engine is internally balanced you dont need the weight. 

My engine seemed to have a slight vibration to it.  I knocked off the weight and it was a lot smoother.

[John_Kunkel]

Unlike many other brands, there is no "anti-drainback valve" in a Torqueflite, converter drainback (often called "morning sickness") is a perfectly normal occurance.

Starting in Neutral or installing the aftermarket manual valve are the solutions for "morning sickness"

[69chargeryeehaa]

alot of vibes comes from tires, one other thing you can try is to rotate the driveshaft 180* deg in the rear u-joint and see if that makes a difference.  or did you just change the converter and got the viberations?   

[deputycrawford]

run the car just past its vibration point. Throw it in neutral and let it coast back down below the vibration point. If it does the same thing then its a drive line issue. If it only vibrates under load, I would go back to your converter. Like 69chargeryeeha asked, did it start just after you put in the converter?

[mally69]

well i dont know becuase we put the whole car together then drove it and had this vibration     i just got called to go to work so ill be away untill friday this week  i will when i get back drive it and try putting it into nuetral and see if the vibration is stil there

[69chargeryeehaa]

well i'd say if you just put the car together, try rotating the tires, from side to side or front to back depending on your setup.  90% of vibrations are due to tires, i've had cars where they were balanced over and over and still had a vibe, change the tires and the vibes are gone.  also a quick easy thing to try would be like i suggested before is to unbolt the ujoint in the rear of the drive shaft and rotate it 180*deg and bolt it back.  at least the vibe will stay the same, or happen at different speeds.  that will tell you what to look at next.  also another thing could be a dirty hub, where the tire is'nt completely true sitting on the rim, if they are not perfectly clean i've had that cause a nice vibe as well.  those are the simple things to check.  you could also jack up both rear tires and run the car in drive at idle and look at the tires and make sure they are not out of round.  maybe also check and adjust the front wheel bearings preload, i've had that cause a vibe as well.  vibrations are really fun to diagnose, but those tests at least help you isolate the problem, if there is no change at all on each test then you can focus on the driveline.  the netural driving test is good, but only really tells you if the vibe is comming from the tranny or TC assuming the tires, drive shaft, bearings ect.... are all ok, and since in netural the rear end and drive shaft is spinning it really does'nt tell you much cause if the tires are out of round you'll still have the vibration.  make one change at a time and then do a road test, pay attention to the vibe and what speed it occurs and see if any of those tests makes any change at all, like different speeds ect....good luck

[deputycrawford]

I have a vibration right now also. I have put other rims and tires on and it is still there. I have had the pig apart twice and everything measures ok. I changed the drive shaft, and went to the 1350 yolks, and its still there. It seems to vibrate from slight load to heavy load. It goes away at speed when I dump it into neutral. It has done it with two different tranny's and converters too. Im totally lost on my problem. Would an engine balancer going out cause the probelm?

[69chargeryeehaa]

I have a vibration right now also. I have put other rims and tires on and it is still there. I have had the pig apart twice and everything measures ok. I changed the drive shaft, and went to the 1350 yolks, and its still there. It seems to vibrate from slight load to heavy load. It goes away at speed when I dump it into neutral. It has done it with two different tranny's and converters too. Im totally lost on my problem. Would an engine balancer going out cause the probelm?

i would think that the engine balancer is only for the crank balancing, and if that were bad your motor would'nt last too long lol.  if i were you i would look at the "constant" here, which is only the rear end, bad bearings, ring/pinion, bent axle would be my guess, since you've had the pig out, ect...process of ellimination!!!