IMO, its not so much what the truck can pull or what amount of weight it’s rated for, but the quality of brakes and breaking system on the trailer. If you look on our trucks there is no trailer weight limit. There is however a GVWR (Gross vehicle weight rating). My truck GVWR is 4990. With a class "C" license I believe our trailer limit is 15,000 lbs as per California law. I believe it is the responsibility of the driver to make sure he or she can stop their vehicle in time to avoid a collision. Unfortunately there's a lot of people out there that has no clue as to how much weight there pulling and how well they can stop there rig before it's to late. Here's a quote from the CHP.
" Towing and Camping Notes
Per Officer Mays at CHP commercial office in San Jose (408-
8483078):
Any Class C Driver (CVC12804. 9b3H) not for compensation can drive
any legal combination (not permit loads) of rigs as long as it is
no longer 75 feet including extremities (cVC35401b). 65 feet
is the limit if any one element is over 28 feet 6 inches long.
Maximum width is 102 inches or 108 inches with a compressed load
like tires.
The towing vehicle cannot be a passenger vehicle as defined in
CVC465 (including a motorhome) and must weigh at least 4000 pounds
empty. A pickup qualifies, even with a non-permanent camper
attached .
No single element can weigh more than 10,000 Pounds or 15,000
pounds with RV license endorsement (test), maximum rig weight is
26,000 pounds.
Any element over 3000 pounds requires brakes; 1500 pounds for
trailer coaches and camp trailers. (CVC242,635) Note definition of
a traller CVC630 and a utility trailer CVC666; those ARE NOT camp
trailers nor trailer coaches. Trailers are measured from the tip
of the hitch to the rearmost part of the body as described for camp
trailers in CVC242. 2 red lights and a red or fluorescent oranqe
12 inch square flag must bc used on any load that overhangs 4 feet
or more from the rear. All clearance lights within 24 Inches of
the rear of the trailer must be red. On boat trailers (sinqle boat,
designed for launchinq) only one set of side clearance lights are
reguired: amber forward-red rear combo liqht at maximum width
point.
No law prohibits riders in a trailer (as defined in CVC630) nor are
seatbelts required. They must have instant communication with the
driver (CVC23129) and an unlocked exit (CVC28080).
AB3518 Greywater systems for single family residences Act of 1992
specfically allows discharge of shower, lavatory, and hand dish
washing water onto the ground for irrigation as lonq as discharge
is at least 2 feet ftom buildinqs, 5 feet from water lines and 50
feet from lakes or Streams, l00 feet from wells. Kitchen sink water
is not allowed although the intent is to specifically not discharge
grease and food matter which whould attract flies and cause odors.
where children can contact the araa, shower water is not allowed.
Discharge must be on your property or campsite. No permits are
required. Discharge onto envlronmentally sensitive areas may
be prohibited by local ordinance. "
Attention: TDR Forum Junkies 
. IMO, you should through some Amsoil in that transmission and get your self an EGT and transmission temp gauge so you can keep an eye on things.
What all the guys are saying is worth listening to. Guages will enable you to monitor EGT and transmission temps. The torque converter and valve body are the weak link in the drive train of this outstanding truck. There are many out there to select from. Most rave about Diesel Transmission Technology's TC and VB. Bill Kondolay produces a fine product and has a support and installation network across the land. DTT TC/VB are on my upgrade list! Hard part is getting started. 
