I think the normal service for the U-joints is every 15,000 miles. FWIW I've been greasing my slip yolks and U-joints every 5000-10,000 miles (max) for decades. As the U-joints and slip yolks build age/miles on them they tend to sling the grease out quicker, so the greasing intervals should become shorter IMHO. Always regrease ASAP if you've driven through very deep water.
Steering knuckles you "top off" via the knuckle inspection port when the grease level is low, but then you don't want to to fill them 100% full (to allow for expansion when hot). Ditto: if the knuckles have been submerged they should be pulled off, cleaned, and repacked.
Wheel bearings ~every 30,000 miles for normal service IIRC, or immediately if you've driven through deep water that submerged the axle housing/hubs. Most people IME however go well beyond 30,000 miles for wheel bearing service assuming no extreme use/conditions.
The zerks on the slip yolks and U-joints should not be in an awkward position if installed correctly. IME key when greasing most of the U-joints is to position the U-joint (by turning the driveshaft) so the zerks are pointing upward somewhere between 10-2 O'clock then approach the zerk fitting by reaching up and over coming down from above onto the zerk using a flexible hose on the grease gun. If the vehicle in on a lift, axles drooping, that gives you more room to get inside the U-joints.
Others will chime in if I'm too far off.
Still a lot of information in the FAQ section, Post #6, Maintenance
The Frequently Asked Questions (FAQ) for the 80/LX450 series tech section continues to be a work in progress. The goal is to have links in the below to other threads and tech articles. By having these linked, instead of pasting the text, the threads will remain live. The live threads can...
forum.ih8mud.com
Here's a couple of schedules, one for the 80 Series (normal service) and one for the 70 Series just for comparison (click twice on the image below to magnify)
