04 Sierra 1500 shake at certain speed -need help

[PJB1972]

1 1/8" OD or 1 1/16" OD?

 

I whipped out the ole dial calipers and they're 1.125 inches (1 1/8")

And they're the Injected plastic retainer type so they've NEVER been replaced in 315,000 miles.

Still are tight with no play... Hard to believe.

 

So I ordered 3 ACDELCO Part # 45U0108 {#12479126, 89029290} Professional U-Joints, 1 u-joint strap kit with replacement bolts and the Timken #HB3514 drive shaft center support

[PJB1972]

Rather than start a new thread, I thought I would tack this on here...

Long story short, I got my U-joints swapped out without much duress, But I was unable to get the center slip yoke apart.

 

(BTW - This is not my drive shaft, just a picture from the interwebs of the stub and yoke in question)

 

I dropped it off at the local drive shaft shop, and the tech told me that "the splined stub is a 30 tooth based on 31 and the yoke is 31 based on 32... "

(or something to that effect, the numbers may not be exactly what he said, the point being, they didn't match)

Which is why it was so hard to get it apart.

 

The rubber insulator around my center support bearing was shot. The bearing was still good. The tech stated that because this slip yoke could not "slip" (because the splines are mismatched), the stress was transferred to the rubber insulator, wearing it out over time.

I can believe that... but here's my question.

Why was this done in the first place?

This truck has 315,000 miles on it. 300,000 of them I put on the truck myself over the last 11 years.

That drive shaft has NEVER been touched! By anyone. Ever.

 

Have any of you guys heard of this happening before?

[PJB1972]

I bought a drive shaft from the salvage yard with a good center slip and a splined stub, got 'em swapped out.

Thanks for the help fellas!