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Curious Vibration While Coasting

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    #16
    Slip yoke splines need no grease, they will flood with transmission fluid quickly enough after you fire up the engine.

    Yes do use some grease on the seal between the two lips, really doesn't matter what kind it is as it's there just to make things slippery and all grease dissolves into transmission fluid eventually anyways.
    The ones who accomplish true greatness, are the foolish who keep pressing onward.
    The ones who accomplish nothing, are the wise who know when to quit.

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      #17
      Just don't go nuts with the grease. You only need enough there to keep it slippery until a bit of trans oil works its way in there to keep it moving.
      86 Lincoln Town Car (Galactica).
      5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley

      91 Lincoln Mark VII LSC grandpa spec white and cranberry

      1984 Lincoln Continental TurboDiesel - rolls coal

      Originally posted by phayzer5
      I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousers

      Comment


        #18
        I pulled the driveshaft last Friday and the U-joints seemed fine enough. They all had a full range of smooth movement with no hint of binding etc. There was at least one axis on one U-joint that had noticeably freer movement than others (I didn't keep track, but I'm pretty sure it was on the front end), but there wasn't any slop in it. My drive afterwards felt pretty much the same as after the problem largely corrected itself. By "largely" I mean I think I can detect a very brief and small amount of the curious vibration during transitions between powered and coasting movement, but I might be imagining things.

        Just before the problem largely corrected itself, my car had been sitting for many days, and the battery had been disconnected for some of those days (as a result of going to check my plugs and change boots before deciding to put it off until I do the tensioner stuff). I can’t imagine that there’s a computer aspect to the curious vibration, but I’m far from being an expert.

        FWIW, I don’t know how the pry bar on the diff end of the driveshaft trick is supposed to work, but what I ended up doing is putting two pry bars back to back so they served as each other’s fulcrum and then squeezed them together. It worked like a charm.

        2000 Grand Marquis LS HPP, a hand-me-down in 2008 with 128,000 km; 175,000 km as of July 2014
        mods: air filter box 'tuba', headlight relay harness, J-mod (around 186,350 km), 70mm throttle body, KYB Gas-A-Just shocks, aluminum driveshaft, ARA3 PCM

        Comment


          #19
          Originally posted by IPreferDIY View Post
          FWIW, I don’t know how the pry bar on the diff end of the driveshaft trick is supposed to work, but what I ended up doing is putting two pry bars back to back so they served as each other’s fulcrum and then squeezed them together. It worked like a charm.
          WTF are you talking about? Xplain yoself pleez!
          The ones who accomplish true greatness, are the foolish who keep pressing onward.
          The ones who accomplish nothing, are the wise who know when to quit.

          Comment


            #20
            I just picked a random photo from the internet (apparently from another type of car, ignore the arrows) to show the square slot (seen at the bottom) where people say to use a pry bar:

            Click image for larger version

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            I used two pry bars:

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            Last edited by IPreferDIY; 11-21-2016, 10:18 PM.

            2000 Grand Marquis LS HPP, a hand-me-down in 2008 with 128,000 km; 175,000 km as of July 2014
            mods: air filter box 'tuba', headlight relay harness, J-mod (around 186,350 km), 70mm throttle body, KYB Gas-A-Just shocks, aluminum driveshaft, ARA3 PCM

            Comment


              #21
              Oh THAT, to pop the yoke off the companion flange. Yeah that don't really work when there's good amount of rust involved, somewhat more violent measures need taken to make things separate then But typically a few good whacks with a dead-blow hammer or even a rubber mallet is enough even with mild case of rust and is obviously pretty safe, whereas your trick with the two prybars can be quite dangerous if something slips. Just keep that in mind for next time you gotta work on something like that.
              The ones who accomplish true greatness, are the foolish who keep pressing onward.
              The ones who accomplish nothing, are the wise who know when to quit.

              Comment


                #22
                In my case, I was laying on the ground and just used my abdomen to catch it. It didn't really take much (after some light tapping didn't work), and that was the big surprise for me. I cleaned and oiled the mating surfaces, so hopefully it won't be an issue next time. I suppose a good precaution for stubborn ones would be to put loose zip ties through the bolt holes so the yolk doesn't have anywhere to go when it pops free.

