30-42 mph vibration......

[MO525]

Hello all!
I just picked up a sweet '93 525i automatic for my wife.
It drives FABULOUS except for a pesky vibration that I can feel in the floor/seat in the 30-42 mph range.
In all seriousness, it seems to lessen greatly as the car is driven/"warmed-up".
I know that sounds odd but it's the truth.
I jacked up the car and found the flex disc to have numerous cracks.
Nothing "through" yet but I ordered one (along with new Thrust Arms) from BMA since their price is amazing, compared to the local parts houses/dealers.

Any more insite and/or personal experiences with like vibrations would be GREATLY appreciated.

It COULD be the carrier bearing or the "centering" bearing, from what I hear.
Pulling the exhaust looks to be a chore. :(

Thanks for any help,
Bill

[ryan roopnarine]

and disappoint others, but its likely that it is your flex disc....i had a vibration only at 40 mph in my 92 525i that was due to a bolt missing from the FD, cracks in the FD, and improper nuts being used on the FD bolts......i'm not sure that if you remove the trans crossmember that you will have enough room to remove the FD, but I'd strongly recommend just biting the bullet and removing the exhaust if its a tight fit.....and if you remove the exhaust, strongly recommend you go ahead and do the centering bearing so you can assess the health of the driveshaft, a centering guide replacemet might also be worth your while if you have to pull it, maybe 15 minutes in addition..about 8 hour job or so, the exhaust really isn't that big of a deal to move, at least in the scheme of things, and after you run to the bmw dealership for misc parts a couple of times.....www.bmwe34.net has instructions and a guide under transmissions, and almost everybody here would recommend you buy a bentley manual for $48-70 if you intend to work on your car.

[Brian C.]

and disappoint others, but its likely that it is your flex disc....i had a vibration only at 40 mph in my 92 525i that was due to a bolt missing from the FD, cracks in the FD, and improper nuts being used on the FD bolts......i'm not sure that if you remove the trans crossmember that you will have enough room to remove the FD, but I'd strongly recommend just biting the bullet and removing the exhaust if its a tight fit.....and if you remove the exhaust, strongly recommend you go ahead and do the centering bearing so you can assess the health of the driveshaft, a centering guide replacemet might also be worth your while if you have to pull it, maybe 15 minutes in addition..about 8 hour job or so, the exhaust really isn't that big of a deal to move, at least in the scheme of things, and after you run to the bmw dealership for misc parts a couple of times.....www.bmwe34.net has instructions and a guide under transmissions, and almost everybody here would recommend you buy a bentley manual for $48-70 if you intend to work on your car.

[ryan roopnarine]

and my underlings refer to me as the burger queen!

[Unregistered]

What's a flex disc?




and disappoint others, but its likely that it is your flex disc....i had a vibration only at 40 mph in my 92 525i that was due to a bolt missing from the FD, cracks in the FD, and improper nuts being used on the FD bolts......i'm not sure that if you remove the trans crossmember that you will have enough room to remove the FD, but I'd strongly recommend just biting the bullet and removing the exhaust if its a tight fit.....and if you remove the exhaust, strongly recommend you go ahead and do the centering bearing so you can assess the health of the driveshaft, a centering guide replacemet might also be worth your while if you have to pull it, maybe 15 minutes in addition..about 8 hour job or so, the exhaust really isn't that big of a deal to move, at least in the scheme of things, and after you run to the bmw dealership for misc parts a couple of times.....www.bmwe34.net has instructions and a guide under transmissions, and almost everybody here would recommend you buy a bentley manual for $48-70 if you intend to work on your car.

[Brian C.]

Bruno's site info (http://www.bmwe34.net/e34main/Maintenance/Transmission/CenterBearing.htm)

Go to www.bmwe34.net for all the right info!

Brian C.
:D

[MO525]

Thanks for the response, Ryan.

I KNOW the disc COULD come out BUT......
There's a (for a lack of better terms) "centering pin" that comes out of the tranny output flange which will keep me from being able to fully remove the disc with the driveshaft still in the car, correct?
The driveshaft will not "collapse" on the tranny side of the Carrier Bearing to clear the "pin", the only slip joint is on the Final Drive end. :(

I talked to a shop in town and they'll do it for 3 hours labor (the Flex Disc only).
That shop being "Bimmers R Us". NICE folks and a VERY nice shop.
We'll see.
I'm just scared to death of them "opening up a can of worms" and a 3 hour bill turning into a 6 hour bill with a list of parts as long as my forearm.
I'm sure you can all understand where I'm coming from on that.

I appreciate the response since I need all the moral support I can get.
I'm a daring shade tree mechanic, no problem there. :)

Thanks again!
Bill

[632 Regal]

Give it a whirl...then I'll know how to do it later!

