Tin Can / Bottom Scraping Noise

[peter_s]

My tin can noise went away after I did the exhaust valve mod.

Before I heard it when letting off the gas or braking, sometimes accelerating. I haven't heard it since I installed the valve flap module.

[Bluex]

Originally Posted by peter_s

My tin can noise went away after I did the exhaust valve mod.

Before I heard it when letting off the gas or braking, sometimes accelerating. I haven't heard it since I installed the valve flap module.

This is something else entirely. You're talking about the exhaust rattle sound on cold start when the flaps are closed. You are right, the valve mod does fix that

However, this thread is about brake shields that do not have enough clearance to the rotor and thus pebbles getting caught between the two. When this happens you usually hear a LOUD "screetching" sound followed by the sound of debris in a "tin can" while driving. A quick and dirty fix is to simply push the shields back from the rotor a bit allowing the debris to find it's way out.

If you haven't experienced this yet, count yourself lucky....makes you feel like you're driving a hoopty at times. And trust me, you'd know it!

However, BMW has released new rear brake shields that supposedly correct the issue.

[peter_s]

Originally Posted by Bluex

This is something else entirely. You're talking about the exhaust rattle sound on cold start when the flaps are closed. You are right, the valve mod does fix that

However, this thread is about brake shields that do not have enough clearance to the rotor and thus pebbles getting caught between the two. When this happens you usually hear a LOUD "screetching" sound followed by the sound of debris in a "tin can" while driving. A quick and dirty fix is to simply push the shields back from the rotor a bit allowing the debris to find it's way out.

If you haven't experienced this yet, count yourself lucky....makes you feel like you're driving a hoopty at times. And trust me, you'd know it!

However, BMW has released new rear brake shields that supposedly correct the issue.

I had problems for a long time locating my problem, so I thought it was the brake shield you fellas described here. Then it went away after my mod. I'll wait for the screetch then with pleasure

[Stryatch]

Originally Posted by darge82

The wheel bearings will get replaced as well. The SIB references the repair instructions. When you look up the repair instructions the wheel hub must be removed. When the hub is removed it destroys the bearing because it takes the inner race with it when you pull it out of the bearing. There is no way around it. All cars getting shields will also be getting wheel bearings.

Darge82,
this is from my tech:

I have looked over the information you have sent and no, the bearings do not need to be replaced. I have looked over the repair instructions and the tech has followed them correctly. If either the bearing or flange needed to be replaced, then yes, the bearing would be damaged due to the race separating from the bearing. In this repair, the axle was taken out of the flange and the bearing/flange assembly was left together. I have attached a picture showing the complete unit. The four bolts that hold the bearing to the knuckle were replaced according to repair instructions as well as the axle nuts.

I don't want my wheels falling off, lol ...are we all good?

thanks,
stryatch

[GregW / Oregon]

Originally Posted by Stryatch

Darge82,
this is from my tech:

I have looked over the information you have sent and no, the bearings do not need to be replaced. I have looked over the repair instructions and the tech has followed them correctly. If either the bearing or flange needed to be replaced, then yes, the bearing would be damaged due to the race separating from the bearing. In this repair, the axle was taken out of the flange and the bearing/flange assembly was left together. I have attached a picture showing the complete unit. The four bolts that hold the bearing to the knuckle were replaced according to repair instructions as well as the axle nuts.

I don't want my wheels falling off, lol ...are we all good?

thanks,
stryatch

Pic?

[Stryatch]

Thanks for the post darge82!

[GregW / Oregon]

Got mine done today (in addition to replacing my squealing Dinan exhaust). Bearings replaced. Both jobs completed in one day.

[WVUDrJay]

Anyone going to get their heat shields replaced, make sure they order the two bolts or bearings or whatever they are that are not reusable once the shields are replaced. They did not do this and it cost me an extra day without my car.

[Arcades]

Originally Posted by WVUDrJay

Anyone going to get their heat shields replaced, make sure they order the two bolts or bearings or whatever they are that are not reusable once the shields are replaced. They did not do this and it cost me an extra day without my car.

This is true. I was without my gal for 3-4 days because they didn't have all of the parts but I had my loaner with me so it was fine.

I'm only hyper picky if they did a poor job which didn't seem so. Did have to break in heat shield again, like after you washed your car.

[WVUDrJay]

Originally Posted by Arcades

This is true. I was without my gal for 3-4 days because they didn't have all of the parts but I had my loaner with me so it was fine.

I'm only hyper picky if they did a poor job which didn't seem so. Did have to break in heat shield again, like after you washed your car.

Hopefully picking up tomorrow. It's been almost a week. I'm gonna break them in alright!!!!

By driving it like I stole it

[BuLoOoSki]

darge82 I recently had the dealership change out my rear backing plates according to SI B34 06 15. The work order sheet does not mention anything about bearings being changed, it just mentions that backing plates were replaced according to the SIB. So should I assume that it also involved changing the bearings as part of the process or could they have not done that?

P.S. My car did stay at the dealership for two days because they didn't have the new backing plate in stock, not sure if anything else was ordered as well though.

