Cracked drive pulley

[Barrington]

Cracked belt drive and power steer pump pulley. Yep, I removed the belt and found both pulleys cracked, srt10
Any comments why?

 

[Nick_rp]

Age and heat. Not saying its common but for metal to warp (dosnt look cracked) like that its almost always age and constant heating and cooling

 

[Barrington]

I have just removed the power steer pump, pulley also cracked,
Truck has only done 33,000 klms
first post of main drive pulley,
Photos below is power steer pulley.
These are fully welded both sides!

 

[Nick_rp]

Pulleys are made from a single flat piece and rolled and brazed together. Low quality pulleys will obviously not last that long or maybe the manufacturer had a new guy on the line that didnt know what he was doing. Either way, the only thing to do is just replace it.

 

[HemiLonestar]

Those aren't cracks lol...like Nick said, the rib surface is rolled around the pulley piece. That's the seam. Since it technically isn't one solid piece of metal, the needs to have that seam to account for thermal expansion/contraction. Over time the gap may spread a bit but it's fine. Stock replacements will have the seam (albeit might be narrower being new) as well. Here is a crank pulley like yours and a PS pulley you can see the seam at the top.

 

[Barrington]

Thanks, I have ordered one of each pulley, the power steer one seams to be worse of the two.
I’ll see how the new pulleys are.