5-Speed makes noise under load, maybe bearings?

[mschmud]

I have a '99 Cherokee Sport, 4.0L 5-speed manual transmission with about 72000 miles and original clutch. Lately I have noticed two different noises that it makes when under load, and they have been occuring more frequently lately--

-the first is a low gravelly growling noise that occurs sometimes during everyday highway driving, in fifth gear, when the gas pedal is pushed in to accelerate -- backing off the gas seems to make the noise go away.

-the second noise is a louder, higher pitched metallic clicking or rattling sound that only seems to occur when the engine is under heavy load, like going up a steep hill or pulling a trailer, especially in 4th or 5th gears. The clicking is constant but not regular or rythmic -- sounds kind of like something is loose and rattling around. Downshifting or releasing the accelerator a little makes the sound go away.

Does this sound like a bearing problem? I can't tell exactly where these sounds are coming from, either the engine or the transmission. It's possible that the second noise occurs at the same time as the first noise, but I'm not sure. The Jeep has always been pretty noisy, which I believe is normal, especially for the manual transmission models. I can't replicate the sounds when idling, it has to be under load. I haven't taken it to a mechanic yet.

Does anyone have advice on what to check?

Thanks,
Mason