                2000 Grand Marquis LS HPP, a hand-me-down in 2008 with 128,000 km; 175,000 km as of July 2014
                mods: air filter box 'tuba', headlight relay harness, J-mod (around 186,350 km), 70mm throttle body, KYB Gas-A-Just shocks, aluminum driveshaft, ARA3 PCM

                Comment


                  #23
                  How do the needle bearings in the U-joints work? Do they engage in a constant rotation when the yoke spins, or is it just a back and forth motion like a throttle plate bearing?

                  Edit: Here's a neat video:



                  My impression is the pair for the left shaft in the video might just go back and forth but the pair for the right shaft in the video might have a constant rotation in one direction. I can't quite visualize the latter.

                  My impression for my issue is that there's a transition zone from driven to coasting, and that the vibration occurs as a result of some slippage in the transition zone. I'm not sure if that actually makes sense in terms of how the needle bearings are supposed to respond.
                  Last edited by IPreferDIY; 02-15-2017, 02:02 PM.

                  2000 Grand Marquis LS HPP, a hand-me-down in 2008 with 128,000 km; 175,000 km as of July 2014
                  mods: air filter box 'tuba', headlight relay harness, J-mod (around 186,350 km), 70mm throttle body, KYB Gas-A-Just shocks, aluminum driveshaft, ARA3 PCM

                  Comment


                    #24
                    They do whatever they feel like doing - change the grease consistency even and you change their behavior. You're overthinking this, if they got play replace the fuckers, use a quality U-joint - tight U-joints make no clunking noise, and I've had high-mileage factory Spicers move nicer than brand new Moogs. That said do keep in mind the 8.8 axle is one of the loosest ones out there as far as gear mesh goes, for example a Dana 60 (front or rear doesn't matter) calls for 4-9 thou backlash whereas the 8.8 wants 11-16 thou (yes I know the numbers by heart, lol), a 5-thou Dana will always be quiet whereas a 15-thou 8.8 is one hell of a clunking mother! The right gear man will make your axle do pretty much what you want it to do, but you'll pay for it (last one that needed special attention took me a whole night). Keep in mind that a noise-maker most people won't think of can be the axle shafts sliding in-out excessively, that was what that all-nighter was all about actually.
                    The ones who accomplish true greatness, are the foolish who keep pressing onward.
                    The ones who accomplish nothing, are the wise who know when to quit.

                    Comment


                      #25
                      I watched Eric The Car Guy rebuild an 8.8 and said F that. You guys that have the patience for that, good on ya.
                      1985 LTD Crown Victoria - SOLD
                      1988 Town Car Signature - Current Party Barge

                      Comment


                        #26
                        Originally posted by His Royal Ghostliness View Post
                        They do whatever they feel like doing - change the grease consistency even and you change their behavior. You're overthinking this, if they got play replace the fuckers, use a quality U-joint - tight U-joints make no clunking noise, and I've had high-mileage factory Spicers move nicer than brand new Moogs. That said do keep in mind the 8.8 axle is one of the loosest ones out there as far as gear mesh goes, for example a Dana 60 (front or rear doesn't matter) calls for 4-9 thou backlash whereas the 8.8 wants 11-16 thou (yes I know the numbers by heart, lol), a 5-thou Dana will always be quiet whereas a 15-thou 8.8 is one hell of a clunking mother! The right gear man will make your axle do pretty much what you want it to do, but you'll pay for it (last one that needed special attention took me a whole night). Keep in mind that a noise-maker most people won't think of can be the axle shafts sliding in-out excessively, that was what that all-nighter was all about actually.
                        My '97 has a lot of backlash. At least I think thats its issue. Get the typical clunk when going from coasting to not coasting that originally I thought was u-oints till I changed them. There is noticeable amount of rotational play in the pinion, but nothing up/down/side/side. Doesn't leak, and doesn't seem to effect anything. There is a distinct driveline vibration in it too. Slight whine at some speeds. I attribute a lot of the whine to it not having oil in it when I bought the car. The diff was dry and not making any noise when I got it so I never checked the oil. Then after I'd put around 10k miles on it, it ate an axle bearing. When I opened up the cover, much to my surprise, about a pint of very dark "oil" came out. Ring, pinion, and side gears all looked remarkably good considering the "abuse". Changed both axle bearings, filled it up, and drained and refilled with fresh oil again 1k miles later and what came out was clean with a hint of metal. Filled it back up again and called that good enough. Its been chugging along like that for 50k miles since all that. Still whines slightly most noticeably from 45-50mph, I've had passengers never notice it, but I do. I was considering a junkyard axle swap, one of the local yards had 3 sub-100k 3.08 Town Car axles to choose from for $150-$200, but I chose to just live with it since its working fine.

