MAINTENANCE ---who to believe?

My 2016 Chevy Suburban has 62,000 miles. At a recent Valvoline oil change, the tech said 1. Replace Fluid in Front Differential every 30K miles. (Never done!)
2.Power Steering fluid change every 30K miles. (Never done!)
3.Replace Fluid in RearDifferential every 30K miles (Never done!)
4. Replace fluid in Automatic Transmission every 45K miles (Never done!)
5.Replace fluid in Radiator every 60 months. (Never done! Haven’t had a radiator leak since the early 1970’s )
6. Replace fluid in transfer case every 45K miles; I did that …he showed me the myriad of tiny flecks of metal trapped on the magnetic plug.

The Chevy Owner’s Manual says Replace Transfer case fluid every 45 K miles, and replace Automatic transmission fluid and filter everly 45K miles. and change engine and passenger air filters.

So, who to believe??? Valvoline or Chevrolet??? YOUR THOUGHTS??

You even have to ask ? Me thinks the people who built the vehicle would be the ones to trust.


Chevrolet, not Valvoline. That’s Chevrolet owner’s manual, not a Chevy dealer. The dealer might try to accelerate work like Valvoline would.

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I think changing every fluid in truck would increase odds of going another 60k miles. Are you keeping it for next 3-4 years?

Here’s the schedule, looks like changing every fluid every 45k would pretty well cover it:

While it doesn’t list differential fluid, I’d do it, too.


I’m pretty sure your car has electric power steering and not hydraulic, so there isn’t even any fluid to service. Unless they can show you a sample…

Just based on the idea that they tried to sell you a power steering service that doesn’t exist on your car, I’d not trust them.

Sometimes dealers see things that the manufacturers don’t but I don’t know about Val online and if they are any better than the other quick lubes. At our initial Acura new owners gathering the service manager emphasized changing the rear differential at 10,000 then with trans fluid changes after that. So I did and change the trans, transfer case, and rear every 30,000. It is really pretty cheap compared to the replacement cost. For your never done maintenance, it’s late but maybe not too late. I’ve never changed power steering fluid though except as required with a pump replacement.

My mom took her car to valvoline for an oil change a few weeks ago. They said the car had a “severe” oil leak. I’m guessing maybe the last person who did the oil change left a bit of a mess. The car never drips. I checked the oil the other day it was still at the full mark. I’m no mechanic but even I can see valvoline probably aren’t the guys to consult with.

One thing I find interesting however is when your manual says something like “the transmission fluid is good for the life of the transmission”.

Not familiar w/your vehicle’s config, assuming it is similar to my 50 year old 4WD truck with locking hubs, so when you are driving in 2WD mode the front diff isn’t doing anything. If so the front diff fluid change could be delayed well beyond 30K if 4WD mode seldom used. My truck’s front diff fluid is only changed after driving through streams high enough water might get in, not based on mileage, since mostly drive in 2WD mode. I don’t change my power steering fluid unless it gets low enough on the stick to top off, or it looks dirty or smells burned then I change it. Usual reason PS fluid gets changed, something happens which requires I remove the pump.

Changing rear diff fluid every 30K miles probably a good idea, but seems a little excessive, esp if truck is gently driven. I’d defer that to 45 K myself. As long as it hasn’t been submerged, I change my truck’s every 50 K or so. Same w/xfer case. In my truck’s config, xfer case doesn’t do much in 2WD mode, just passes rotation from front to rear directly, no gears involved, so fluid change unlikely to be of much preventative maint help.

Auto trans fluid change at 45K seems like a good idea. I do that at 30 K on my truck. I change the coolant every 2, or at most 3 years. Waiting for 5 years is too long imo.

No experience w/your truck. Just my opinion is all.

“the transmission fluid is good for the life of the transmission “……in other words… “ the transmission fluid is good for the life of the warranty “

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When my olds was in the trans shop I asked him about the 100,000 mile fluid. He just laughed. Just a marketing gimmick… I had it changed.

How many days ago was that?

You should go by your owners manual or scheduled maintenance manual that came with the vehicle. You will almost never lose doing that. But, most of those schedules have a time/mile limit and it says “whichever comes first”. For example, your vehicle is a 2016 which could have been built somewhere between July 2015 - June 2016. It would have turned 5 years old in 2020 - 2021.

Your coolant has been in there for 7 years. The manual says 5 years or 150k miles, you are two years overdue. Good thing that GM put a pretty good fudge factor in there but I would not push it much longer. Dexcool is known to gel up if it goes too long. It’s not the leak you have to worry about, it is over heating due to lack of coolant flow. That will blow those head gaskets and warp those aluminum heads.

But you did right by doing some research and asking here and not taking their advice at face value. Now you are better equipped to take care of your vehicle and insure that it has a long life.

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I agree with following the manual but you should not discount the failure modes seen by the dealer mechanics to modify the testing that was done by the engineers and codified in the manual.

I remember an old guy diesel mechanic that related frustration with the dodge diesels that the dealers were having. They took them to thi old guy working in his barn and got them running right. He said to me diesels needed to breath. Something the engineers neglected.

Turbo charger too small?

I suspect he was changing the injector timing, a common method of power improvement on the early Commings diesel engine. The 1989-90 Cummings engine was rated at 160 horsepower.

Dealers can face fines for making modifications that affect tail pipe emissions but the guy in the barn is regarded as the smartest man in Minnesota.