2 u joints in 3 weeks

[lowrodderchev]

Hey guys 3 weeks ago the u joints on the transfer case pretty much exploded they were discolored so I assumed it was from lack of grease and they were on the truck when I got it so I replaced them and the ones at the axle yesterday I notice a bad vibration and I had another broken u joint any ideas thanx

[lowrodderchev]

some photos of the damage hoping its just a bad u joint

[68Timber]

What brand are they? I was thinking cheap imported crap until the last picture.

[Irish1941]

That's a Precision brand. Chain store junk...good for bone stock street truck. And they can be bad right of the box.
That must be the 1st one that broke first as that one has been in there a while with no grease.
Use Spicer and avoid the zerk fitting greaseables.
Looks to me like front shaft let loose on you
Maybe driveshaft is bent? Worn yoke?
What yr is your truck?

[lowrodderchev]

75 blazer driveline still good I made a huge mistake and use the wrong grease not sure if that's what caused it both ends were pretty dry and what grease that on it smelled burnt

[Irish1941]

Think you figured it out yourself.
Safe to say heat killed it. Looking at the pix again, that nice blue part isn't supposed to be there. It got super hot! Wrong grease which melted out, cooked the bearing til they seized up and then it just got hotter til it snapped.
Remember to grease them before you drive the truck too.

[lowrodderchev]

Ok this truck hates me right now first the u joint problem then last week my system stop working then Monday it overheated possible blown head gasket left me stranded way to many times I either need to fix her or ditch her ��