thumping sound in front end, questions???

[struggle]

I have a friends car over hear tonight and it is making a thumping rotation sound in the front end.

Wheel bearings are tight.

No play in front end suspension.

Tires a year old,I rotated them front to back,no change in sound

Car is a 4 cyl. 5 speed Accord LX 99 vintage

Noise is very apparent at lower speeds, no differnece when braking or pulling E-brake.

Noise is present in any gear or neutral.

Pitch does not change when swaying the car back and forth loading one wheel or the other.

I see there is a center carrier bearing on the left side axle assembly, do these normally have any problems?

I lifted the car up and ran it in gear and checked outer bearings with a stethoscop and the were as silent as a baby in a mothers arms.

The mid bearing has noise in it but did not sound thumping and is also attached to the engine.

Car has 110,000 miles

Is there any known problems on these for this type of noise

It is a rotational noise for sure in relation to wheel speed. I just do not want to throw parts at it. Noise seems centered to me while driving it.

Do the five speeds have any trans issues with bearings? I also can feel a slight vibration in the gas pedal in relation to the noise

[powerplating]

The thumping noise is more then likely a drive shaft

[whoodie]

I have the EXACT same symptoms. I'm putting on a fidanza flywheel and Exedy clutch soon. I plan on checking the inner and outer driveshaft joints when I have it apart. I lowered my car a few months back so I wouldn't be suprised if the 130k mile old driveshaft joints are giving me the finger.

[rmsmith]

I have a similar problem in my 91 accord. a speed related thumping noise. however mine only occurs after about 10 or 15 min of driving and only in gear and accelerating. Been told by several people that it's the motor mounts. Those are getting replaced, I've replaced both cv axles and those didn't help. i'll post back here if the mounts help.

[rmsmith]

Me again, writing back. It was my front motor mount(torque strut) it was cracked so i replaced it and Good as new so far.

[jeffcoslacker]

Generally carrier bearings will change their tune when loading changes (like abruptly going from accel to decel), and will make the most noise or vibration right at the transition from loaded to free (like just as you come up to cruising speed, or just as the clutch begins to disengage).


It's easier to feel in a RWD, because the length of the shaft amplifies the vibration, halfshafts don't put near the same loading on carriers.

I bet that's your problem, though. Can you loosen it's mounting slightly, and drive it a short distance, see if the nature of the sound changes? That might nail it.