Duramax Diesel Serpentine Belt Seizure

An issue that we just had was the seizure of one of the serpentine belt idler pulleys which of course caused the belt to break, and of course we had our 28 ft travel trailer behind us. Only 30,000 miles on our truck. I heard a slight squeaking from day 1, but always attributed it to a squeaky belt, as there are service bulletins out about squeaky belts. Turns out it would be the best $46.00 + tax (approx cost, I assume this might vary dealer to dealer) a person could spend. This is for BOTH of them. The LLY uses 2 idlers, both the same. I believe that the pulley was defective from new, and took awhile till the bearing finally seized. I will probably start changing these every other year. I kept the one old, one and a universal one that NAPA had as LLY pulleys are not a stocked item and maybe the pulleys are not LLY specific but are the same across the Duramax engines. These, along with a new serpentine belt and the tools to change them are going to always be in the truck now.

Not an issue, but it’s official. 18 MPG ! I have an 04 1/2 LLY that now has the complete 2006 airbox assembly, up to and including the turbo mouthpiece, which of course I found out about in reading the magazine article about. The best that I was able to due previously was 16.5. I have a crew cab 4x4 running 265-75-16 tires. Next year it will be an oil cooler, probably the TD-EOC. As budget and time allows, I keep making it better.

Just as an aside, I run Bilsteins and larger sway bars from Hellwig on my truck. Makes it handle like a car ! Then I have a truck cap and an accessory called a “Bed Rug”. Regards, Dave C

A Thanks Dave! Just as a tip on the idler pulleys, usually they are good for about

Trackback(0) trackbackTrackBack URI for this entry

Comments (0)add comment

Write comment

security image
Write the displayed characters


Joel Paynton is an award-winning GM technician who specializes in Duramax fuel systems. He also does custom programming for any GM powertrain. Visit him on the web at www.payntonperformance.com.


maxxTORQUE in Print

(Available through Amazon.com)

Follow us on Twitter