Driveshaft geometry

[B-Red]

I guess you are right Trevor. You get used to seeing lifted D2s in MOAB they become stock lol

My D2 is 2" lift. Still running with the rotoflex. I did replace the ujoints though and the pro shafts as needed. Still stock, not beefed up probshafts. Greasing is important to prolonging their lives.

[Red90]

Here is a good series.  If you ever want to know how the insides of gearboxes work, this is the channel.

[Matt H]

A note on greasing.

Greaseable U joints are fine. They work very well and are, of course, serviceable. But beware the temptation to get carried away with over greasing anything (U joints in particular) as you can have too much of a good thing.

U joints that are over greased invariably fail. If you pump grease past the seals and grease comes out, water and road/off road contamination gets in. This will reduce the life of a U joint faster than anything else. That is why you will find non serviceable U joints on many new vehicles.

When it comes to grease, if a little is good, more is not nesasarily better. 

My 2c.

[Red90]

IME, the greaseable joints do not last as long as the non-greasable ones.  The greaseable ones tend to have much lower quality seal styles and let dirt in easier.  I don't think I've ever lost an OE brand non-greaseable joint.  Ever OE greaseable one I've used is dead within 3 or 4 years.  I may or may not play submarine more than the average person.

Lot of interesting info on part 2 of the videos above on seals and end play.

[Red90]

The newest episode in the Weber auto series goes over diagnosing u-joint faults.  It is quite interesting how little wear a joint can have before it is out of spec and causing trouble.

Another interesting tidbit at the end was that Jeep (and possibly others?) have starting using staking to secure the caps, making it not possible to replace u-joints!!!  Insanity.

[Matt H]

I'm not suprised. The industry has been heading that way for some time.

When was the last time you repaired a starter or an alternator?

[Trevor]

That Weber Auto U-joint series is great. Ton of other good stuff on that channel too.