E46 Manual clunk from rear

Bradmax57

Bradmax57

Bradmax57

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Joined
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Newcastle upon Tyne
Recently picked up what i thought was a bargain E46 320i se, its an 03 plate with 60k with the same owner from new, orient blue with grey leather and 17" 7 spoke alloys, apart from a deng in the wing and some corrosion to the alloys inner spokes its in top condition all for 4k, my only concern is a bit of a clunk coming from rear diff area when changing gears, its not a hideous noise but i am concious of it, just wondering if any e46 owners have had similar experiences?

Ive read about subframes etc and also bushes going but would like to know where to start looking
 
Thats suspiciously cheap for a car of that age and mileage. I do hope you are not about to find out why buying a cheap BMW is a bad idea.

Is it a proper THUNK or a metallic chink? The propshaft centre bearing can wear and this will give you a 'chink' sound when applying power after a gearchange, although you can usually only hear it during slow speed manevours.
 
erm its more of a deeper noise tbh so im guessing a thunk, but at least webuyanycar.com offered me £750 more than i paid haha, ill get it checked out
 
paradigm said:
If its only happening when changing gear, I'd be inclined to look at the prop donut first.
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yes it only does it when changing gear, good news is because i got it pretty cheap i dont mind spending a little bit of money on it plus my mate owns a garage so can get stuff done basically at cost, failing that it can always go through the block :)
 
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You need a mate to look under the rear of the car. With the handbrake on apply a little drive in gear via the clutch and see where the movement is. I'd suspect perhaps a swing arm bush is gone, or as mentioned the central prop support may be going (although I doubt it as you would feel significant vibes through the car as well).

Look for movement in the swing arms and/or diff. Being an 03 plate the diff mount areas to the boot floor should be good but the bushes there can still go. ;)
 
Fido McNasty said:
You need a mate to look under the rear of the car. With the handbrake on apply a little drive in gear via the clutch and see where the movement is. I'd suspect perhaps a swing arm bush is gone, or as mentioned the central prop support may be going (although I doubt it as you would feel significant vibes through the car as well).

Look for movement in the swing arms and/or diff. Being an 03 plate the diff mount areas to the boot floor should be good but the bushes there can still go. ;)
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Joe T said:
Propshaft donut is a distinct possibility.
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Are they both big jobs? £ wise??
 
Sounds exactly like the symptoms mine had when the subframe pulled through the rear floor. However as has been mentioned yours is a 2003 plus only a 320i so this is very unlikely. You could check the diff mount and subframe bushes, you're best off taking it to an independant where they will be able to see exactly what the problem is. It could be something as simple as the exhaust hitting something when you change gear.
 
Wicksta said:
Sounds exactly like the symptoms mine had when the subframe pulled through the rear floor. However as has been mentioned yours is a 2003 plus only a 320i so this is very unlikely. You could check the diff mount and subframe bushes, you're best off taking it to an independant where they will be able to see exactly what the problem is. It could be something as simple as the exhaust hitting something when you change gear.
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Tbh i didnt notice it this morning...... but i'll get it looked at and luckily i know a great BMW specialist locally
 
Bradmax57 said:
Are they both big jobs? £ wise??
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It is unlikely to be the prop supports else you would feel vibrations back through the shell as you drive along, particularly at higher speeds. You have whats called a donut rubber where the prop meets the gearbox, they can become perished and fail, but last around a decade. The other prop support is whats called the central prop support which is mounted a couple of feet behind the gearbox. I'd really rule those out as the vibes felt when driving would be easily more than enough to have got a mention in the first post I am certain. If I am wrong, fair enough but I don't think so. As for the diff carrier bushes, I'm afraid it is a relatively big job and certainly would go a way to explain why the car was cheaper (if the seller was aware).

Assuming you have an garage or (god forbid) a dealer on it, it's still going to be the best part of a day's work to change the diff carrier bushes. Incidentally, the swing arm bushes are a fairly straight forward job and may be mroe like three hours (approx maximum time) to replace. The main time consumer on swing arm bush replacement work is in removing the spent bushes from the swing arms and cleaning the bush location properly before putting the new bushes in. Old bushes can be a pain because the bushes surrounding alloy tube piece breaks down to a powdery oxide. You should replace both swing arm bushes, because sods law has it that if you try to economize and just replace the one, the other one will surely go soon after.

The last thing it might be (if you can see nothing moving under the rear of the car when the noise occurs) is an internal issue with the crown wheel inside the diff breaking up after an owner has been abusive with the car. Manifests itself in the form of a clunking between gears, particularly noticeable at slower speeds and when maneuvering.

Diff carrier bush replacement = 6 to 8 hours.
Swing arm bush replacement = 1 to 3 hours.
Diff internal issue = replacement diff + approx 1.5 to 2 hours.
Donut replacement or central prop support replacement = .5 to 1.5 hours.
 
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I had this with my e36, thought it was the prop guibo, but today found it its the diff mount bushings. worth a look.
 
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