Dealer wants $700 to service 4WD system because it was on 4WD Auto when I dropped it off. Thoughts?

Eric Gustafsson · November 15, 2022

Purchased my 2020 Silverado LT Crew Cab 4WD in September, and have put roughly 1800 miles on it. I've never touched the 4WD system, so it's likely been in 4WD auto since I purchased it. I did test it at the dealer, so that's possibly when it has been engaged since.

I dropped it off for an oil change, and the dealer said that I need to have the entire 4WD system serviced because it is not supposed to be in 4WD Auto on dry roads.

How much damage or wear/tear could I have caused in 1800 miles? Do you think the 4WD service is totally necessary? Truck seems to operate totally fine.

Transient · November 15, 2022

Just my opinion, but I don't think the service is necessary. Dealer is correct that it shouldn't be used in dry roads, but my understanding of the system is that it won't be damaged. Excessive use would only increase wear. 1800 miles isn't that much, imo. 4 Auto acts like an AWD system. It won't engage the front wheels until the electronic nannies detect the rear wheels slipping. If they try to push back on a refusal ask them if they try selling the same BS to everybody with a Traverse or Equinox. I think that'll drive the point home to them.

Eric Gustafsson · November 15, 2022

2 minutes ago, Transient said:

Just my opinion, but I don't think the service is necessary. Dealer is correct that it shouldn't be used in dry roads, but my understanding of the system is that it won't be damaged. Excessive use would only increase wear. 1800 miles isn't that much, imo. 4 Auto acts like an AWD system. It won't engage the front wheels until the electronic nannies detect the rear wheels slipping. If they try to push back on a refusal ask them if they try selling the same BS to everybody with a Traverse or Equinox. I think that'll drive the point home to them.

Thanks for the advice, I was leaning the same way. Felt like an idiot for having left it in Auto for so long, but I couldn't really tell any difference in the driving experience.

It's Tim · November 15, 2022

"Excessive wear" would probably be confined to the tires.

diyer2 · November 15, 2022

11 minutes ago, It's Tim said:

"Excessive wear" would probably be confined to the tires.

Agree

Decline for sure.

BIGDOGx · November 15, 2022

It's in auto and no damage should be done to the system, as another reader said the front wheels will not engage unless it detects slipping from the rear.

Did the dealer say exactly what service they want to perform because judging by what your posting imo you should be looking for a new dealership. It won't affect the oil in the trans case or diffs in 1,800 worth of miles driving in auto, so it would be interesting to hear what services they are trying to push on you. I think you should be able to feel ok that nothing bad happened, especially if it is running with no issues at the moment.

fondupot · November 15, 2022

You're fine. This is a trash dealership, I would find a new place to service your vehicle from now on.

JimCost2014 · November 15, 2022

1 hour ago, Eric Gustafsson said:

Purchased my 2020 Silverado LT Crew Cab 4WD in September, and have put roughly 1800 miles on it. I've never touched the 4WD system, so it's likely been in 4WD auto since I purchased it. I did test it at the dealer, so that's possibly when it has been engaged since.

I dropped it off for an oil change, and the dealer said that I need to have the entire 4WD system serviced because it is not supposed to be in 4WD Auto on dry roads.

How much damage or wear/tear could I have caused in 1800 miles? Do you think the 4WD service is totally necessary? Truck seems to operate totally fine.

What are the total miles on the truck? Maybe time to service the system anyway?

Method2Madness · November 15, 2022

100% horse ******. It's fine.

RedLT · November 15, 2022

So what are some scenarios that you would engage Auto 4WD, 4Hi and 4Lo? I've used Auto 4WD and 4Hi on wet/rainy conditions.

redwngr · November 15, 2022

Dealer service adviser is wrong

4Hi shouldn't be used on hard dry surfaces.

4Auto should be OK - but will have slightly reduced fuel economy

2021 LT only has the single speed transfer case - so doesn't have 4Low to consider (is 2020 the same?)

2021 OM says:

The settings are:

2 Hi - (Two-Wheel Drive High) :

Use for driving on most streets and highways. The front axle is not engaged.

This setting provides the best fuel economy.

4 Hi -m (Four-Wheel Drive High) :

Use this setting when extra traction is needed, such as when driving on snowy or icy roads, when off-roading, or when plowing snow.

AUTO (Automatic Four-Wheel Drive)
Use when road surface conditions are variable. When driving in AUTO, the front
axle is engaged, and the vehicle's power is sent to the front and rear wheels automatically based on driving conditions.
This setting provides slightly lower fuel economy than 2 m.

4wd owner/user continuously since 1995 when moved on from 2wd pickups.

I'm not a fan of 4wd Auto (I never use it, but understand why some do) -- but agree with the other responders that, 1800 miles in auto shouldn't be causing it to need extra service.

I guess the only other question is have they done an inspection and found something damaged?

Gangly · November 17, 2022

On 11/15/2022 at 2:49 PM, redwngr said:

Dealer service adviser is wrong

4Hi shouldn't be used on hard dry surfaces.

4Auto should be OK - but will have slightly reduced fuel economy

2021 LT only has the single speed transfer case - so doesn't have 4Low to consider (is 2020 the same?)

2021 OM says:

The settings are:

2 Hi - (Two-Wheel Drive High) :

Use for driving on most streets and highways. The front axle is not engaged.

This setting provides the best fuel economy.

4 Hi -m (Four-Wheel Drive High) :

Use this setting when extra traction is needed, such as when driving on snowy or icy roads, when off-roading, or when plowing snow.

AUTO (Automatic Four-Wheel Drive)
Use when road surface conditions are variable. When driving in AUTO, the front
axle is engaged, and the vehicle's power is sent to the front and rear wheels automatically based on driving conditions.
This setting provides slightly lower fuel economy than 2 m.

4wd owner/user continuously since 1995 when moved on from 2wd pickups.

I'm not a fan of 4wd Auto (I never use it, but understand why some do) -- but agree with the other responders that, 1800 miles in auto shouldn't be causing it to need extra service.

I guess the only other question is have they done an inspection and found something damaged?

Everything above is spot on. I was out of town for a while working any my wife drove the truck in 4 Auto for lord knows how long, on top of the 1000+ miles I put on the truck before I realized she had turned it on a few weeks prior. No issues and no worries. Had it been in 4Hi the entire time, there would have been definite issues, but I doubt the transfer case clutches engaged the front end even once over that period of time.

redwingr: My 2020 LT has 4Hi and 4Lo for what its worth, but it's also a Z71 so you may be referring to LT 4X4 as opposed to LT Z71?

redwngr · November 17, 2022

24 minutes ago, Gangly said:

redwingr: My 2020 LT has 4Hi and 4Lo for what its worth, but it's also a Z71 so you may be referring to LT 4X4 as opposed to LT Z71?

Yes, referring to the single speed box, although the comments about auto vs 4h vs 2h don't change with the 2 speed box.

Pretty unlikely that anybody would run one for long periods on the highway in 4L

Both boxes have autotrac.

Since OP didn't indicate which box and box version doesn't impact the auto/4H/2H discussion -- I chose to ignore it.

Edited November 17, 2022 by redwngr