[specracer]

+1 mine rears were done last week. Waited 3-4 weeks for the parts to arrive, but was completed in a few hours the same day.

[curehead]

Both my rear shields were replaced over one month ago but the scraping noise re-appeared and I didn't manage to get rid of it by pushing the shields back by hand so i had to continue drive the car until the stone finally came out or was worn down... Anyway, just to say the new shields are no guarantee that it does not re-appear

[BuLoOoSki]

Originally Posted by darge82

Does your work order show the parts that were used? PM me the last 7 digits of your VIN I can check.

On the work order it's just showing part number: 34-21-2-284-745

Sent you a PM with my VIN, thanks for taking the time to check.

[DocWeatherington]

Originally Posted by curehead

Both my rear shields were replaced over one month ago but the scraping noise re-appeared and I didn't manage to get rid of it by pushing the shields back by hand so i had to continue drive the car until the stone finally came out or was worn down... Anyway, just to say the new shields are no guarantee that it does not re-appear

Plus 1... The new shields aren't a guarantee. I got this "fixed" last Thursday..

However I have noticed it's not as loud and will self correct.

I have now taken it as being a personality of the car. Dan.. your not driving with enough aggression...

[F82speed]

I got the mother screech of all screeches Friday night, holy crap sounds like brakes/bearings but I know it's a rock in the shield. Bent the shields, pulled the wheel and bent the shields some more, reassembled and hauled ass in reverse then sprayed with high pressure water and did some more hauling ass backwards, all to no avail. All of that did nothing but slightly change the tone of the sound at times.

Good to see there's a service bulletin so I'll take it in tomorrow morn. Thanks for the info, guess I should consider myself lucky since this is the first it's happened other than a few times for only 5-10 seconds in 7k miles.

[Bluex]

My service for this replacement is being completed right now, and I specifically asked about whether or not the bearings need to be replaced. My SA spoke with the tech doing the work and his response was:

"Replacement of the bearings is only when you have press in bearings,yours are bolted on and therefore this repair is not needed."

Will post the full service invoice when I pick it up later today.

[Bluex]

New brake shields installed. Attached is the service invoice with part number.

Btw, agreed, it will still occur....and probably need breaking in.

With my old "custom bent" shields, I hadn't heard the shrieking in 2 months, but with these new "improved" shields, I heard the sound while driving the car home from the dealer. Mind you, it wasn't a long a pronounced sound, just a little "yelp". I'll keep an eye (or an ear) on it.....

[sos]

Couldn't get a stone out of mine.....took it in to the dealer yesterday, new shields and hubs being fitted. Also a full KDS alignment being done to check geometry.

Lots of work for a tiny little stone!!

[F82speed]

Originally Posted by darge82

Does your work order show the parts that were used? PM me the last 7 digits of your VIN I can check.

I called to schedule on Monday morning and asked the SA to verify that they had all required parts per the TSB, including the bearings and one time use bolts. They did not, but had them delivered the next day (Tues.) and scheduled me for Wed. morning. That rock actually came out Tuesday night coincidentally, but figured I'd take it in anyway since they had the parts and had me scheduled. So I dropped off first thing Wed. morn and of course they then called Wed. afternoon to say they needed to keep it overnight, but NOT because of parts, they supposedly had them all, but because it was taking much longer than they had originally anticipated, without being able to tell me why except that the tech was "struggling with the one side." It wasn't until 1pm yesterday afternoon that the SA called to say it was done, at which point upon my questioning, he said they didn't replace the bearings because they didn't pull the hub, but instead the foreman had "figured out a way" to replace the plates without pulling the hub thereby necessitating the bearing replacement. I said I assume then that he pulled the axle to which he replied "no, I know he didn't drop the axle." I said well there's no other way you'd be able to remove and replace the plates and which point he got wishy washy and tacitly agreed. He committed to getting me more detail on the job and I'm waiting on his call now, but here's the invoice referencing the same repair instruction that calls out the hub removal. Parts listed are the Plates and bolts and nuts, but no bearings. I assume they must have pulled the axle... thoughts?

[secretariat]

I got the bulletin done on my car also. From what I understand there are two ways to get this done, 1-to replace the bearings when they remove the plate the other way 2- is the long way around where it's more work for the mechanic but the bearings do not have to be replaced. Now with this in mind I would certainly question them because they seem to be hazy with the answers they are giving you. Also keep in mind that the pebbles still get stuck in there, but for a shorter period of time. All the pebbles that have been stuck in there since I got the service done have come out immediately after making a little noise. I do not have to put my car in reverse any more and floor it to remove pebbles.

[zillymc]

My SA told them that on the 2016s they've changed the brake shielding so there's more room for things to fall through/not get stuck. Not sure if there's any validity to this but at my 1200 mile service I explained I had a clicking noise on wheel rotation and that a twig/rock might be stuck in brake shielding, that's when he told me about the 2016s that BMW changed them to have a bit more space.

That being said, they did find the source of the clicking, they found a rock (about size of a dime), embedded into my tire! It was shaved down almost flat on one half so that's what it was.