B (and probably A) Class front brake back plates

[colinallcars]

Got an MoT advisory (probably old terminology?) for a partially insecure and corroded front backplate on a 2013 W246 B Class. I decided to set about replacing it only to discover that it is not sold separately but comes as part of the hub assembly at £358! Contemplating cutting it off so that it can’t do any damage when it lets go completely but would its absence result in an MoT fail?

 

[geoffus]

I recently changed the hub on the wife’s B200 as the bearing magnetic seal had a fault, paid £241 Mercedes’ Edinburg for it, you would be better of leaving it to see if it gets worse or buying a second hand hub from EBay, when I was looking there were a few available as it’s a common problem with the bearing seals needing replacing.
Mercedes B Class (W246) B 200 CDI Steering Knuckle Hub Left Front A2464210720 | eBay

 

[colinallcars]

I recently changed the hub on the wife’s B200 as the bearing magnetic seal had a fault, paid £241 Mercedes’ Edinburg for it, you would be better of leaving it to see if it gets worse or buying a second hand hub from EBay, when I was looking there were a few available as it’s a common problem with the bearing seals needing replacing.
Mercedes B Class (W246) B 200 CDI Steering Knuckle Hub Left Front A2464210720 | eBay

It appears to be a push fit on the hub which has come loose. I’m wondering if a couple of tack welds would hold it though access is tight between the hub and the drive flange. What was involved in swapping it out? Just nuts and bolts or did it need a puller?

 

[geoffus]

It appears to be a push fit on the hub which has come loose. I’m wondering if a couple of tack welds would hold it though access is tight between the hub and the drive flange. What was involved in swapping it out? Just nuts and bolts or did it need a puller?

Its a fairly easy job to remove, no special tools needed.
Looking at it now it appears the plate is spot welded on to the hub, but you will need to remove the bearing to fit the new one.
I did a video when I replaced mine due to an ABS fault, it might help.

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[colinallcars]

Its a fairly easy job to remove, no special tools needed.
Looking at it now it appears the plate is spot welded on to the hub, but you will need to remove the bearing to fit the new one.
I did a video when I replaced mine due to an ABS fault, it might help.

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Thanks for the video, I can make out the spot welds on the new unit. I’ll attempt a repair first and if that fails get a new hub.

 

[colinallcars]

Thanks for the video, I can make out the spot welds on the new unit. I’ll attempt a repair first and if that fails get a new hub.

I bought a used hub from eBay for £40 and, with some decent weather, got round to fitting it but, as with all these things, one problem led to another ……
The replacement part, whilst solid enough, had a fair bit of surface rust so I cleaned it up and gave it a couple of coats of Hammerite. As mentioned above, the actual swap was reasonably straightforward; the hub bolt was tight but yielded to a breaker bar, one of the calliper bracket bolts had seized and had to be butchered out and the ball joint boot had split. A trip to the dealers for a new bolt at £4 and, I hoped, a ball joint boot. Although it had a Mercedes part number (A2463330097) they don’t supply it, their solution being a new lower arm at about £200. I declined this and took to eBay where I found that Febi supply it under part number BZBJB-156, £11.50 including delivery. This part appears to fit a number of models going by the compatibility chart so could save others in a similar situation a bit of cash. I intended to reuse the original wheel sensor but it crumbled as I tried to remove it. Fortunately the breaker had left one attached to the new hub but fitting it involved removing an under tray and the wheel arch liner and working blind to locate and swap the connector, all whilst cursing profusely. Four hours later the job was done and I sincerely hope the MoT inspector appreciates my efforts!