What's that noise I get while reversing?

[Jeep Puller]

I've noticed an odd, rather subtle noise that only occurs when I'm backing up. I haven't had anyone around to listen for it and track it down while I'm reversing, but it sounds like a cross between a metallic rub and an electronic beep - like I said, it's an odd sound.
Does this sound familiar to anyone? What is this and is it indicative of a problem?
TIA

[VFRRider]

The Allison gives off a gear whine when in reverse, just the nature of the H/D beast it is. That may be what you are hearing.
Mike

[dmaxalliTech]

Jeep, lets get a listen to it when you come up to Grand Rapids in September for Diesel day. ;)

VFR, you should come too..

Diesel Day (http://http://forum.thedieselpage.com/ubb/ultimatebb.php?ubb=get_topic;f=17;t=000088)

[Jeep Puller]

Diesel Day, huh?
That sounds like fun . . . to me, anyway. The wife is still trying to accept my recently announced week-long wheeling trip to Moab UT in October. Michigan in September might just push her over the edge.
; )

The link doesn't work for me, though. Have another?