Driveshaft balance prob. on 55 DF car

[Guest]

Just got 3rd member redone, ready to go back in car....when I flipped it over or otherwise made d/shaft rotate, the seal bushing as well as front end, walks around the tube as its spun indicating a seemingly bent d/shaft.<BR> Got all new brgs,seals and side/spider gears as well as a NOS pinion nut. Old brgs were real loose, so didnt notice any wobble in shaft at removal...I can with a little bit of effort...a moderate amt of finger effort, push shaft away from edge to approx. area it should be, I also replaced the front d/shaft bushing as mine was grooved at the seal riding area allowing trans fluid to fill tube.<BR> Do you guys think I should install it as part of the bushing rides in the rear bushing in trans or pull T/tube off and d/shaft and have d/shaft checked for amt. of balance prob. by a shop who does d/shafts????<BR> If anyone has run into this scenario before, let me know as I am almost half afraid to stuff this in and drive away only to discover a helacious vibe from the driveshaft.....Can the shaft be checked for straightness w/o pulling it from pinion spline as this is a royal pain....<P> Your help is immensly appreciated, don55<P><BR> PS, trans is a freshly rebuild w/zero miles...was in rough shape when pulled. I am wondering if d/shaft didnt wipe out the d/shaft front bushing to begin with as clock shows 57K, been parked for about 25yrs....<P> dlw29@hotmail.com

[The Old Guy]

I had the same problem with my 40 when I changed third members. There is a procedure in the book that tell you how to resolve the problem, but it means disassembling the rear end. I solved my dilemma by jamming the rear end under the work bench ,which was attached to the wall ,and using my floor jack to bend the drive shaft. it took 2 0r 3 times to get it running in the middle of the torque tube, but it doesn't vibrate,and I found out the hard way( put it together anddrove it ) thatif it isn't in the middle ,it will shake

[Guest]

Don't worry, a bent driveshaft can actually save you lots of money (IE-shook the gears out of the dash speedo, and that saved my butt from a big big ticket). If it's bent at ALL you'll notice it. Just try it, and don't just go 25 and say "Balanced". Take it up higher. At one point my driveshaft was balanced to around 60mph, anything below was smooth, anything above and it sounded like you were in a 747 taking off, felt about the same too. I just took the old one to a machine shop and they made me a new one balanced to rougly 10,000 rpm I think they said. Anyway, cost me about $100 and hey, I have the comfort of knowing that my Drive shaft aint gonna give out on me anytime soon.<p>[This message has been edited by 67`Skylark (edited 11-28-2000).]

[Guest]

He He He...I used to build 747 as well as triple 7....777 better bird by far...easy to build....noisy....wouldnt you be if you had over 100,000 lbs. of thrust from EACH engine ???<BR> Just food for thought from a 2nd time former employee....I love watching them take off and land though.......Cant do that in a Buick....thats a thought....100,000 lbs. of thrust behind the absolute heaviest Buick ever built....Hold onto your hat and whatever else you hold dear to you....<P> don55

[old-tank]

Hi Don<BR>Take the pinion gear and drive shaft (don't pull the spline) and take it to a drive shaft shop for straightening and balancing. Also be sure there no oil INSIDE the drive shaft since this can happen when the torque tube fills with oil...this can cause a vibration problem also. <BR>Sorry about the extra work...better now than later...seems we all r&r a few times.<BR>good luck<BR>Willie