2021 Yukon xl

[Stewmatic]

Hi,

I am picking up my first Yukon XL tomorrow. I am buying it used with 90,000 miles on it. It’s a 2021 with a 5.3L. Before I pull it off the lot tomorrow I wanted to see if anyone had any advice on things to check before I clear the lot and I’m locked in.

 

[jfoj]

2 functional keyfobs, spare tire and jack with accessories. If the vehicle has locking lug nuts the lug nut tool is there and fits propertly or have the locking lugs removed before delivery.

Check the exterior close for rust or damage. inspect the windshield for cracks. Make sure the AC works and look at the tires to make sure they are not mismatched either in brand or size. Verify all the floor mats are there. Typically these trucks do not have a rear cargo mat.

If the battery is original, plan on replacing it soon or see if you can get it replaced before you take delivery. The battery is likely 4+ years old at this point and with all the electronics in these newer vehicles, a weak/bad battery can cause all sorts of strange problems.

Last but not least, check the engine oil level, coolant level and tire pressures. Make sure there are no open recalls as well.

 

[Stewmatic]

2 functional keyfobs, spare tire and jack with accessories. If the vehicle has locking lug nuts the lug nut tool is there and fits propertly or have the locking lugs removed before delivery.

Check the exterior close for rust or damage. inspect the windshield for cracks. Make sure the AC works and look at the tires to make sure they are not mismatched either in brand or size. Verify all the floor mats are there. Typically these trucks do not have a rear cargo mat.

If the battery is original, plan on replacing it soon or see if you can get it replaced before you take delivery. The battery is likely 4+ years old at this point and with all the electronics in these newer vehicles, a weak/bad battery can cause all sorts of strange problems.

Last but not least, check the engine oil level, coolant level and tire pressures. Make sure there are no open recalls as well.

These are all great suggestions, thank you. It’s 38 degrees out here I wonder if I can check the A/C given the climate.

 

[WalleyeMikeIII]

These are all great suggestions, thank you. It’s 38 degrees out here I wonder if I can check the A/C given the climate.

You can if you have them pull it into their facility and hook it up to an A/C machine and verify the high side and low side pressures are in spec.

 

[fondupot]

Check the age of the battery. If it's original, it probably needs to be replaced. We purchased our 2021 in October 2024, around 63,000 miles on it. It had an original AC Delco battery from 2020 in it. And here in the south, batteries do not last much longer than 3-4 years. Truck started and drove fine for the first few weeks we owned it, then I got stranded with a no-start at the grocery store, somehow got it to start but then had a bunch of weird warnings. Spoke to a local mechanic who recommended I change the battery. So I removed it and put a new one in. The old one tested bad. New battery has been great ever since. No issues. Truck drives like an absolute dream.

Here's a video I have on how to replace the battery, for future reference.

There is also a TSB about a rear differential groaning noise on the first few turns after sitting overnight. It can be solved by changing the diff fluid and adding LS additive. But in some cases the limited slip clutches are too far gone and the entire rear diff needs replacing. Luckily ours was solved with just using fresh fluid and LS additive. Many have reported this works and solves their groaning noise too.

Here's a video I have on how to change the rear diff fluid.

 

[Stewmatic]

Thank you, to funny I watched your battery replacement video last night. Another thing I am thinking of doing is changing the Automatic Transmission fluid while it’s still under warranty through the dealer I bought it through.

 

[fondupot]

Thank you, to funny I watched your battery replacement video last night. Another thing I am thinking of doing is changing the Automatic Transmission fluid while it’s still under warranty through the dealer I bought it through.

The first thing I had done on our Yukon 10 spd was the trans fluid. My local shop charges $250 for a pan service. Basically drop the pan, replace the filter, clean the magnets, fill and top off with fresh fluid. I love the 10spd in this truck, it's very smooth and responsive.

This truck had around ~63,000 miles on it when I bought it. I like to do my diffs, trans and transfer case at 50,000 mile intervals.

 

[jfoj]

Lifetime fluid is a BS thing that many manufacturers came up with. The fluid will last exactly the life of the transmission!

If you want your transmission to last, perform a fluid exchange. Since these transmission do not have dipsticks, they are tricky to set the proper fluid level. Be careful who performs a trasnmission service. If there are no leaks a fluid exchange matches the current fluid fill in the transmission, pretty hard to screw up the fluid level performing a fluid exchange.

 

[tagexpcom]

1.5yrs ago I bought a used 2021 Yukon Denali. I took it to a local auto-shop for an inspection because everyone says this is good to do and... I'm glad I did even thought they didn't find anything major it's another set of eyes. They did find a minor oil leak on the transfer shaft coming out the back of the engine.

As an alternative, perhaps go thru a "jiffy lube" for their check list - you might want to change oil anyway.

There are literally ~100 features if you go thru the lists from cameras, air ride? (does is work), to folding mirrors, to folding running-boards, to seat articulation, to AC/Heat (you already mentioned), to Fobs (we only got 1 and had to pay to get a 2nd one as you can't do 'you're own' unless you have at least 2), to lane detection, heads-up display working, 120v plugs in back, towing - can you check the tow wiring?, is there a user's manual in glove box (useful to have one)?, does it have mats (they are expensive to buy), is body dent-free, do doors and hatch and hood open/close smoothly, .....

If you go online, you can likely find a list of features - things like this....


and so on....

Prepare to carve out time (hours, not minutes), get into a feature review mindset, take someone else with you maybe - and methodically go down the list you prepare. Think ahead of time what's OK with you and what isn't.

I presume we're talking 50 or 60K? rather than 5K... so at that level a good seller should be willing to allow the time to go down a list.

And good luck - we LOVE our 2021

 

[petethepug]

Hey, Welcome @Stewmatic ! Nice pull on the truck and saving a ton off your depreciation.

Got the 10L80 10Sp trans, Check!

10L80 + 5.3L for good milage, Check!

Purchase before 100K to make getting a smoking deal on a warranty, Check!

Ally (a GM company) sells service contracts as well as the GMPP from GM also which is an actual warranty.

That coverage means a $2,000k in labor job to fix a $15 rear main seal is $50 or a leaky trans pan gasket will also cover $500 in Trans fluid.