E36 drive vibration
Discussion
I've just fitted an LSD from a 3.0 M3 to my '96 328i, and I now have a vibration under load 
It increases with engine speed, not road speed, so that leads me to think its prop shaft realted, as I had to fit the M3 prop aswell. But I've been underneath, and checked all the bolts are tight etc, and everything seems fine.
Does anyone know what might be causing this? Its alot more noticable under load and at higher revs. I think with careful driving it would be possible to not notice at all.
It increases with engine speed, not road speed, so that leads me to think its prop shaft realted, as I had to fit the M3 prop aswell. But I've been underneath, and checked all the bolts are tight etc, and everything seems fine.
Does anyone know what might be causing this? Its alot more noticable under load and at higher revs. I think with careful driving it would be possible to not notice at all.
If it increase with engine speed, and not road speed, then that would almost discount the prop, which turns relative to road speed only.
I think what it's changing with is torque, the more torque (from increasing revs) gives you more vibration.
I'd say either the prop was split and reconnected out of balance, or more likely, the centre bearing is worn, and it's spinning out of true a little.
I think what it's changing with is torque, the more torque (from increasing revs) gives you more vibration.
I'd say either the prop was split and reconnected out of balance, or more likely, the centre bearing is worn, and it's spinning out of true a little.
TheEnd said:
If it increase with engine speed, and not road speed, then that would almost discount the prop, which turns relative to road speed only.
Ahh yes, dont know how I missed that??TheEnd said:
I think what it's changing with is torque, the more torque (from increasing revs) gives you more vibration.
I'd say either the prop was split and reconnected out of balance, or more likely, the centre bearing is worn, and it's spinning out of true a little.
Makes sense. do you know easy are the bearings to change? Or how do I go about finding out?I'd say either the prop was split and reconnected out of balance, or more likely, the centre bearing is worn, and it's spinning out of true a little.
Cheers
Ed
The bearing is pretty easy.
It's the metal circle that help the middle of the prop.
You might get away leaving the exhaust on, but it's easier with it off, or just loosened.
You'll have a bolt in the middle of the prop to split it into each half, and slide the bearing with it's carrier off. slip a new one on and that's it.
One thing that is usually recommended is marking the prop so it goes back together in the same orientation as they are balanced as a whole. It may be that yours was balanced, but is now 180 degrees out or something making it very unbalanced, but that's pretty rare to feel one that is way out.
An unbalanced prop would shake at all speeds, but as you get it most when under power, i'd imagine it's the bearing.
http://www.realoem.com/bmw/showparts.do?model=BF92...
It comes as 6+7 together.
Also check the bolts on the prop coupling too, number 2, bolts no.5.
I reused my old ones which then worked loose, and one bolt came out and decapitated itself on the gearbox with a very loud bang on the motorway and a chunk of alloy gouged out. I was lucky i didn't shatter the lot!
It's the metal circle that help the middle of the prop.
You might get away leaving the exhaust on, but it's easier with it off, or just loosened.
You'll have a bolt in the middle of the prop to split it into each half, and slide the bearing with it's carrier off. slip a new one on and that's it.
One thing that is usually recommended is marking the prop so it goes back together in the same orientation as they are balanced as a whole. It may be that yours was balanced, but is now 180 degrees out or something making it very unbalanced, but that's pretty rare to feel one that is way out.
An unbalanced prop would shake at all speeds, but as you get it most when under power, i'd imagine it's the bearing.
http://www.realoem.com/bmw/showparts.do?model=BF92...
It comes as 6+7 together.
Also check the bolts on the prop coupling too, number 2, bolts no.5.
I reused my old ones which then worked loose, and one bolt came out and decapitated itself on the gearbox with a very loud bang on the motorway and a chunk of alloy gouged out. I was lucky i didn't shatter the lot!
TheEnd said:
The bearing is pretty easy.
It's the metal circle that help the middle of the prop.
You might get away leaving the exhaust on, but it's easier with it off, or just loosened.
You'll have a bolt in the middle of the prop to split it into each half, and slide the bearing with it's carrier off. slip a new one on and that's it.
One thing that is usually recommended is marking the prop so it goes back together in the same orientation as they are balanced as a whole. It may be that yours was balanced, but is now 180 degrees out or something making it very unbalanced, but that's pretty rare to feel one that is way out.
An unbalanced prop would shake at all speeds, but as you get it most when under power, i'd imagine it's the bearing.
http://www.realoem.com/bmw/showparts.do?model=BF92...
It comes as 6+7 together.
Also check the bolts on the prop coupling too, number 2, bolts no.5.
I reused my old ones which then worked loose, and one bolt came out and decapitated itself on the gearbox with a very loud bang on the motorway and a chunk of alloy gouged out. I was lucky i didn't shatter the lot!
Thanks, that realoem is brilliant It's the metal circle that help the middle of the prop.
You might get away leaving the exhaust on, but it's easier with it off, or just loosened.
You'll have a bolt in the middle of the prop to split it into each half, and slide the bearing with it's carrier off. slip a new one on and that's it.
One thing that is usually recommended is marking the prop so it goes back together in the same orientation as they are balanced as a whole. It may be that yours was balanced, but is now 180 degrees out or something making it very unbalanced, but that's pretty rare to feel one that is way out.
An unbalanced prop would shake at all speeds, but as you get it most when under power, i'd imagine it's the bearing.
http://www.realoem.com/bmw/showparts.do?model=BF92...
It comes as 6+7 together.
Also check the bolts on the prop coupling too, number 2, bolts no.5.
I reused my old ones which then worked loose, and one bolt came out and decapitated itself on the gearbox with a very loud bang on the motorway and a chunk of alloy gouged out. I was lucky i didn't shatter the lot!
Just ordered anew bearing and mount, £50odd quid plus VAT.I'm also going to try moving the CV joint at the front of the diff, as it wasn't marked up which way it was connected before it was removed from the M3.
We also had to cut of 2 of the 328 halfshaft bolts, and used 2 from the M3, which were longer, so we packed them out with washers. I know its only a few grammes, but would this add to the problem?
Gassing Station | BMW General | Top of Page | What's New | My Stuff