I think even if the technical numbers are good...there are other things going on with the AAM-7.6ifs that have nothing to do with the numbers. I assume the chart is devised from math equations, and case flex is something that probably isn't accounted for in the chart. Even though it is larger...it does not seem as strong as the S-10 7.2ifs or the Dana 30 front axle used in many Jeeps. Not sure if its the weight of the H3, or just a bad design. I tend to think its the latter.
All of the other IFS axles across the GM line-up (S-10, K-1500, K-2500, K-3500) are basically different sizes of the same general design. They utilize a "vertical split" type of case, where two halves make up the bulk of the case, and they are all driver's-side drop units. Most have a CAD actuator for 2WD mode. I'm not sure if they are reverse rotation designs or not.
The AAM-7.6ifs is real bastard among GM front axles. Its only used in the H3 / Colorado-Canyon trucks and its design is very different from all the other GM front 4WD axles. It uses a traditional rear-load type case with a pan cover, (like most solid axles), rather than the vertical split case that seems to prevail in IFS axles. It seems to be closely related to the GM 7.5 10-bolt rear axle that came in many GM cars & trucks throughout the 70s and 80s, and the ring & pinion is cut for standard RWD use. Of course the AAM-7.6ifs is flipped around and running backwards. This is not un-common as all GM low-pinion front axles are essentially rear diffs spinning backwards. I don't think this is as big of a deal as many guys think it is...but forward power is being applied to the coast side of the teeth. Ford and Jeep address this issue with their reverse rotation Dana axles...actually re-designed to be spun backwards, (with teeth leaning the opposite direction)...but I seriously doubt if this has any relevance to the AMM-7.6ifs's reputation. A turd is a turd, and I don't think it would be any stronger if it were reverse rotation. Its got other problems.
In addition to the catastrophic failures the 7.6ifs is famous for...lately, it seems pinion bearings are failing at an alarming rate. Seriously...I got em lined up for repair. I don't have an answer, other than to install new bearings and pray.
