Aeroplane sound and vibration in the rear...

[5150]

Dear sifus,96 model, car just finish total suspension rebuild including subframe, differential and every bushings including rebuilding the rear 2 driveshaft. Got the car yesterday, only managed to test in higher speeds today otw to klia. Everything's perfect except whenever i touch 150km/h, there is this vibration together with the aeroplane noise, both get stronger when i go faster. I'm going to back to the workshop after this but just like the brainstorming here Is the driveshaft the culprit? Eg. Poor balancing job?Tq bros.

 

[mizhan]

could be your wheel bearings.. or your diff tak cukup minyak. better get it checked, altho not many mechanics are willing to test at such speeds.

 

[5150]

Hmm, wheel bearing is a possibility bcoz the other day i only change the front bearings. Axle oil, can't be bro coz no leaking and i changed every 45 - 50k kms.

Tq bro.

 

[jakpo]

Looks like wheel bearing to me.


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[Volvos525i]

Hi Bro...
there is 2 possiblities here may be...
Real wheel bearing or the long shaft not properly balance since have been dismantle right...

 

[greddyevo]

Hi Bro, im not sure if you can select your gear to 4th, drive to 100km/h, hold your handbrake and feel for any vibration. if yes your item no2 is worn.

Try this..Hoist car on jack especially the rear. loosen nut no8, rotate/turn rear tyres back and forth. tighten up nut no8. test again.hope this helps.View attachment 30440

 

[5150]

Hi Bro...
there is 2 possiblities here may be...
Real wheel bearing or the long shaft not properly balance since have been dismantle right...

Hi bro,

My mech as we speak is checking the wheel bearing, bit i got to rush back to office...

Yup, hv to dismantle every under carriage parts but my mech personally check the re-installation b4 i took back the car.

 

[5150]

Hi Bro, im not sure if you can select your gear to 4th, drive to 100km/h, hold your handbrake and feel for any vibration. if yes your item no2 is worn.

Try this..Hoist car on jack especially the rear. loosen nut no8, rotate/turn rear tyres back and forth. tighten up nut no8. test again.hope this helps.View attachment 30440

That's the coupling or giubo as some ppl call it, that rubber coupling is in fine condition as inspected by my mech. But i'll consider your bolt no 8 loosening n tightening. Tq.

 

[Volvos525i]

Hi bro...
please try this simple test...
Jack the rear axle let it stands and on stands...
free the parking brake n set to N...
rotate the rear wheel either to the right or to the left...
If the rear wheel bearing is kaput can feel the rough turning motion on the tyres...

 

[moots]

i am also suspecting the propshaft center support as greddyevo mentioned.you have to preload the support ie move it fwd 3-4 cm.....

 

[greddyevo]

i am also suspecting the propshaft center support as greddyevo mentioned.you have to preload the support ie move it fwd 3-4 cm.....

let me know once you've solved the problem.good luck.

 

[5150]

Dear all,

According to my mech he already did the adjustment to the csb during installation. Now after further driving yesterday
I conclude that the accompanying symptom is from stop, the car feels a bit heavy as if it is turning a "tight"
long shaft or propshaft.

I'm contemplating to change the whole long shaft bcoz i guess it hadn"t been changed since 1996!

Btw the two rear driveshafts had already been rebuilt...

I'll keep posting bros...

 

[moots]

tight propshaft?awww....a propshaft is a dumbass shaft that transmit the propulsion to the rear wheels.
did u change the U joint on the propshaft as well coz that will be the only thing that can cause the shaft to be tight,that also it will wear and loosen as you drive.there must be sumthing else.....

sorry can't offer much help as these kind of issues will be difficult to trace...especially so if it happens @ 150kmh

 

[Volvos525i]

Bro ...
The long shaft is just connecting the motion from eng to the rear axle...
Try check your parking brake free play...

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[5150]

After extensive research in bmw forums, i found out there are many who faced the same problem. And i shared with the ones who rebuild their long shaft. (It's quite confusing with the terms they're using, some call it drive shaft) Anyway those who bought original longshaft whether usedor brand new solved the vibration problem. Those who bought it from "rebuild shops) did not. I understand that only certain parts can be rebuild but the drive line eg. Reciprocating ones like long shafts and drive shafts etc are hard to
rebuild with precision hence vibration problems. We still can use them but have to live with the vibes lah.

But the vibe will also quickly wears out the central support bearing and the giubo (flower like rubber coupling). My mech is ordering a new one and i'll post the outcome, hopefully good this time.

Tq guys!

 

[Volvos525i]

Hi bro.
Well long shaft is the connecting shaft that transfer the movement from eng to gb to axle...so this must be propperly balance if not the vibrate issue arises..as long it is bought 1 pc either new or 2nd not prob...
Hope you could solved your prob...cheers .

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[bmw7833]

How much the brand new one?

 

[Volvos525i]

One of our OM from teluk intan forget his nick bought in kepong for e39 rm900+-

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[Lithium2]

Used long shaft at chop shop is RM800, according to Hakitrade.
Brand New RM4000 according to optimum.

 

[5150]

Yes, my mech just checked brand new price is RM3800. Used ones are stated by our brothers above...