:D

[Bill R.]

pb blaster and letting it soak for at least an hour, then remove the rear section , or in my case I usually pull the whole thing from the downpipe back, it balances fairly well on a floor jack, then you remove the heat shield and unbolt the center support or carrier bearing assy, whichever term you prefer. This is assuming that you've already unbolted the flex coupling.. once you unbolt the center support you can bring the center down enough to pull the front end of the driveshaft off of the centering pin.. But i would look closely at the center support bearing and the rubber surround because its quite likely that its bad too.. If thats the case then its easier to pull the whole driveshaft out instead to give you room to work on it and then you can inspect the ujoints easier...







Thanks for the response, Ryan.

I KNOW the disc COULD come out BUT......
There's a (for a lack of better terms) "centering pin" that comes out of the tranny output flange which will keep me from being able to fully remove the disc with the driveshaft still in the car, correct?
The driveshaft will not "collapse" on the tranny side of the Carrier Bearing to clear the "pin", the only slip joint is on the Final Drive end. :(

I talked to a shop in town and they'll do it for 3 hours labor (the Flex Disc only).
That shop being "Bimmers R Us". NICE folks and a VERY nice shop.
We'll see.
I'm just scared to death of them "opening up a can of worms" and a 3 hour bill turning into a 6 hour bill with a list of parts as long as my forearm.
I'm sure you can all understand where I'm coming from on that.

I appreciate the response since I need all the moral support I can get.
I'm a daring shade tree mechanic, no problem there. :)

Thanks again!
Bill

[MO525]

Give it a whirl...then I'll know how to do it later!

:D

I do hate looking under there and WISHING that darned disc would be removable straight down, no fuss, no muss.
But, thanks to that centering pin, it isn't to be.

I need to get my Thrust Arms installed before tackling the Flex Disc anyhoo.
But I want all my ducks in a row when I do dive into the disc.

[Bill R.]

I do hate looking under there and WISHING that darned disc would be removable straight down, no fuss, no muss.
But, thanks to that centering pin, it isn't to be.

I need to get my Thrust Arms installed before tackling the Flex Disc anyhoo.
But I want all my ducks in a row when I do dive into the disc.

[MO525]

The worst problem is getting the car high enough to work safely/comfortably.
Renting a lift at my friend's shop is VERY tempting.
I may call him tomorrow.
Rather than scooting around on my back using jack stands and ramps. :(

ANY helpful insights and experiences are GREATLY appreciate.
i.e. what works and what doesn't.

Thanks,
Bill

[Muratti]

Guys I have the same vibration between 30 - 35 miles then it goes smooth. How dangerous is to drive the car in this condition? Just plannig a long 700 miles trip...
TIA.

[MO525]

Guys I have the same vibration between 30 - 35 miles then it goes smooth. How dangerous is to drive the car in this condition? Just plannig a long 700 miles trip...
TIA.

Assuming it's the flex disc, it all depends on how deteriorated it is, I guess.
Mine has cracks running from the inside of the ring outwards.
None are "through" but it's just a matter of time.
That is why I'm hell-bent to get it addressed.
If it fails, the driveshaft could do some underside damage to the car, the tranny output flange and possibly the driveshaft as well.

You may want to have it looked at or jack it up with a flashlight and have a look-see yourself.

Better safe than sorry on that sort of trip.

[ryan roopnarine]

that i was only trying to do the stupid FD, but i had every intention of doing the centerbearing as well. its just that, after extricating the fd, and breaking off the three of the six fd bolts (because they were being held on by lug nuts), mein unkle and i realised that despite the amount of pb blaster we put on the differential bolts, they were going to snap off no matter what, and the bmw parts depot was 45 mins away (the dealer was 15 mins, but apparently they don't carry many "parts", and i'd been there twice that day for the fd bolts, and i only had a couple of hours before i needed to return home. that's why i didn't do the centerbearing, as i'd have liked to see what the rear cv joint looked like, and if it needed grease. if you read the bmwe34 thing, you'll see that you don't need to completely take the exhaust off.....if you support it with a jack, you can just lower it and get sufficient clearance to do the center bearing as well. if things fare well for me in the summer, im going to order all six of the differential bolts as well as 4 of the missing muffler supports for my car from bma and do the center bearing and cv joint repack.


Thanks for the response, Ryan.

I KNOW the disc COULD come out BUT......
There's a (for a lack of better terms) "centering pin" that comes out of the tranny output flange which will keep me from being able to fully remove the disc with the driveshaft still in the car, correct?
The driveshaft will not "collapse" on the tranny side of the Carrier Bearing to clear the "pin", the only slip joint is on the Final Drive end. :(

I talked to a shop in town and they'll do it for 3 hours labor (the Flex Disc only).
That shop being "Bimmers R Us". NICE folks and a VERY nice shop.
We'll see.
I'm just scared to death of them "opening up a can of worms" and a 3 hour bill turning into a 6 hour bill with a list of parts as long as my forearm.
I'm sure you can all understand where I'm coming from on that.

I appreciate the response since I need all the moral support I can get.
I'm a daring shade tree mechanic, no problem there. :)

Thanks again!
Bill