PLEASE NOTE: This information is for a 2007-2012 Toyota Tundra, second generation, 4x4, and specifically for the model year 2012. I do not know if the 4x2's need to have their propeller shaft re-torqued.
I noticed some threads that listed Propeller shaft torque, but they truncated the part that told WHICH vehicle EXACTLY that they fit. So I did a two day subscription to Toyota Information Systems, printed out the pages, and scanned them in to a PDF.
The sort answer is that Toyota refers to the (rear) propeller shaft
as the "propeller shaft" with drive shaft torque of 70NM or about 52ft lbs
Toyota refers to the "front propeller shaft"
as the "front propeller shaft" with a torque of 80NM or about 59 ft lbs
Considering that the maintenance guide just says "re-torque the propeller shaft," I think that it might only be necessary to re-torque the "Propeller shaft" (rear propeller shaft) with no need to re-torque the "front propeller shaft." Someone please correct me if this is wrong.
Some people think all you need to do is "check" the torque. You cannot just "check" the torque without first taking at least some of the torque off of the fastener with a ratchet or breaker bar. If you use a torque wrench to "check the torque," without first releasing at some of the torque it will actually increase the torque beyond spec. Torque specs are only valid on a moving fastener.
My guess for why Toyota requires a propeller shaft re-torque when towing is the loading and unloading of the truck put stress on the drive train such that it affects the bolts or perhaps the forces from turning when pulling a trailer put extra strain on the rear propeller shaft bolts. Unfortunately a shop or dealership is NOT going to do any of this work, not normally, and anything involving torque to a shop normally means an impact tool of some sort.
AFTER you have re-torqued the "propeller shaft" and "front propeller shaft" you might as well grease the grease fittings, there should be one per joint, front and rear. You have to hold the grease gun on them pretty hard, and try not to put too much, a squirts or a few squirts.
You are going to need a decent 3/8 torque wrench, something with a flex head, a long flex head 3/8 ratchet, 17mm? socket for the rear, 14mm socket for the front, a wobble extension, and enough patience to put the sockets on the fasteners carefully in a variety of positions as to not to strip the bolt. Release the torque on each bolt ONE at a time, and release and re-torque in a diagonal pattern. A headlamp helps illuminate things and I had the truck on a jack-stands, just enough to lift the suspension without really lifting the tires off the ground. Don't forget to use a grease gun with a LONG flexible nozzle or you will NOT be able to reach the grease Zerks!
Wobble extension or extensions:
FXWP1, Extension, Wobble Plus, Friction Ball, 1 1/2"
I know these are rather expensive, but a torque wrench like this is worth EVERY penny:
TECH2FR100, Torque Wrench, Electronic, TECHWRENCH®, Flex Ratchet, 5 to 100 ft. lbs., 3/8" drive
This torque wrench allows for switching between NM, Ft lbs, and others, and it vibrates, beeps, and shows the the reached torque when the wrench stops. It is possible that CDI, who makes or previously made these wrenches for Snap-on will have a similar model:
CDI Torque Products, America's Largest Manufacturer of Torque Equipment
Being a somewhat critical torque measurement, I would say not to bother trying to re-torque the propeller shaft with any torque wrench that is under $200 unless you have had it calibrated or unless you REALLY trust that wrench. You will have to have a flex head however, I do not think you can get it done without a flex head, and the smaller head on the Snap-on wrench will help out TREMENDOUSLY. Other alternative wrenches would include, Mac, Proto, Armstrong, etc.
Here is a company that is calibration company recommended by several manufactures, such as Armstrong, Proto, etc:
ANGLE REPAIR.COM...HOME PAGE. Torque wrench repair, calibration, certification.
Hope this information helps.