Front Drive Shaft Life Expectancy?
 

I have a D2 front driveshaft with non-greaseable joints. I put it in about 10K miles ago. I wonder how long I can trust it.

I used to have a double-cardan driveshaft with the massive H-block and the big, greaseable, Spicer u-joints. I thought it was a safe bet. But it let go after a short life and when it went, it took out the tranny pan and valve body, and cracked the transfer case -- kind of the same thing the stock shafts are notorious for. Why did it do that? I have no idea. It failed on the flange that bolts to the transfercase where the loop encircles the bearing cap on the first u-joint, but the shaft was also bent so that it was practically all destroyed. I was convinced to replace it with the stock D2 DC shaft because it is a good one and has less vibration than the bigger Spicer units.

But I got the non-serviceable joints with the new shaft. I'm running them rather than just tossing them and replacing them with greaseable joints. The good news is I've removed the catalytic converters so there is not the intense heat on the joints there would be otherwise. Still, I wonder how long those non-greaseable joints can last.

I believe that the original factory ones last long and over 100k. The heat I believe is minimal factor. I have one Disco and replaced the front shaft 3 times within 150k miles I guess because it has 32 inch tires.
The other 2 discos still have the original shafts with standard factory wheels and tires, one is 132k miles and other is 186k miles. But suggestions here is recommended that you have to change it once you get a disco.

Mine has the original non-grease able shaft and I'm at 75,000 miles on it. I was going to change it out someday, but it really seems fine.

Having owned 10, my estimate is probably between 130-160k. They start chirping before they let go. Based on my rebuild of two that were chirping, I would say the heat is a major factor. The grease was cooked in the bearings on the ones that were chirping.

Good catch!