Sheared Cam Gear Dowel - Chevy and GMC Duramax Diesel Forum
01-04.5 LB7 Duramax Powertrain Discussion of components that are directly involved in the power production and all that is needed to get and keep the truck moving . Engine , Transmission, Etc.

 
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post #1 of 4 (permalink) Old 01-13-2020, 01:31 AM Thread Starter
 
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Question Sheared Cam Gear Dowel

Picked up another Duramax to flip believing it was just injectors and injection pump. come to my surprise all but 4 pushrods are bent. Probably a stupid question but is the LB7 an interference engine.Second, with 400k on it should I yard the motor and trans out and rebuild both? Any help would be greatly appreciated as I mostly work on cummins and Detroit/MTU 15+ liter motors and have little experience in these small trucks.

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post #2 of 4 (permalink) Old 01-13-2020, 06:59 AM
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The Duramax engine is DEFINITELY an interference engine. Have you already determined that the cam gear spun or is that just what you are figuring? Has someone been into the engine recently-head or valve work- that could have caused things to be out of adjustment?

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post #3 of 4 (permalink) Old 01-13-2020, 10:02 PM Thread Starter
 
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No im the first one in 100k miles to open up the engine. Cranked it over while watching the valvetrain and pushrods are stationary. so either cam gear or idler gears are sheared, or cam broke up front. So at the very least I need to pull heads and redo the valvetrain

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post #4 of 4 (permalink) Old 01-14-2020, 06:04 AM
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You can look at engine information with a scanner and see if you have crank and cam signals to see if they are both turning before you dig into taking the front cover off if you wanted to. But it sounds like you're gonna be going into the engine anyway, so I would start with the front cover and go from there. But its definitely no Bueno if the valve train isn't moving, there is a pretty major problem somewhere

Name: Matt
ASE Certified, former GM Parts guy
John Deere Service Manager

Play Truck - 2002 LB7 2500HD Crew Cab Short Bed
Daily/Tow Rig - 2006 LLZ 2500HD Crew Cab Short Bed

SOLD - 2007 LBZ 2500HD Standard Cab Long Bed
SOLD - 2006 LBZ 2500HD Crew Cab Short Bed
SOLD - 2004 LLY 2500HD Crew Cab Long Bed
TRADED - 2002 2500HD Crew Cab Long Bed
SOLD - 2001 2500HD Ext. Cab Long Bed
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