Clunk from rear when put in gear or braking

bmw
323

#1

I can feel and hear clunk or a thump comming from rear when I put in drive…Shifting to neutral does nothing, also hear it when braking and when I accelerate quickly.


#2

Easiest thing to check is for something rolling around in the trunk.


#3

Also could be somewhere that the exhaust system is bumping into the body of the car.


#4

Can you repeat the clunk by shifting between reverse and drive? If you can, it might be a bad CV joint.


#5

Likely a failing joint in the driveline as the others post or one of the control arm bushings is failing. I don’t know what year the cars is but have someone else put the car into gear while you listen and look at each side to see if one of the suspension attachment points moves and makes a clunk…


#6

I know for sure my front driver side control arm bushing is bad …But the clunk is coming from rear.


#7

You have bushings in the rear, too. If one in the front is bad, why wouldn’t you suspect one in the rear is too? It went everywhere the front one did.

Your response strengthens my opinion that on of the rear control arm bushings is shot.


#8

If you car is front wheel drive, likely some loose suspension part in the rear like @Mustangman suggests above. Whenever you accelerate, even just shifting from neutral to drive, the back of the car tends to move down and the front up. Either motion could cause a noise if a suspension part had room to move. My Corolla makes a bit of a squeaky noise as I accelerate sometimes too, I expect it is from something in the rear suspension.

If your car is rear wheel drive and has a driveline with rear differential, most likely cause would be a bad u-joint or similar in the driveline.


#9

A BMW 323 is RWD with independent rear suspension. If its an E30, the trailing arm bushings or even the shock upper mount are likely bad. An E36 or E46 one of the control arm bushings - the fore-aft ones, is likely bad.


#10

I was thinking u-joints also…Could it be the sub frame? When I shift into drive, i shift then the clunk comes right after its not at the exact same time I move it into gear.


#11

Yes it could be the subframe bushings


#12

When my rwd truck develops play in a u-joint, I get a clunk sound in spades when I shift from N to drive. It’s very easy to test if a u-joint has play, from the underside of the car when it is on a lift. Just manually twist the driveshaft, there should be no play at all in the u-joints.


#13

BMW doesn’t use universal joints . . . they use flexible discs


#14

The BMW afficinados call those flexible disks “Giubos” pronounced JEW-bou

Silly name, silly part!

Lets put ALL the engine’s torque through a block of rubber right next to the exhaust pipe! “Jawohl, mein Kommandant”


#15

Doesn’t BMW use guibos in the drive shaft but CV joints in the rear axle half shafts?


#16

I clearly remembered it was spelled “Guibo” in all the literature I read, when I was still living in Europe

According to wikipedia, it’s a common misspelling . . . but in that case, even respected trade magazines and automotive textbooks all misspelled it

Every single of our instructors would spell it “Guibo” on the blackboard, with not one exception

Probably a very common mistake, like saying “Nucular” instead of “Nuclear”


#17

Yes, but they work wonderfully, don’t they? They’re durable, smooth and quiet, and give BMWs and MBs that silky smooth drivetrain that makes them so comfortable.


#18

Yup, that’s how I’ve always spelled it too, until I did a Google search and found the iu instead of ui. I always pronounced it Gwee-bo as well.


#19

You are correct…BIGLY!
:wink:


#20

This thread got me to wondering about an article I read about a drive line diagnosis & repair problem. The single u-jointed (at each end) prop-shaft car had a bad drive line vibration. It had been that way ever since a new type of transmission was installed. Turned out the cause was the angle of the driveshaft to the transmission output shaft didn’t match up to the angle of the driveshaft to the differential input shaft. Ideally, apparently, for the single u-joint configuration to work the tranny output shaft must be parallel to the differential input shaft, so the angles at both sides match up, even if the tranny isn’t at the same height as the differential. To solve this problem they made a custom drive shaft using a ball-bearings-in-cage CV joint. I was wondering, why go to the complication of a CV joint? Why didn’t they just use a double u-joint arrangement. Wouldn’t that work as well as a CV joint?