drive line noise

[jeradsvx]

I have had a problem for the past few months and after driving my car on the highway yesterday it is time to do something about it. Here it goes:
when i am driving at speeds i would say above 40mph, when i am pressing on the accelerator i have a loud humming noise that i can feel in the car, can feel like it is in the driveline, doesnt shake the car but can feel the hum in the car. I have done the following to try to narrow it down, two new tires in the front, new alternator, new power sterring pump, crank pulley was replaced a 6 months ago.
When i take my foot off the gas at say 45 mph the noise is gone but once i start to give it some gas the noise comes right back, the noise is barley noticable at all at 25 or 30 mph. I wouldnt think it is the front wheel bearings they were recently replaced and i have had front bearings go before and there is no way that is has ever sounded like that, but maybe i am wrong. I would appreciate anyones input on this.
I thank you all for your help
Jerad

[msvx95]

I've got humming noise but I think it's my tires.....My tires have maybe 10,000 on them, but they are summer ones and they sound terrible.....My dealer told me awhile ago I could have a bearing going bad in the front, but the car drives fine and the wheel doesn't shake.
I'm curious too what the noise could be...mine and Jerad's.

[TomsSVX]

if it is a noise under load, sounds like carrier bearing in one of the differentials.... This means that the ring/pinion are probobly worn out of spec too. So, best bet is to try and figure out if it is comming from the front diff or the rear... I suspect the front because it carries more load than the rear and is suspect to failure more often.

Tom

[chitownsvx]

My differential before I changed it i could feel the lil vibration and hear it also. I changed the rear differential and now it's gone

[jeradsvx]

i have a spare front diff that is good........how hard is it to change it out.......
thanks
Jerad

[TomsSVX]

gotta drop the trans and take it apart... I would not recomend a novice do this unless they are fully ready to break something

Tom

[chitownsvx]

yeah I had the shop do mine, I know I didn't want to tackle it.

[NiftySVX]

Changing the front differential is a huge pain. It requires special tools, an almost complete transaxle dissasembly, and to make things worse, the ring and pinion gears are out of production. They must be replaced as a set, but that doesn't really matter because they are discontinued. If the front diff went away, or you the backlash is out, it's time for a reman tranny from subaru. I've done this on my car, and, unless you can carry a 300 pound transmission out from under the car and have a really good understanding of transmissions and extensive special service tools, I would take it to the shop.
Good luck.

[TomsSVX]

its not that bad.... it just difficult and its hard to be confident in your work the 1st time around

Tom