for those with urethane diff bushings
04-18-2017, 03:02 PM
#1
Registered User
Thread Starter
for those with urethane diff bushings
I had the diff bushings done last year and ever since ive been dealing with driveline vibrations. Have those of you who have the urethane diff bushings noticed increased vibrations? Sometimes i get a lashout heavy vibration when slowing down in 3rd gear.
04-18-2017, 03:14 PM
#2
have you tried installing the front diff bushings flipped (i.e. thicker ones on top or bottom)?
also your driveshaft may have been reinstalled out of phase (lol, i don;t know if this is the right way to refer to it).....if I recall correctly there is procedure in the FSM for getting rid of vibrations after disconnecting the driveshaft. basically you disconnect it at the differential rotate it one bolt, put it together, test drive and repeat the process until its at its quietest/the vibrations are gone. (this is a PIA and why you're supposed to mark the driveshaft at the pinion when its disassembled...there may even be a factory marking)
other than the two possibilities above the new bushings may have caused the centre support bearing to fail as its probably as old and worn/made of soft rubber as the diff bushing you had to replace so maybe inspect that and change it if you need to
also your driveshaft may have been reinstalled out of phase (lol, i don;t know if this is the right way to refer to it).....if I recall correctly there is procedure in the FSM for getting rid of vibrations after disconnecting the driveshaft. basically you disconnect it at the differential rotate it one bolt, put it together, test drive and repeat the process until its at its quietest/the vibrations are gone. (this is a PIA and why you're supposed to mark the driveshaft at the pinion when its disassembled...there may even be a factory marking)
other than the two possibilities above the new bushings may have caused the centre support bearing to fail as its probably as old and worn/made of soft rubber as the diff bushing you had to replace so maybe inspect that and change it if you need to
04-18-2017, 03:19 PM
#3
Hashim, you're talking about indexing the driveshaft. I don't know if Nissan balanced the individual components or the entire rotating assembly, but your method is a good one to try. For those who intend to remove the drive shaft for some reason, mark one of the bolts and its flange so you can put it back together as it came apart to minimize imbalances.
I need to look at my diff to see if the bushing has puke its fluid.
I need to look at my diff to see if the bushing has puke its fluid.
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Baadnewsburr (04-18-2017)
04-18-2017, 03:30 PM
#5
Registered User
Thread Starter
have you tried installing the front diff bushings flipped (i.e. thicker ones on top or bottom)?
also your driveshaft may have been reinstalled out of phase (lol, i don;t know if this is the right way to refer to it).....if I recall correctly there is procedure in the FSM for getting rid of vibrations after disconnecting the driveshaft. basically you disconnect it at the differential rotate it one bolt, put it together, test drive and repeat the process until its at its quietest/the vibrations are gone. (this is a PIA and why you're supposed to mark the driveshaft at the pinion when its disassembled...there may even be a factory marking)
other than the two possibilities above the new bushings may have caused the centre support bearing to fail as its probably as old and worn/made of soft rubber as the diff bushing you had to replace so maybe inspect that and change it if you need to
also your driveshaft may have been reinstalled out of phase (lol, i don;t know if this is the right way to refer to it).....if I recall correctly there is procedure in the FSM for getting rid of vibrations after disconnecting the driveshaft. basically you disconnect it at the differential rotate it one bolt, put it together, test drive and repeat the process until its at its quietest/the vibrations are gone. (this is a PIA and why you're supposed to mark the driveshaft at the pinion when its disassembled...there may even be a factory marking)
other than the two possibilities above the new bushings may have caused the centre support bearing to fail as its probably as old and worn/made of soft rubber as the diff bushing you had to replace so maybe inspect that and change it if you need to
Im considering yanking the driveshaft and having a shop rebalance the unit as a whole and have the ujoints replaced as well and hope that solves the problem. When i did the center bearing it never occurred to me the shafts could have been balanced assembled and needed to be lined up properly. I just figured each one was self balanced and self contained as its own unit and that it wouldnt matter where each shaft was indexed since they were round.
04-18-2017, 03:32 PM
#6
Registered User
Thread Starter
Mines RWD. Ill have to look and see if theres a factory mark at the diff. That would be nice so i could line it up and then try reindexing at the shaft split center bearing.
04-18-2017, 03:39 PM
#7
The driveshaft was actually out of clock after i replaced the carrier center bushing as my first attempt to get rid of the vibrations. This made it worse until i one bolt at a time clocked it until it got better. I clocked it by the bolts at the split in driveshaft though not at the diff. For the most part theres very little vibration, but i do have this random lashout issue still. Maybe i will try clocking the diff side and see if that helps. Even the new carrier bearing is so soft that its hard to tell if its still good or was damaged by the vibrations.
