I read on one of these threads that anything over 600 ft.lbs. of torque will cause premature wear on the Allison transmission. Just looking at the numbers, I know that the Duramax puts out (supposedly) 520 ft.lbs. I realize that this is not necessarily delivered to the rear wheels, but if you have the Edge Juice, even on the #1 setting, you're sending another 100 ft.lbs. through the tranny. Right? That, on paper, is 620 ft.lbs., already over recommended amounts for the stock Allison. Should you go to the #2 setting, you're up another 20 ft.lbs. This is the setting where towing is recommended. I will be towing about 10,000 lbs. in the coming months and don't really want to be beating the snot out of the transmission. I towed the same trailer last year without the Juice and had no problems, just wanted a bit more power. Does anyone have the numbers on how much torque is actually going to the rear wheels with a stock Duramax?

450ish..........that seems to be the norm, don't go any higher than stage 3 with the stock trans.

The stock Allison seems to be good for 650LB/Ft or so rear wheel TQ in most conditions. The TCC actually seems to cut loose somewhere around 700lb/ft +/- 50 lb/ft. From there, fifth gear is also a weak link, but I have not tested to see at precisely what level this one cuts loose.

Edge Juice level 1 and 2 are decent towing levels. 3 is fairly safe if driven easily, and 4 is questionable at best.

450ish..........that seems to be the norm, don't go any higher than stage 3 with the stock trans.
I hope you are wrong! Because I have been at about 700 rwtq for the last 70,000 miles. Hell; the stock tranny lives with 400+ from the factory. :eek: I would bet that 70% on this site hasn't seen less then 450 rwtq since they drove the truck off the lot. :D

Many here has dyno proven numbers of 400 rwhp, and 700 rqtq on a stock tranny for 10`s of thousands of miles with little or no issues. However, you need to learn how to treat the truck/tranny with these numbers.
I run the Quadzilla Stealth 135, Banks monster exhaust, and AFE stage II air intake with a stock transmission. This setup gives about 380-405 rwhp, and 675-750 rwtq on average.

The tranny can handle anything under 400 rwhp as long as you back out of the throttle going into 5th, and taking it easy while in 5th. As for torque, I am not sure! But it is the torque that kills the tranny. In an 8.1L big block, I would think the transmission could handle 450+ rwhp, because the torque is so much lower then the Duramax.

Looks like John got a hold of this about the time I started my reply! ;)

When towing my 10,000# TT, I do back the power down to the 110 hp level, and as long as I don't use cruise control, and I take it easy, I don't have problems unles in the mountains. At which time I back it down a little lower. Cruise will cause the transmission too be zinged or worse yet limped pretty quickly on hills. The truck tries to stay in 5th gear, and before you know it, "ZING"

Would larger tires increase the stress on the Allison in the lower gears and cause problems below the levels your saying its capable of handling? Going from 245's to 285's is a 7.6% increase in ratio.

As an addendum to my original post, I went back to the '04 Silverado brochure, and there on page 7 is a box identifying available motors with their respective horsepower and torque outputs. I see that the Duramax with the 6-speed is rated at 520 ft.lbs. and the same motor with the Allison comes in at 590! What's up with that? I seem to be finding more questions than answers.........

As per my service manager, if you have had the LLY reflash for the idle surge PIP3129B??? you will actually be at 605 ft.lbs.

As an addendum to my original post, I went back to the '04 Silverado brochure, and there on page 7 is a box identifying available motors with their respective horsepower and torque outputs. I see that the Duramax with the 6-speed is rated at 520 ft.lbs. and the same motor with the Allison comes in at 590! What's up with that? I seem to be finding more questions than answers.........
Different programming for the 6-speed, since GM insists on putting this dual-mass flywheel in these trucks.....Which, as you may have already read, is 1 small step above garbage....Thankfully, there are ways to fix it...