The most talked about, no, the most complained about item on the class leading 3.0 Duramax diesel is the oil pump driven by a wet belt. The wet belt has been round for several years but when it came to the all-new LM2 Duramax, the people lost their minds. It is a relatively odd design, whereas the belt is in the engine oil and is driven by the crankshaft to turn the oil pump. First thoughts are that this belt will slip or break or even disintegrate. That has not been the case in over 3 years with zero known failures. So, how long does this belt last and what will it cost? Let's break that down.
Maintenance Intervals - not all the same - But the belt is
In 2020, the 3.0 Duramax diesel came out in the light duty 1500 Trucks. The engine designation at that time was LM2, this is the RPO (Regular Production Order) that GM generated for the engine. At this time, the maintenance interval was 150,000 miles and the job requires the removal of the transmission.
In 2023, the LZ0 engine came out and the maintenance interval jumped to 200,000 miles. You know what didn't change? The belt part number. In addition to the LZ0 engine getting the longer interval, ALL 2023+ 3.0 Duramax engines now have that maintenance interval. Yes, even the LM2 in the SUV's.
What's the cost of the belt replacement?
LABOR - The job is not for the weak, but it isn't as bad as it sounds. Yes, the transmission needs to come off the back of the engine and the rear plate needs to come off to access this belt. When looking up labor times from ALLDATA, it is noted they call for 9.5 hours of labor to do the job, however this appears to be incorrect. The labor rate to do a rear main seal (where the rear plate is) is 2.2 Hours PLUS Transmission removal which they state to be 12.2 hours. So, the real labor amount is 14.4 hours. Even that can be argued as that is just for the seal, where the tech would then need to remove the cover plate and then the belt. 15 hours is a fair number, I believe. If we take a labor rate of $175 per hour, which may be more or less than your area, the labor cost comes to $2625
PARTS - The parts required are just basic lower cost gaskets and bolts. The flexplate requires 8 one time use bolts and every part removed will require replacement of the gaskets. The exhaust is removed as is the backpressure valve. These parts out of the way help to access the starter and then the transmission can start to be unbolted and removed. yes, I skipped quite a few steps but I am trying to paint the picture of how the stack of gaskets and bolts add up. Oil and filter will need to be changed and the transmission fluid will need to be topped off, requiring a special tool to get the fluid in. The highest priced part will be the rear cover plate which absolutely should be replaced and not reused ! The belt itself is under $25. Parts prices are RETAIL PRICE as of 9/9/2023. Taxes not included. Total Parts cost $348.69
$3000 is a lot of money
Yeah, it's hard to ignore that number. Let me remind you of the great power and fuel economy these engines provide. You also do not need to replace spark plugs and wires like you would on a gas engine, no fuel service services or carboned up valves from direct injection engines like you will find on the gasoline engines. An average vehicle is driven 15,000 miles a year so that means this service will need to be performed every 10 or 13 years. $25 a month is what this will cost you, if you save from day one. On a recent youtube video, one person even commented, "do you really think the transmission will last 200,000 miles? Just do it at that time." They are absolutely correct with their question. We all hope the transmission will last beyond 200,000 miles but with the temps they are run at, that's unlikely, but that is for a different article.
Parts list shown is what was used in a most recent belt replacement - some parts may or may not be listed, this is for entertainment use only and should be verified with your local dealership using your vin number.