Im considering yanking the driveshaft and having a shop rebalance the unit as a whole and have the ujoints replaced as well and hope that solves the problem. When i did the center bearing it never occurred to me the shafts could have been balanced assembled and needed to be lined up properly. I just figured each one was self balanced and self contained as its own unit and that it wouldnt matter where each shaft was indexed since they were round.
Im considering yanking the driveshaft and having a shop rebalance the unit as a whole and have the ujoints replaced as well and hope that solves the problem. When i did the center bearing it never occurred to me the shafts could have been balanced assembled and needed to be lined up properly. I just figured each one was self balanced and self contained as its own unit and that it wouldnt matter where each shaft was indexed since they were round.
Oh and don't forget to try swapping (top/bottom) the bushings at the front of the diff as I've read others have tried that on here and it appeared to have helped...
be sure to update with your results as I'm very curious
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04-19-2017, 10:30 AM
#8
Registered User
Thread Starter
The carrier bearing i got should be oem as it cost 135. It was a difficult part to find and i ended up having to get it from an online infiniti dealer. I didnt actually do the diff bushing install, i had a local shop do it because the rear one needs some serious work to remove. I'd like to flip the front bushings over, but im not sure how hard they will be to get out or if i actually need to drop the diff to do it. Maybe ill just get under there this weekend since its such easy access and see how far i get before its done or i need to stop and reassemble.
04-19-2017, 10:56 AM
#9
Two Piece drive shafts should always be balanced together. As far as I know all OEMs do it this way. Balancing as individual units doesn't generally produce acceptable results (it can, but thats more luck than anything).
Incorrect indexing (or clocking or phasing) is a very common mistake from garages.
Aftermarket carrier bearings are mostly trash. A few good manufacturers out there, but they mostly do domestic fitments. For Most asian cars OEM is the safest bet.
Incorrect indexing (or clocking or phasing) is a very common mistake from garages.
Aftermarket carrier bearings are mostly trash. A few good manufacturers out there, but they mostly do domestic fitments. For Most asian cars OEM is the safest bet.
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Baadnewsburr (04-20-2017)
04-19-2017, 01:02 PM
#10
The carrier bearing i got should be oem as it cost 135. It was a difficult part to find and i ended up having to get it from an online infiniti dealer. I didnt actually do the diff bushing install, i had a local shop do it because the rear one needs some serious work to remove. I'd like to flip the front bushings over, but im not sure how hard they will be to get out or if i actually need to drop the diff to do it. Maybe ill just get under there this weekend since its such easy access and see how far i get before its done or i need to stop and reassemble.
If it helps, to flip the front bushings it should not be to much trouble, you just need to:
1.Get a jack under the diff to support its weight and undo the two bolts holding the front of the diff to the subframe.
2. Then lower the jack a bit so it tilts down a couple of inches but still supports its weight.
3. then use a flat screwdriver to pry the poly bushing halves out and then pop them back in by hand (in swapped potions) they should come out pretty easy.
4.Then raise the jack again and reassemble.
This is about 15-20 mins of work once you have the car up on jack stands.
You may need to undo the the rear sway bar bushings to let it lower a bit to get it out out of the way of your tools (requires undoing 4 14mm bolts) and remove the four little 10mm bolts to get the rear driveshaft shield out of the way which may add another 5 to ten minutes
As long as you never lower the jack so that its always supporting the weight of the diff it shouldn't put any undue stress on the driveshaft
04-19-2017, 09:09 PM
#12
have you tried installing the front diff bushings flipped (i.e. thicker ones on top or bottom)?
also your driveshaft may have been reinstalled out of phase (lol, i don;t know if this is the right way to refer to it).....if I recall correctly there is procedure in the FSM for getting rid of vibrations after disconnecting the driveshaft. basically you disconnect it at the differential rotate it one bolt, put it together, test drive and repeat the process until its at its quietest/the vibrations are gone. (this is a PIA and why you're supposed to mark the driveshaft at the pinion when its disassembled...there may even be a factory marking)
other than the two possibilities above the new bushings may have caused the centre support bearing to fail as its probably as old and worn/made of soft rubber as the diff bushing you had to replace so maybe inspect that and change it if you need to
also your driveshaft may have been reinstalled out of phase (lol, i don;t know if this is the right way to refer to it).....if I recall correctly there is procedure in the FSM for getting rid of vibrations after disconnecting the driveshaft. basically you disconnect it at the differential rotate it one bolt, put it together, test drive and repeat the process until its at its quietest/the vibrations are gone. (this is a PIA and why you're supposed to mark the driveshaft at the pinion when its disassembled...there may even be a factory marking)
other than the two possibilities above the new bushings may have caused the centre support bearing to fail as its probably as old and worn/made of soft rubber as the diff bushing you had to replace so maybe inspect that and change it if you need to
04-20-2017, 08:47 AM
#13
Registered User
Thread Starter
If you do decide to reindex the shaft dont remove all the bolts at once. Remove all but one then with one hand pull it out enough to rotate the shaft with the other hand then slip the bolt back in. This way you wont lose your index starting position. Also you may want to mark the one bolt in case its more than a day until you try another rotation.
