My relatively new rear driveline already needs new u-joints.

I believe I bought Napa Gold brand last time.

Any recommendations on best brand and supplier ?

Buy Spicer. Never look back.

I worked at NAPA in college. I blew up many of their U-joints. Parts store U-joints are all garbage.

What digger said. I buy mine from drive shaft shops. Many Napa gold parts are made by Spicer, but I'm not sure about u joints.

I understood that Napa Gold were actually Private label made by Spicer

Maybe I should stay out of water and lube them more frequently.

safe to say the ujoint at the rear pinion is what failed? Too tight of ujoint straps will cause them to fail prematurely also.

You might want to turn your Boost down a little!

...and stop re-loading at work!

You could use Tom Woods Gold Seal joints...they not only guarantee the joint but also your driveshaft if they break. I just got mine rebuilt with them, so I don't know of their quality just yet. I'm sure Tom wouldn't put crap on their driveshafts.

There are some awesome joints out there. (CTM still make some? ) But as others have said, most of us will be happy with Spicer. If you know your part number, try 4wheel parts as well. Just make darn sure you got the one you asked for. They usually have good prices.