Did you read the fine print on their warranty? Lots of fine print. I put as much faith in that Dana/Spicer warranty as I do on my now irrelevant factory powertrain warranty. On a Jeep like mine with the Evo double throwdown suspension, I'd have no warranty on a new UD60. Because I changed the mounts on it, it is now "modified" and the warranty from Dana/Spicer is void. This was a big deciding factor is selling my new in crate UD60 axles and buying Dynatrac XD60 front/PR80 rear axles. The Dynatrac warranty is a 1 year, and during that year is absolutely the best in the business.
Also, here is the BIGGEST problem with the Dana/Spicer warranty, "Product parts and components manufactured by others (such as, wheel seals and tie rods) arewarranted solely by their manufacturers and not by Dana. " So if your Eaton E-Locker fails, or any other part that is not specifically manufactured by Dana/Spicer, you must contact that company for any warranty, not Dana/Spicer.
And here is the excerpt from Dynatrac's warranty, "For a period of one (1) year from the date it is shipped from our facility, Dynatrac Products Co., Inc. (“Dynatrac”) will at its option repair or replace the products supplied by Dynatrac as part of the original axle assembly, kit or covered products that become unserviceable due to a defect in materials or workmanship". So this is saying that ANY part Dynatrac installs in your axle, is warrantied by them. The Foote/RCV axle shafts, Dana gears, ARB locker, etc. Whatever parts are installed in your axle, Dynatrac will warranty it themselves.