Recently ordered a replacement front wheel bearing/hub for the 05/95 ///M based on the above part#. Upon arrival in the factory-sealed BMW Parts box, noticed that the front wheel bearing/hub does not have the two positioning posts on the hub face that holds the floating rotor on. I double-checked to be sure the part# is for the ///M5 specific part. The part# on the box is correct and there is no part# on the original or new hub, so my question is:
Has BMW discontinued the original front wheel bearing/hub with the positioning posts that are specific to the 345x32mm floating rotor, or did the factory just send the wrong part?
BTW, the wheel hub fits but because there aren't any positioning posts, the rotor is loose when the wheel is off.
Aloha,
David
Last edited by David Chen; 15th January 2007 at 10:39.
That is an interesting situation you have found. So without the pins, what keeps the rotors from sticking to the caliper/pad and letting the wheel spin away?
I am in the throws of planning out a major mod to my M. I am ditching the EDC suspension for an AC Schnitzer setup. I was about to purchase a pair of used 540i (non-M) strut assemblies so that I would have all the right parts to mount up the AC Schnitzer shocks and springs.
Problem is that the wheel hubs which came with standard 540i's are not compatible with the floating rotor M brake rotors. The rotor retaining screw is in the wrong place (see attachment). I was thinking that I could either transplant the hub, or simply drill and tap a new hole for the rotor retaining screw.
But now you have me thinking more about the brakes. Does anyone know if the floating rotor M calipers mount using the same attachment points as calipers for a set of standard 540i brakes?
Hi I don't believe this has changed; I fitted a new wheel bearing end of last year from BMW parts ordered mid 2006 and it had the positioning peices. Can't see why they'd alter it.
Recently ordered a replacement front wheel bearing/hub for the 05/95 ///M based on the above part#. Upon arrival in the factory-sealed BMW Parts box, noticed that the front wheel bearing/hub does not have the two positioning posts on the hub face that holds the floating rotor on. I double-checked to be sure the part# is for the ///M5 specific part. The part# on the box is correct and there is no part# on the original or new hub, so my question is:
Has BMW discontinued the original front wheel bearing/hub with the positioning posts that are specific to the 345x32mm floating rotor, or did the factory just send the wrong part?
BTW, the wheel hub fits but because there aren't any positioning posts, the rotor is loose when the wheel is off.
That is an interesting situation you have found. So without the pins, what keeps the rotors from sticking to the caliper/pad and letting the wheel spin away?
-Burt
Hi!
The wheel bolts.
I would feel a lot more secure with the securing posts in addition to the retaining screw and wheel bolts though
Sakke
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"You can´t afford cheap things if you´re poor"
Could you provide the part# of the correct front wheel hub/bearing that fits the 345x32mm floating rotor? The link in my previous post only shows the standard M5 hub for pre-95 models, even when a 5/95 M5 is the subject vehicle.
David
Quote:
Originally Posted by madm5
Hi I don't believe this has changed; I fitted a new wheel bearing end of last year from BMW parts ordered mid 2006 and it had the positioning peices. Can't see why they'd alter it.
Last edited by David Chen; 20th January 2007 at 05:13.
So if the rotors are attached at the wheel bolts, how are they floating? I thought they were supposed to "float" separately from the hub.
Thanks again for the insights.
The center of the rotor is a separate piece from the disc/contact area for the pads. these are connected with radial metal pins, so that when the disc itself expands from the heat generated under braking, it can "slide" along the pins. The center of the disk is supposed to be firmly fixed between hub and wheel, otherwise it would be rather scary to brake
By the way, even the "small" brakes should have the studs/posts for the disk, I have them in any case.....
Sakke
__________________
"You can´t afford cheap things if you´re poor"
Could you provide the part# of the correct front wheel hub/bearing that fits the 345x32mm floating rotor? The link in my previous post only shows the standard M5 hub for pre-95 models, even when a 5/95 M5 is the subject vehicle.
David
Ops just realised you mean the floating rotor for later models, in that case that is not what I fitted. If you give me the last 7 digits of your VIN i can look up in the BMW parts system I have to see what comes up.
As AlexA pointed out, there is a discrepancy in the realoem.com ETK because it lists the same front wheel hub for all E34 M5s from 1991 onwards, as well as the 850CSi and 750iLS that also came with the floating rotors. If anyone has an older ETK and can locate the proper part#, that would be much appreciated.
Here's a link to a picture of the hub/rotor assembly. Notice the dowel on the hub:
Ops just realised you mean the floating rotor for later models, in that case that is not what I fitted. If you give me the last 7 digits of your VIN i can look up in the BMW parts system I have to see what comes up.
Last edited by David Chen; 26th January 2007 at 04:59.
Change to front wheel bearing (hub)?
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