66 Buick Electra driveshaft

Discussion in 'Wrenchin' Secrets' started by Jonah Halbert, Mar 24, 2018.

  1. Jonah Halbert

    Jonah Halbert Well-Known Member

    This week I rebuilt my driveshaft. 4 new u joints and a new center bearing. I put it back on the car and drove the car. Theres a huge rattle. I don't know what's causing it. When I get under the car I don't see anything wrong. Does anyone know what could be the issue? The vibration is so bad the car isn't driveable.
     
  2. flynbuick

    flynbuick Super Moderator Staff Member

    Were you careful to get the driveline correctly phased during the re-assembly?
     
  3. Jonah Halbert

    Jonah Halbert Well-Known Member

    What do you mean by phase? Before we disassembled the shaft we used a chisel to mark where each end went. We put it back together the same way. The picture is of before we rebuilt it.
     

    Attached Files:

  4. flynbuick

    flynbuick Super Moderator Staff Member

    No piece was re-assembled 180 degrees from how it came apart?
     
  5. Jonah Halbert

    Jonah Halbert Well-Known Member

    We put it together exactly as it came apart. That's what's confusing me so much. This wasn't a problem before we took the driveshaft out. Now it's a problem.
     
  6. flynbuick

    flynbuick Super Moderator Staff Member

    We have asked another member to drop in to give his opinion.
     
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  7. Jonah Halbert

    Jonah Halbert Well-Known Member

    Ok
     
  8. telriv

    telriv Well-Known Member

    Need a GOOD pic of the WHOLE shaft.
     
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  9. Jonah Halbert

    Jonah Halbert Well-Known Member

    I don't have a pic with the new u joints. The driveshaft is on the car. I'll try to get a picture tomorrow. Heres
     
  10. yachtsmanbill

    yachtsmanbill Well-Known Member

    Just a few quick dumb questions; were all the receiver saddles at least wire brushed clean? That's the yoke on the differential and the frame part of the constant velocity U joint in the middle. How bad was the removal and install of the carrier bearing? Position? Mount? New Rubber isolator?

    Lastly, but pretty important, working under these guys is rough, but you really need to raise the car with a jack under the AXLES, not the frame, to keep the suspension loaded. A differential hanging down on the shocks and springs can change the length and alignment in a hurry.

    How did the U joint install go? If you had to beat on them, there is always the possibility that one or more needle bearings fell out of position. When the shaft is ready to install, all the joints should be a little stiff but free. A lot of that stuff is TIGHT, but needs to go together and not be forced. Snap rings (retainers) all go in as supposed to?

    One more thing is to CLEAN and lightly grease the trans spline (male and female) so that its not forced into position, or have a chunk of old grease/road dirt way down in the bottom of the female side. Check the wear mark where the trans seal rides. ws
     
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  11. dynaflow

    dynaflow shiftless...

    Wild guess...something wrong with rebuild, most likely in the CV joint...
     
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  12. telriv

    telriv Well-Known Member

    Looking again at the pic posted the drive shaft is out of phase. Should be 67 1/2* out of phase. Your u-joints on the front shaft & the CV joint is aligned straight. You need to pull the shaft again. Unscrew the cap securing the front shaft to the splined section. If you look at the inside splines of the front section you should notice there is one spline missing. The external spline on the rear section should have a piece of wire in it that mates with the missing spline in the front section so it can ONLY go on one way. MAYBE??? this piece of wire was removed??? With the wire where it's supposed to be the front section can only go on one way to the rear section. Another thing. If you removed the plug for the greaseable section & left the grease fitting in place this will cause a vibration also. Put the plug back in.


    Tom T.
     
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  13. Jonah Halbert

    Jonah Halbert Well-Known Member

    Everything went fine during rebuild. The CV joint was a bit difficult but we got it. We replaced the rubber bushing and bearing. We replaced all u joints. They all were easy to get installed. We made sure to keep the shaft in phase. We put it together exactly as we took it apart. (But before we took it off the car we didn't have this big vibration problem. The vibration was present but it wasn't so bad to prevent it from being driven.) Also I didn't grease the transmission splines. I will do that.
     
  14. Jonah Halbert

    Jonah Halbert Well-Known Member

    We saw the wire on the splines. We made sure to put it in where there was a spline missing. And the picture is BEFORE we took the shaft apart. This afternoon I will remove the driveshaft again and take a couple pictures and post them here. And I saw the grease plug but did not remove it.
     
  15. Jonah Halbert

    Jonah Halbert Well-Known Member

    Isn't that theven section where the front and rear shafts connect via u joints
     
  16. dynaflow

    dynaflow shiftless...

    Yes. Did you also rebuild the CV...major 2-piece driveline vibration culprit caused by lack of lube. Gets missed a lot, and for not having needle point tip...
     
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  17. Jonah Halbert

    Jonah Halbert Well-Known Member

    I'm not sure what you mean by rebuilt it. We had the entire driveshaft apart and we replaced all u joints. We did put a bit of grease on the ball on the end of the driveshaft which inserts into a cup on the other shaft. The CV joint holds both together; keeping the ball in the cup. Also here's a link to a YouTube video I made of my driveshaft. It's the rebuilt shaft on the car. Watch it and maybe you can see something I dont.
     
  18. yachtsmanbill

    yachtsmanbill Well-Known Member

    Howz about a few million questions?? First off, if yer lucky enough to find another DS, swap it out and check the difference, AS IS. That video looks pretty smooth to me. Was that with the suspension loaded as I mentioned before. Did a chunk of trans mount maybe fall out and the shaft is rubbing on the crossmember? Same with motor mounts and rear suspension stuff. Can you have a pal ride shotgun and video the vibes while you're driving in ALL gears? Find a smooth lonely road and hang the camera underneath at speed. Is it engine speed or load related (coasting or On It?). Governor on the trans have a broken weight pin? Even loose lug nuts. Check allllll the stupid stuff. Pull the hubcaps off too. Muffler hanger bad and rubbing on the CVJ? Busted brake drum? Its been my experience that a DS rumble is usually "harmonic". How bad does the rear view mirror vibrate. Its stupid, but all part of the diagnosis.

    You mentioned the rumble before now its worse, but is it the same rumble? ws
     
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  19. Jonah Halbert

    Jonah Halbert Well-Known Member

    That's what is confusing me. The vibration and thud is only there when the load of the car is on the driveline. The car has to be on the ground and moving for it to happen. Yes the rear axle was on jack stands in the video. But no vibration or thud. The feeling seems to be coming from the first shaft that goes into the trans.
     
  20. dynaflow

    dynaflow shiftless...

    For regular shafts, u-joint rebuild/replace fixes vibration. Two-piece shafts are different. If CV ball/cups worn (lack of lube), shaft will vibrate, especially at low speed. Good practice to kit CV when rebuilding shaft. But, as Bill points out, there can be other causes...symptoms you describe sound like CV, I'd start there...
     
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