loud clunking from rear on fast right turns

[Pablo M]

Couple videos:

one of the axles turning and the condition of some bushings. 
Other of the exhaust as I shake it. 
 

photos are of where exhaust hits underside of body near csb,

second is forward exhaust mount showing (hopefully) how the metal bracket isn’t even being supported by the rubber mount. Both mounts, forward and behind muffler are new. 

[larry_in_socal]

Perhaps there is too much slack in the hanger, isn't there supposed to be some sort of plastic hanger support? and does this take some of the slack out of the mount. I would assume that if BMW had both a rubber and plastic support, they worked in conjunction to tighten up the mount, you know German engineering stuff.

 

 

Edited March 2, 2023 by larry_in_socal

[larry_in_socal]

Also, I think that the plastic mount support prevents the rear hanger from cutting into the rubber hanger as the rubber and metal colliding together is not a good thing, making the hanger basically become a dull knife cutting over time.

[Pablo M]

1 hour ago, larry_in_socal said:

Perhaps there is too much slack in the hanger, isn't there supposed to be some sort of plastic hanger support? and does this take some of the slack out of the mount. I would assume that if BMW had both a rubber and plastic support, they worked in conjunction to tighten up the mount, you know German engineering stuff.

Also, I think that the plastic mount support prevents the rear hanger from cutting into the rubber hanger as the rubber and metal colliding together is not a good thing, making the hanger basically become a dull knife cutting over time.

You're right. I hadnt noticed I was missing a piece. There werent any when I got the car so I replaced the hangers only. I remember thinking exactly that-they seemed like eminent failure given the sharp edge on the hanger. Surprised I didnt see that in the RealOEM diagrams before. $10 each! Dang. Add it to the list.

Thanks!

 

When I discovered the rear noise I was taking the car for the first longer shake down run after just getting the engine to purr. 40+ miles on PCH and just a hint of canyons. On the way back started to run badly again, like it was missing. Could have developed another vacuum leak or possibly fouled the plugs due to blow by. I dont know why I fear the latter or why I even thought of it lol. So no testing for a bit till I get engine sorted again.

[Einspritz]

If you have a 3D printer there is a file for that.

 

And is it just me or does the differential not have any fluid in it? Cause it sounds that way.

[Pablo M]

12 minutes ago, Einspritz said:

If you have a 3D printer there is a file for that.

 

And is it just me or does the differential not have any fluid in it? Cause it sounds that way.

I dont but know people so could have it printed.

 

I drained and filled the diff so I know its got fluid. No signs of any loss, but if you think it really sounds like it is empty I can check it easily.

[beammmer]

5 hours ago, jgerock said:

That was Vintage 2009 correct?  Matthew Cervi and I rode in the back seat for a sound check of the noises. 🤷🏻‍♂️

Yes it was Jim, good memory and the best location for the Vintage. 
 

Don

[Einspritz]

21 hours ago, Pablo M said:

I dont but know people so could have it printed.

 

I drained and filled the diff so I know its got fluid. No signs of any loss, but if you think it really sounds like it is empty I can check it easily.

Thingverse for the part. Search BMW 2002 and scroll.......

 

The diff just sounded a bit loud.......

[Schnellvintage]

You may want to pull the diff cover off and double check the play (damaged teeth) with the spider gears.

I have seen them missing teeth and be still ok straight but in an aggressive turn under power make a clunking or clicking sound.  It'll cost you a gasket and you can still capture, reuse the clean oil, if so desired.

 

fwiw,

Matt

Edited March 3, 2023 by Schnellvintage
typo

[Pablo M]

3 minutes ago, Einspritz said:

Thingverse for the part. Search BMW 2002 and scroll.......

 

The diff just sounded a bit loud.......

Yep, a friend already printed out a couple for me. I’ll pick them up Saturday. 
 

I’ll check again but I’m sure I put in the right amount of oil, just to where it was dripping out.  I can pop the drain plug open again to check the level. If it has oil and is still loud what could that mean? I used Redline 75W90 GL-5 synthetic oil. 

[Pablo M]

3 minutes ago, Schnellvintage said:

You may want to pull the diff cover off and double check the play (damaged teeth) with the spider gears.

I have seen them missing teeth and be still ok straight but in an aggressive turn under power make a clunking or clicking sound.  It'll cost you a gasket and you can still capture, reuse the clean oil, if so desired.

 

fwiw,

Matt

When I refreshed the oil I also pulled the diff cover and checked inside. Main reason was there was evidence of long term oil seepage on the outside and I wanted to redo the gasket and oil. When I had the cover off I looked in and didnt see any tell tale signs of damaged teeth, nothing on the bottom of the case and nothing that I could see in teh oil that came out. I didnt do a full inspection though so could have missed damaged teeth.

Someone once mentioned, related to something else, that it could be diff related: on deceleration I can hear a metal scraping noise. Could be related to the noisy diff when I turn it. I suppose I could pull the cover again and spin the gears to see how they are. So many things to do...lol.

Thanks!

[Schnellvintage]

Here is an example of a bad spider gear.  One tooth can cause a problem.  This one didn't make noise, at the time, but it would have, if I left it in there after a rebuild.   

I found the diff animation on the interwebs.  It what goes on around a curve. (you probably knew that already)

Matt

[Pablo M]

5 minutes ago, Schnellvintage said:

Here is an example of a bad spider gear.  One tooth can cause a problem.  This one didn't make noise, at the time, but it would have, if I left it in there after a rebuild.   

I found the diff animation on the interwebs.  It what goes on around a curve. (you probably knew that already)

Matt

 

Ugh. Given this and other things I've read in doing research I'm starting to believe this is my problem. In this photo above what is the indication its gone bad? Is it the wear on the sides of the teeth? Wouldnt they have wear there normally? Now I want to check my diff internals. This weekend perhaps. Fun times.

Thanks!

[Einspritz]

Look in the blue manual, there are pictures of the wear.

 

I looked at the video again, have you checked for grease in the CV joints? You can do that by removing the large clamp and popping off the boot to look inside. Hopefully you have the clamps with the screw, otherwise you'll need new clamps.

 

Also, when you rattle the muffler... I see that the primary seems to be bent.. that's a straight pipe. So, yes, it appears to be hitting on the tunnel. As always, adjustment and fitment is fiddly..... And soft engine and transmission mounts contribute to that.....

 

Sorry to put you through all of this.

 

 

 

[Pablo M]

2 minutes ago, Einspritz said:

Look in the blue manual, there are pictures of the wear.

 

I looked at the video again, have you checked for grease in the CV joints? You can do that by removing the large clamp and popping off the boot to look inside. Hopefully you have the clamps with the screw, otherwise you'll need new clamps.

 

Also, when you rattle the muffler... I see that the primary seems to be bent.. that's a straight pipe. So, yes, it appears to be hitting on the tunnel. As always, adjustment and fitment is fiddly..... And soft engine and transmission mounts contribute to that.....

 

Sorry to put you through all of this.

 

 

 

Dont be sorry! Its all good. Just a shame this car needs as much work as it does. And I just lost my job so can't be buying a bunch of parts (or a diff!), at least for a while.

 

The resonator is some janky "Turbo something" and looks welded by a monkey. Its an odd thing too, with pinched metal edges along its length. No surprise its not aligned correctly. Just another thing to the list, lol.

 

I havent checked the grease in CV joints. No outward signs of leaking but they could be dry. I'll see if I can open them up. The covers appear dry rot cracked all over but not fully compromised. I dont recall if they had screwed clamps. I'll try to post a photo.
Thanks for the help!