Okay, some of y'all gave me great advice before... So I have an 06 GMC Sierra 2500HD 6.0 gasser... I was driving to work and my transmission cooler hose blew. Lost fluid while driving and didn't realize it, saw smoke from where it was hitting the exhaust, came to a light and stopped, light turned green and the truck struggled to make it through the intersection, made it through and immediately pulled over. So I replaced the hose and added new fluids, ran through the gears while at idle and all of my gears work fine with no slips or hard shifts. Only issue is that I have no reverse, I put it in reverse and it acts as if it'* in natural. Before I drop the pan and change the filter this weekend what other parts should I look at. I read something about the servo pin or something like that. I'm really hoping it isn't the rear band lol. Thanks in advance everyone.

Also what would be the downfall if I keep driving it as is... Like I stated before no slippage no hardships just no reverse...

Should not hurt to drive. Sounds like the band may not be applied.

Thanks, I know you pretty much have to drop the transmission to change the band I believe, I can drop the transmission myself. How hard is it to change the band?

When you say the band, are you talking about the rear main seal? Also can anyone point me in the right direction of ordering a band.

Whoa! We don't know what it is yet. Are we sure it'* in 'R' ?
The band is applied by a servo. Is it stuck?

100% sure it'* in “R"..... When you put it in reverse it rolls forward maybe an inch like when you put the truck in park or neutral, and neutral is neutral. Does nothing but revs up, I read up on the servo wearing down over time.... Is there a way to get it unstuck if it is besides dropping the pan and messing with it?

Okay a little update, got home from work and was messing around and found out that the truck goes forward in neutral and very slowly and I mean very slowly inches it way forward. Still no reverse, it feels like the truck goes into park when you put it in reverse. It'* too dark right now to crawl underneath to look at the shifting cable, but I did read somewhere that it could be the C-1 clutch. Idk I'm off tomorrow so I'll have all day to investigate.

Sorry for the confusion.... When in park it very slowly inches it way forward... In neutral it goes forward like it'* in drive. My fingers wrote faster than my mind lol.

I believe my forward clutches are stuck together, done some more research and talked to a mechanic buddy and explained the symptoms of no reverse and I can drive forward in neutral.