1998 Transport Humming

[irgmfan]

My 98 has a humming that is road speed sensitive. Just replaced front hubs and bearing assemlies. I put it on jack stands and ran it. With a stethescope the hub bearing check fine. It seems like it is coming from the torque converter but with it being road speed sensitive and not rpm senstive I question that. It just started this week but seems to be getting progressively worse. I also, since changeing the hubs, occasionally the TCS and ABS lights will come on. I suspect it is one of the sensors in the new hubs but wouldn't thing it is related to the noise. Merry Christmas.

[LMP]

Hard to tell. Standard check list would be tires, alignment, hub assembly....but you've taken care of the last, at least...
Humming pitch is important...hub assembly frequency is rather mid range, say like 300Hz at 60mph, and changes with changes in direction, increases when turning on one side, decreases on the other...so these details are important.
Low pitch ..like 80-100 Hz rumble, can be cv joints....or transmission/differential output bearing....
Both of the above are speed sensitive.
High pitch buzz seemingly coming from transmission is frequent, inocuous, and seems related to pressure regulator, changes in intensity if one connects and disconnects vacuum from vac operated transmission modulator (not your model I think) and this one is rpm related....
...so....please add any of your findings to the list..it can help others.
Happy new year..

[irgmfan]

Sorry, Little late getting back to this, Turned out to be the hub bearing. Sometimes new parts are crap.

[LMP]

Originally Posted by irgmfan

... Turned out to be the hub bearing. Sometimes new parts are crap.

Indeed, my son and my brother both had to replace within days a newly installed hub bearing assembly, one a 2000 Grand Prix, the other a 2002 Montana.