So I have an 89 Ramcharger W150 318 with 4wd. I have gone through 2 upper yolks on the rear drive shaft in 2 years. The first was the factory one, one of the sleeves for the u joint cracked open when I pressed the old ujoint out. The second yolk was from an 87 w250 power Ram with a 318 4wd. They were direct fit for eachother so it was no problem. I pressed a new u joint in and put the yolk on the driveshaft and it lasted for about 7 months before the truck started making very loud vibration noises like the transmission was going, and that’s what I figured it was. I planned on bringing it to the tranny shop a week later, but within a couple days of me going there the u joint finally let go and blew the yolk apart. Now I know there’s nothing (immediately) wrong with the tranny. Another thing to add is I have owned this rugby 5 years now and changed that particular u-joint at least 3 times (besides the new u-joint with the new yolk) and I was just wondering where I can find another yolk. To specify I need an 89 4wd without overdrive upper driveshaft yolk. It’s 29 spline like all late 1986+ Ramcharger’s use. And also another thing, could there be something causing the serious need for u-joints all the time. My truck isn’t lifted so there’s really no added stress to it.