This is true. A buddy of mine has Toyota mini-truck axles under his Samurai with 150:1 crawl ratio and has eaten 2 axle shafts and 1 R&P set that I know of with 35's. This is with the stock 65-ish hp engine. He couldn't keep OEM-level parts alive after putting on 37's. Off-roading also introduces a lot of stress on a drivetrain that street trucks just don't see. Lots of quick changes in weight distribution, grabbing and losing traction, getting tires wedged in crevices, etc. I'd say 35's are the working limit on a stock D44 under an Isuzu that gets wheeled. Anything larger and its a good idea to upgrade shafts and u-joints or get familiar with your local Pick-n-Pull. CTM stuff is probably the strongest and definitely big bucks. There are plenty of options out there that provide a big upgrade over stock without the CTM price. Alloy USA axles with Longfield Superjoints can be had much cheaper than CTM stuff and still carry a 10 year warranty.