                        I notice the 3.27 axle in my '98 HPP has the same whine at the same speeds but quieter, which I didn't notice when I test drove it because I've learned to tune it out. When the weather warms up, I'm going to service that diff, as well as throw new u-joints at it since my Town Car u-joints at 90k were past it. Cheap insurance that I'm not unknowingly damaging it IMO.
                        -Steve

                        2006 Audi A6 S-Line FWD ~132k miles, stock.
                        1998 Mercury Grand Marquis LS HPP ~102k miles, slowly acquiring modifications.
                        1997 Lincoln Town Car Cartier ~145k miles, Ported Plenum, Gutted Airbox, Mechanical Fan Delete, Contour E-fan Retrofit, Dual exhaust, Cats ran away, KYB Gas-A-Justs, P71 front sway bar, air ride reinstalled, Blinker Mod, Projector headlight retrofit, Caddy 4-note horn retrofit, Wood rim steering wheel, rustbelt diet plan..
                        1996 Mercury Grand Marquis GS 117,485mi. R.I.P. 7/14/12

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                          #27
                          I've heard that throwing a strong magnet on the cover can help with some of that.
                          1985 LTD Crown Victoria - SOLD
                          1988 Town Car Signature - Current Party Barge

                          Comment


                            #28
                            Originally posted by His Royal Ghostliness View Post
                            ... You're overthinking this, if they got play replace the fuckers, use a quality U-joint - tight U-joints make no clunking noise, ...
                            U-joint related play and clunking aren't issues. I'm getting a bit of funny vibration during the transition from powered to coasting movement, but only at highway speed. I would guess that the one axis that had freer movement (but without slop) is the culprit, and I'll find out soon enough; but in the absence of an emergency, I’m not climbing under my car again until the weather warms up. What’s wrong with wanting to learn how things work in the meantime? I’d love to be able to spend some more time learning more about the Riemann hypothesis, but there doesn’t seem to be much chance of that being productive until my eyes are finally fixed.

                            I turns out that the hybrid U-joints aren't astronomically priced like I thought they would be (as a 'specialty part'), so I'll probably go for whatever decent CVPI aluminum driveshaft comes my way rather than hope for an older one that uses 1330s. I should be able to get price-matching on Spicers (at least the 1330s) at a local place. I would want to be able to use the driveshaft in something else when my current car reaches the end of its life, so I won't cheap out on those.

                            2000 Grand Marquis LS HPP, a hand-me-down in 2008 with 128,000 km; 175,000 km as of July 2014
                            mods: air filter box 'tuba', headlight relay harness, J-mod (around 186,350 km), 70mm throttle body, KYB Gas-A-Just shocks, aluminum driveshaft, ARA3 PCM

                            Comment


                              #29
                              The needle bearings rotate maybe 1/4 turn at most. The less they have to move, the better your shaft alignment is.
                              86 Lincoln Town Car (Galactica).
                              5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley

                              91 Lincoln Mark VII LSC grandpa spec white and cranberry

                              1984 Lincoln Continental TurboDiesel - rolls coal

                              Originally posted by phayzer5
                              I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousers

                              Comment


                                #30
                                I played the video at its slowest speed to clarify the movement of the pair of bearings for the right shaft. I was thinking in terms of whether microscopic people inside the bearings would always see the needles moving back and forth or whether they might actually see the needles moving in only one direction at any point, and it looks like it would be the former.

                                2000 Grand Marquis LS HPP, a hand-me-down in 2008 with 128,000 km; 175,000 km as of July 2014
                                mods: air filter box 'tuba', headlight relay harness, J-mod (around 186,350 km), 70mm throttle body, KYB Gas-A-Just shocks, aluminum driveshaft, ARA3 PCM

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