My 01 tahoe will start, drive fine, but within a mile just stops moving, like a pump failure, no first, no r, nothing but a tach reading. I can then turn it off, restart and go back to normal... for another mile. I can repeat this in perpetuity it seems. Fluid levels are fine.

I think it'* worth noting that I, neglectfully, limped my battery to it'* last leg, having many "barely starts"(for lack of a better term) that left my clock reset and my 'tow/haul' mode engaged... I suppose these regular voltage spikes may have damaged something elecrtrically, at least it'* my best geuss.

Thanks for reading, any thoughts are greatly appreciated!

Do you have a new battery in it now?
Have you scanned/checked for any stored OBDII codes?

I just noticed this is your first post Dalen, so a big Welcome to the Forum as well !!

Thank you!
I replaced the battery today and the problem continued.
I have not had any scans yet, hoping to scan tomorrow but no codes are showing any dash lamps.

Generally when you remove both battery terminals, it clears all the codes and if you had some low voltage issues before, even after the new battery was installed, the transmission may possibly have to do a re-learn.
If you can safely drive it for a while with some regular driving, the shifting may improve. Watch for any dash lights that may appear.
Something else sounds like it'* going on though, and since an advanced pro scanner will be needed to read the stored codes including transmission codes, you may want to pay the diagnostics fee at the dealer or a good shop to scan it, and see all what'* happening there.
Edit in: Check all of your battery terminals for cleanliness, remove any corrosion, ensure they are on there tight, and look around/check ground wires /any electrical underhood connectors etc are tight.
I would also want to inspect/check all the transmission electrical connectors as well.
How many miles are on your Tahoe?, and have you ever had the transmission serviced with new filter/fluid?

It'* hard to imagine the transmission not moving due to an electrical issue. Usually if it has a problem it will go into limp mode and stay in 2nd gear

Hey, thanks for the feedback all! I've got 190k miles on it. I haven't done any services on the transmission since i got the truck at 150k miles, probably again neglectful on my part, however last week before this problem began my fluid was still nice. I notice some browning now, and the level has always been steady.

On a newer note, i went to move the truck this morning and at about 25 mph with no throttle it began to shift up and down before seeing the problem again.

i would agree with 75, slipping inside is normally not external or electrical. but if you got 190 i would feel lucky those transmissions normally only go 150 before needing rebuilt

I would definatly agree. It just seems odd that restarting resolves the problem, and i had 100% perfomance until just 0 all of a sudden.