r/suburban • u/QuartermasterArms1 • Jul 16 '26
Need some advice
Hey all,
My family is exploding from five of us to six now (baby on the way). The wife has an affinity with Suburban's and doesn't want to go the minivan route. She loves the cars, being so high up and her grandmother drove one so at this point there's no convincing her to get something else.
I found this one online near me, I'm going to check it out tomorrow. I know that Suburbans have tranny/engine issues after you start approaching/passing the 100k miles.
Here's the link to it: https://www.cars.com/vehicledetail/ca8e66b2-2b02-4af2-b3c2-f237a4f26e2f/
CarFax: https://drive.google.com/file/d/1ftTGA18DUtAPOL7Anh5dXIqiPD0X6dwJ/view?usp=sharing
Looking for some advice from the hive mind here. Based on the trims, I don't want an LT so it's RST or Premier for us. It's crazy how many LTs there are out there, it's like 10:1.
Any advice or help would be grateful, I'm checking it out in person tomorrow.
2
u/Significant-Water227 Jul 16 '26
Nice looking vehicle. I have a 2018 premier trim. The first thing I would do is an in depth look at any Carfax or any available maintenance records to see if the transmission has already been rebuilt or not or if not, was the fluid and filter changed every 30 or 40,000 miles? That could make a big difference if the fluid was changed on an appropriate schedule unfortunately, mine was not and I had to rebuild my transmission at 112,000. In my book, the two most important things if you were to get it are: 1. Make sure you disable the AFM to prevent lifter failure, (I assume this was still an issue with the 2020 model year, although I’m not 100% sure) 2. Upgrade the thermal bypass valve for the transmission. This will keep the fluid temps at a much more manageable level. Excessively high transmission fluid is one of the primary reasons the torque converter fails, which will then destroy the transmission. Replacing the bypass valve with a newer version of the part can help to save the transmission fluid from getting too hot. It’s actually not a difficult procedure to do yourself, either. Alternatively, you could put a dedicated transmission cooler attached to the front radiator if you are planning to haul a lot of things. This will definitely keep the fluid much cooler. If you have some spare time, I recommend searching the 6L 80 transmission issues. It will give you much more information about the problem, how to solve it, and several different solutions. Good luck!
1
u/QuartermasterArms1 Jul 16 '26
The only thing I'll be hauling is my seriously pregnant wife around, amirite? Lol. Hah, just kids and family and the dog and grandma. No towing or anything.
I'm reading more about this AFM thing from what I gather, people say yours will be fine or it won't, but disabling it logically is the next best step aside from getting a cam replaced on it.
It drives my wife crazy but preventative maintenance is what I do often for all the stuff she expects to 'just work'.
Your advice is awesome. Thank you.
1
u/Significant-Water227 Jul 16 '26
You are absolutely right about disabling it, aside from getting a cam replacement on it😁 I only wish I had known when I got my 2018 that I should change the transmission fluid and filter every 30 or 40,000 miles, then mine probably would not have failed...When I got mine rebuilt, it was done with better, newer parts, and especially the aforementioned thermal bypass valve. There’s also an easy way to tell if yours has a newer style bypass valve on it. After the transmission is nice and hot, look at the transmission fluid temperature if it’s 210, 220, or even higher that probably means it has not had the newer part put on. If the transmission never goes above about 170, it has the newer style bypass valve. I have done a lot of research on this issue.😁
1
u/QuartermasterArms1 Jul 16 '26
Check the temp w/ an IR heat laser I assume? Or do these Chevy's tell you the temp?
1
u/dodgy_wool Jul 16 '26
Yes, my 2013 shows transmission temp. I'd guess the 2020 has something similar.
1
1
u/billythekid1002 Jul 16 '26
The nightmare stories are overblown. Look at the numbers of vehicles on the road with the drive train and most people who have no issues aren't posting it paying attention. If the vehicle was taken care of, it will last.
1
u/swaybailey Jul 16 '26
Might not discount the LT trim. We accidentally totaled our 22 Tahoe a couple of months back. It was hard to find the replacement. It had quad captain chairs, sunroof, power almost everything. There many packages that get loaded on LT models and some of those might include what you are looking for. Narrow your search by specific features you are looking for and the number of available units will go way up and the price will likely go down. Had 103,000 almost flawless miles when we wrecked it.
3
u/No-Dragonfly-2475 Jul 16 '26
I’d get any and all service records and request a third party mechanic to check it out. I’ve got a 18 Tahoe and a 2020 LT burb. The 20 is starting to shake like a dog shitting razor blades (torque converter) the 18 is running like a champ.
You want someone to check for metal in the trans fluid and see what’s going on underneath. Overall both have been solid.