looking how to fix vibrating cardan-shaft

[poisas]

Hello, after i had fixed my gearbox, they have changed in the gearbox 2 bearings, and they changed part no 32. After that, everything seemed fine, but when i got on highway, on 5th gear i started to feel vibration, i can force to vibrate at 110km/h and gently releasing accelerator. and its like some resonance coming in some moment and going away, if If i let go in neutral, no vibration, if i go 150km/h in 4gear, nothing, only vibration in 5th gear, and i can realy start to feel it at 80km/h to hear it like a very low frequency noise. Seems like train going i took car back to the service, and told what is happening, they told me that they never to a propeler shaft away (cardan)
and dont understand how it can be. For me it shows like cardan shaft has lost its balance, here is in other picture i could see a lines where the cardan is hitting aluminium protection in the botoom. they found that the cros was bad( it was stucking when moving it to the middle)

So the question from me is: could it be a hanging bearing? or the cardan has to be rebalanced (only one place in lithuania can do it ) ?

 

[Number_Cruncher]

One thing I've seen is that when (the equivalent of) part 32, the drive flange is changed, the spring inside the oil seal (29) can be dislodged, and can prevent the flange sitting square against the bearing. It's easy enough to check for, as the prop shaft is rotated, look to see if the flange is running true (you may need to rig up a temporary pointer to sight against). The shaft itself can also be checked to see if it's (been) bent using the pointer to sight against.

 

[poisas]

One thing I've seen is that when (the equivalent of) part 32, the drive flange is changed, the spring inside the oil seal (29) can be dislodged, and can prevent the flange sitting square against the bearing. It's easy enough to check for, as the prop shaft is rotated, look to see if the flange is running true (you may need to rig up a temporary pointer to sight against). The shaft itself can also be checked to see if it's (been) bent using the pointer to sight against.

the oil seal was the main problem that damaged bearings and all gearbox.
now the servise says that> first the cross start tu stuck in one place> that start to damage bearings and seal, >bearings became loose>and seal became loose>this cause gearbox oil leaking>then seal start to spin with part 32 and seal was totaly destroyed, and oil was runing off the gearbox, bearings where damaged and split a part in the gearbox> no more driving. they change 2 bearings that were destroyed changed the seal, and part 32. i was cheking several times, no more leaking oil thrue that seal. so there is no movement.

 

[Dieselman]

It can't be the propshaft or output shaft as that would be speed related and not dependent on which gear was selected.

 

[poisas]

It can't be the propshaft or output shaft as that would be speed related and not dependent on which gear was selected.

the more speed, the more vibration i will get when slightly reducing speed or going down hill

but here i realize one thing propelershafts rotations per minute if i drive 100km in 4th gear or 5th gear is the same, so if i can drive easily with 4th gear no vibration, and only in 5th, so this has to be gearbox related. but what that could be ?

 

[Dieselman]

But you don't get vibration when in 4th gear, only 5th. So it can't be the prop-shaft as that is fixed to vehicle speed, not gears or engine speed.

 

[poisas]

so is the question where is that strange vibration coming like DDdddzzzzzghrrrrrr in the moment when slowing down from 110km/h to smth or going downhill ? like the "part from engine to propshaft" becames loose ?


OOhh i think i will take a stethoscope and try to locate where is noise from (ok not me but the passanger i will need to drive )

 

[grober]

Has the propshaft centre bearing or its flexible mount been damaged when the propshaft was dismounted from the gear box drive flange. It must be moving a lot to strike against other objects?
http://www.detali.ru/cat/oem_mb2.as...GM=717.460&CT=F&cat=45P&SID=41&SGR=015&SGN=01

 

[poisas]

Has the propshaft centre bearing or its flexible mount been damaged when the propshaft was dismounted from the gear box drive flange. It must be moving a lot to strike against other objects?
http://www.detali.ru/cat/oem_mb2.as...GM=717.460&CT=F&cat=45P&SID=41&SGR=015&SGN=01

they checked the bearing was OK, but the shaft midle joint it has some little movement like tik tak when you "try to bend it"
and its not an objects its aluminium protection that shaft is hitting,
all the movement is when everything is assembled from the bearing rubbers it
i try to move with my hand i can move it about 1cm up and down but as i see its not prop shaft related

 

[poisas]

today i was in service to the guys that have repaired gearbox, i let them drive with me and listen to the vibration sounds how they are. And they said this might be the 5th gear itself the (how do you call that weel with "teeth"?)
he said it could be dammaged wile it is in the same place where the bearings were replaced, and i was driving with low oil in highway about 55km. So they will change it on tuesday. I see some logic that it could be the 5th gear itself, what do you think could it be so ?