U Joint Issue

My truck developed a vibration in the driveline. It got progressively worse over a few days making short trips. Initially, I could push in the clutch and release it and the vibration stopped. As the problem progressed, this no longer worked. My first thought was centered around the clutch and pressure plate, so I removed the inspection cover and checked torque of pressure plate to flywheel bolts. Also cleaned clutch with brake clean. This didn't show any improvement. I put the rear of truck on jack stands, and had Bud get in and run it in gear so I could assess where the vibration was located and found it to be at the ball socket/u-joint area. I found that the u-joint was not receiving lubrication from the transmission and had become dry. Pics show the condition. Note, the pieces pressed in the yoke and one side is too far inboard...

 

The u-joint is supposed to receive lubrication from "splash" from transmission, through main shaft rear bearing. My truck has the heavy duty Borg Warner T89 3 speed tyranny. After my overhaul of the tyranny early this year, it was discharging lube through the nose piece/front bearing retainer when filled to spec for this model. Transmission specialist, Earl Zimmer, indicated it's ok to run with lower oil level without harming tranny. What I did to lube the ujoint/ball socket was to drill and tap a 10-32 screw at 2 o'clock position near rear of tailstock, aft of Speedo drive gear. Then after reassembly of ball socket, added approximately 8 oz. of gear oil.

 

This tailshaft mod was done before or after the pictured U-Joint failure ? .

 

I did that after having this issue. I did find the problem before any damage was done. I was able to just burnish the surfaces of the trunnion bearing, lubricate, and reinstall.

 

The trunnions look passable but one of the caps looks brinneled, I'd not trust it .

Somewhere I have an Argentine U - Joint like this one but they didn't center the cross before machining it so as so often, it's useless from new .

Typical Argentina lack of quality control, why no one ever buys their 'A' Model brand 'F' products .

 

The discoloration, I believe, is because when I last assembled the trunnion, I lined generously with mystic red grease. No pictures of the cleaned up parts, but they cleaned completely back to polished silver metal. Pics are a little misleading.

 

I wasn't talking about the discoloration, there's clearly metal gone in one cap .....

 

Well, I see what you see in the picture, but in person all that cleaned off using solvent and the back of emery cloth. It's an 'optimetrical delusion

 

That's great ! .

Optical delusions are tricky don'cha know .