A word of caution about doing this in your garage. You do need to jack the car up and then put the car in nuetral as well as let off the hand brake or the shaft wont rotate. This is a very precarious situation for a DIY mechanic to be in so make sure youre using jack stands and i would suggest also using chocks on the front wheels.
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04-20-2017, 08:50 AM
#14
Registered User
Thread Starter
Yeah thats definitely an OEM piece price...I'm sure its not the problem then.
If it helps, to flip the front bushings it should not be to much trouble, you just need to:
1.Get a jack under the diff to support its weight and undo the two bolts holding the front of the diff to the subframe.
2. Then lower the jack a bit so it tilts down a couple of inches but still supports its weight.
3. then use a flat screwdriver to pry the poly bushing halves out and then pop them back in by hand (in swapped potions) they should come out pretty easy.
4.Then raise the jack again and reassemble.
This is about 15-20 mins of work once you have the car up on jack stands.
You may need to undo the the rear sway bar bushings to let it lower a bit to get it out out of the way of your tools (requires undoing 4 14mm bolts) and remove the four little 10mm bolts to get the rear driveshaft shield out of the way which may add another 5 to ten minutes
As long as you never lower the jack so that its always supporting the weight of the diff it shouldn't put any undue stress on the driveshaft
If it helps, to flip the front bushings it should not be to much trouble, you just need to:
1.Get a jack under the diff to support its weight and undo the two bolts holding the front of the diff to the subframe.
2. Then lower the jack a bit so it tilts down a couple of inches but still supports its weight.
3. then use a flat screwdriver to pry the poly bushing halves out and then pop them back in by hand (in swapped potions) they should come out pretty easy.
4.Then raise the jack again and reassemble.
This is about 15-20 mins of work once you have the car up on jack stands.
You may need to undo the the rear sway bar bushings to let it lower a bit to get it out out of the way of your tools (requires undoing 4 14mm bolts) and remove the four little 10mm bolts to get the rear driveshaft shield out of the way which may add another 5 to ten minutes
As long as you never lower the jack so that its always supporting the weight of the diff it shouldn't put any undue stress on the driveshaft
04-20-2017, 10:28 AM
#15
If you didnt have the vibrations since the day the bushings were installed then its probably not the driveshaft indexing thats the problem. How old is your carrier bearing? I would suspect it if its been awhile after the bushing replacement when it suddenly started vibrating. I read how a bunch of people changed to the whiteline bushings and subsequently had to replace the carrier bearing.
If you do decide to reindex the shaft dont remove all the bolts at once. Remove all but one then with one hand pull it out enough to rotate the shaft with the other hand then slip the bolt back in. This way you wont lose your index starting position. Also you may want to mark the one bolt in case its more than a day until you try another rotation.
A word of caution about doing this in your garage. You do need to jack the car up and then put the car in nuetral as well as let off the hand brake or the shaft wont rotate. This is a very precarious situation for a DIY mechanic to be in so make sure youre using jack stands and i would suggest also using chocks on the front wheels.
If you do decide to reindex the shaft dont remove all the bolts at once. Remove all but one then with one hand pull it out enough to rotate the shaft with the other hand then slip the bolt back in. This way you wont lose your index starting position. Also you may want to mark the one bolt in case its more than a day until you try another rotation.
A word of caution about doing this in your garage. You do need to jack the car up and then put the car in nuetral as well as let off the hand brake or the shaft wont rotate. This is a very precarious situation for a DIY mechanic to be in so make sure youre using jack stands and i would suggest also using chocks on the front wheels.
This is spot on. And the explanation is excellent. If the problem developed later its probably something different.
The only thing I would add though is that you should be able to leave it in park when you disconnect the driveshaft from the pinion flange, but instead of rotating the driveshaft you rotate one of the wheels so the pinion moves. You will need to disengage the parking brake for this though and it requires mores muscle and it may be harder to line up (easier with a 2nd set of hands). If you want to rotate the drive shaft you should only have to put it in neutral (Parking brake wont matter if the rear wheels are up in the air.)....as was mentioned you need to be very careful and use chocks on the front if you leave the front wheels on the ground or better yet have a professional do it for the sake of safety
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xxg00w0 (04-20-2017)