After 450,000 miles owning Duramax trucks, I'm here to tell you...It's no myth.
It depends what you call maintenance and how much you pay in parts/labor to get it done.
I know 2 people (brothers) that run expensive synthetic oil and then do oil/filter changes at 3,000 mile intervals. Runs transynd fluid and does a flush and fill on that every 10,000 miles &at the same time transfer case and differentials are done. One of those two guys does all brakes every 30,000 miles, while the other waits until the indicators makes noise. Both of them do all 4 new loaded calipers, rotors, and a flush. They both do new master cylinders at 100,000 miles, you know the 100,000 mile mark, where every hose innthe truck gets replaced? Every hose. No, they don’t do any of their own work trucks- everything is done at the dealership.
I am pretty good friends with one of the brothers, and he was bragging the other day about his truck breaking the 300,000 mile mark and he is waiting till his brother decides which new truck they both will buy (always matching trucks- idk why) and will replace his. I think his brother was just waiting till he hit the 250K mark, a few months away still. They never used to keep logs until they met me, but They have with these trucks. I got him to total up the cost of all the work done. Now his brother hates me more than before because he realized the amount of money spent and is starting to think about eliminating a bunch of the pm stuff on the next truck.
Granted those two are over the top. But certain things are there for average guys who don’t get carried away but dothe recommend stuff thats not really needed on modern cars. Remember our standards were from 1940’s cars- remember tune ups of file and adjust points and clean and adjust spark plugs every 3,000 miles when you are doing an oil change at same time?
In the fuel/oil company fleet I was wrenching at for years- all out pickups before the dmax trucks cane out had 4l80e or 4l60e depending on engine, except 3 were manual trans by special manager request. We completely understand quit doing transmission oil/ filter changes. Except for a couple trucks that managers and owners owned and our parts truck, every truck broke 100,000 miles a year. We had many trucks that were ran till it died on the route and brought in on a hook and the driver moved his stuff to a new one prepped and ready to go. All those were over the 300 mark. The ones we didn’t want down time of the tow truck and driver moving his junk over mid shift, got replaced around the 250 mark. Of hundreds of these trucks, only one broke down and got towed back over trans failure. Out of interest, another mechanic bought it for the $200 and sent it into his uncle’s transmission shop. $200 with no discount and it was on the road. He still has it last I heard as a beater rig and when his tesla is in the shop. Over 300,000 as of this February when I saw him last and the trans is still happy. His uncle did a new filter, and added a couple quarts in the repair.
My wifes 01 suburban was one we sold with just over 210,000 miles. I did get nervous towing a tiny camp trailer up to big bear when I met Big T the first time and he brought out his scanner to use because trans temps got hot first time ever but not over 210 iirc. It had 202,000 on that trip. We dumped the rig because the a/c was messing up (compressor) and I knew from experience we wer looking at a couple grand to do it all again- I couldn’t do the labor myself at the time, and a few trinkets in the truck needed help like front seats recovered etc. btw, never a spark plug pulled on that engine.
I am 100% convinced if you are going to dump the truck at 350,000 miles- just leave the transmission alone. Really heavy frequent use, ok that’s different. But most use it like a car or haul things that are bulky, maybe tow a small boat or snow machine.
ok, new post popped up and woke me out of my old man ramblings. Gotta re-read that and respond
