Can this truck be flat towed, 4-down, behind an RV?

[DavidP2001]

The vehicle is a 1999 GMC Sierra 1500, 4WD with the push button 4WD engagement to the left of the steering wheel.  I can hold down two buttons simultaneously and put the transfer case in neutral.  The owners manual says it can't be flat towed, but if this is true, I don't understand why not?   I know later models with the same push button 4-wheel drive engagement can be flat-towed, but why not this one?  Thank you for you comments! 

[diyer2]

Maybe wrong.

My guess is the auto transmission prevents it from being towed flat. If you remove the drive shafts it would work. Towing with the drive shafts in place causes the transmission to be engaged or spinning. It will not spin fast enough for the trans pump to lube the trans. 

[reardiff]

isn't that the reason for having neutral setting for the transfer case? I still have my manual for my 2003 which should be the same as yours and there's a section in there specifically about dinghy towing with all four wheels on the ground. It says you can if you put the transfer case in neutral. Even has a picture of a car being flat towed behind an RV. 

 

[newdude]

If you use the 2000 manual https://my.gmc.com/content/dam/gmownercenter/gmna/dynamic/manuals/2000/gmc/new_sierra_1500/2000_gmc_sierra_owners.pdf

 

The 1999 manual online from GMC for whatever reason is all about the old body classic 1999.  The 2000 book covers the new 1999 Sierra correctly.

 

[DavidP2001]

Thank you, I greatly appreciate your comments!