Subframe noise

[Ian]

When people use solid rear subframe bushings, they often mention increased noise and harshness. What causes the noise/harshness?

Is it vibration of the metal bushing with the frame, or is it vibrations transmitted from the diff through the rest of the car?

Inquiring minds want to know!

Thanks,

Ian

[c.d.iesel]

all of the above

your loosing insulation isolation between buzzinig whirring parts

it does get nOiSY!!

[bracohen]

hmmm, could this be why my car is so noisy? I just bought it recently, still discovering everything. I've described it as sounding like a school bus on the inside. It's like a whiring, fairly high pitch sound that gets louder/higher pitch with more speed (although that was probably an obvious observation).

...or is the nature of an 02? I don't mind it, just trying to learn.

[eurotrash]

hmmm, could this be why my car is so noisy? I just bought it recently, still discovering everything. I've described it as sounding like a school bus on the inside. It's like a whiring, fairly high pitch sound that gets louder/higher pitch with more speed (although that was probably an obvious observation).

...or is the nature of an 02? I don't mind it, just trying to learn.

Ask the PO if there are any urethane mounts ANYWHERE in the car (other than just end links) ..this will answer the question.

[Retrogroucher]

Hey, Ian,

CD is right. A sound engineer could explain this better than I, but there's more potential for echochamber/resonance, especially w/o an interior and the sound deadening removed. On my Z Gremlin the N and V were augmented. Harshness was no different. Any drivetrain imbalance/misalignment gets unmasked-- I'll tell you about that sometime. It's nothing a little earlpug action won't cover.

Yes, you'll still be able to drive to the track.

No, take the e46 out on dates.

Happy fab'ing.

Mike

[Ian]

Thanks, all. I'm just debating running tubing under my cage to connect the back of the car to the front. Either bolt or weld or use bushings to connect to the rear subframe.

I can figure out the pluses, just trying to scope out the minuses!

Ian

[BLUNT]

hmmm, could this be why my car is so noisy? I just bought it recently, still discovering everything. I've described it as sounding like a school bus on the inside. It's like a whiring, fairly high pitch sound that gets louder/higher pitch with more speed (although that was probably an obvious observation).

...or is the nature of an 02? I don't mind it, just trying to learn.

this is more likely a noisy pinion bearing but who knows.

Doesnt mean its goibng to fail anytime soon. Ive driven the hell out of noisy diffs and they seem to just keep going

[bracohen]

this is more likely a noisy pinion bearing but who knows.

Doesnt mean its goibng to fail anytime soon. Ive driven the hell out of noisy diffs and they seem to just keep going

After a quick search I think you're right, thank you so much for the insight. I remember reading through some of the previous owner's threads and seeing something about a noisy differential.