reverse went out transmission whining
 

Okay. So I drove the truck from Alaska to California. Did great. Noticed a slight noise starting from the front end (maybe?) Thought it could be a wheel bearing. Haven't had any spare time to check it out. Today I came out and there no reverse, just make a whining sound. It goes forward but definitely no reverse. Fluid check on transmission dead on. Any thoughts? Where should I start?
Thanks
Steve
2000 blazer trailblazer edition automatic etc etc etc...

also should mention
 

Just did a complete engine rebuild. I'm a boat mechanic. Worked on tons of imports. Not a GM mechanic by any means. So any help will be greatly appreciated. I'm definitely not a transmission guy, and really don't want to be. But it's looking like I may not have a choice at the moment.

That generally means the reverse band is gone or the servo is shot. All in all this usually means a teardown and rebuild since you have to do that to get to the band. Probably quite a bit of clutch material in your pan too. It sounds like its time.

4L60E no reverse.
 

4L60E with no reverse are usually a broken driving shell. Technical name is reverse reaction shell. They operate reverse through 2 separate clutches, the reverse input and the low & reverse. The only band they use is for second and forth. You can replace just the reverse reaction shell with minimal parts. Where are you? I can hook you up with a parts warehouse if needed. A good trans guy might help on the side too. I'm here to walk you through it if needed.
Tranzman