How would you test drive a 2015 Yukon with 102k?

[swathdiver]

Hi all, 20+ year Ford owner here, hopefully making the switch to GM tomorrow.

I'm test driving a 2015 Yukon SLE with the 6 speed transmission and 5.3 engine.

After looking around the forums, I'll be checking the 4WD selector first, to make sure it's on 2wd and not on A4D.

I plan on replacing all fluids and filters, tuning it up, etc. to make sure it's safe for towing our 3000lb camper.

I'm a single dad that hasn't had a car loan since 1998 and have gotten 4 vehicles to over 250k miles. I mention this because I'm willing to spend money and garage time to keep my vehicles running right, and am proficient enough for most repairs.

If you were test driving this Yukon, what would you check for? Any driving maneuvers or undercarriage spots you would check?

Those early years had trouble with buffeting at speed, there was not enough glue in the roof bows. Should be fixed by now if it was an issue with yours. You FORD guys are always mechanically inclined, have to be! LOL Just funnin' ya! I miss my '96 F-150 sometimes!

What exactly changed with the torque converters for the 15+ versus the 6L-80E in my NNBS Tahoe? Is the AFM in the 15+ just as dangerous as in the NNBS'? I know GM made some changes through the years (valve cover internal PCV deflector, etc). I actually used HPTuners to disable AFM in my Tahoe the week I acquired it and installed an oil separator kit.

The back plate of the torque converter flexes which breaks away the clutch material and sends it through the transmission. This is usually from overheating and then hot ******* and or heavy towing. The K2s also have a transmission thermostat. This makes them run at engine temperature and more than the converter is their #1 killer. Either "Flip the Pill" or install the new lower temperature unit. Easy peasy.

Blackstone Labs also analyzes transmission fluids. I did mine a couple of years ago and they said it was great. The OE fluid should not go past 45-50K miles no matter how you drive it.

Uhh, apparently R-O-D-D-I-N-G is another banned word. So glad I have no idea in what context perverts might talk that way! LOL

 

[LT1ZOB]

Those early years had trouble with buffeting at speed, there was not enough glue in the roof bows. Should be fixed by now if it was an issue with yours. You FORD guys are always mechanically inclined, have to be! LOL Just funnin' ya! I miss my '96 F-150 sometimes!



The back plate of the torque converter flexes which breaks away the clutch material and sends it through the transmission. This is usually from overheating and then hot ******* and or heavy towing. The K2s also have a transmission thermostat. This makes them run at engine temperature and more than the converter is their #1 killer. Either "Flip the Pill" or install the new lower temperature unit. Easy peasy.

Blackstone Labs also analyzes transmission fluids. I did mine a couple of years ago and they said it was great. The OE fluid should not go past 45-50K miles no matter how you drive it.

Uhh, apparently R-O-D-D-I-N-G is another banned word. So glad I have no idea in what context perverts might talk that way! LOL

Your last comment is hilarious. Thanks, needed a laugh. Anyway, I’ve done the Shift unit (literally a 10 minute job on my buddy’s lift) and I use a Range device to stay in V8 at all times. I bought my truck with 17k miles, have 25k miles now. If I keep it long enough, I’ll report back on whether these devices helped. I will say my trans temp has dropped tremendously since the swap. I see 0 downside to that particular $40 investment.

 

[trailblazer]

Your last comment is hilarious. Thanks, needed a laugh. Anyway, I’ve done the Shift unit (literally a 10 minute job on my buddy’s lift) and I use a Range device to stay in V8 at all times. I bought my truck with 17k miles, have 25k miles now. If I keep it long enough, I’ll report back on whether these devices helped. I will say my trans temp has dropped tremendously since the swap. I see 0 downside to that particular $40 investment.

I installed a Tru-Cool trans cooler in my ‘09 Tahoe that includes a cold weather bypass valve. I’m curious if removing the K2’s thermostatic valve will cause the trans to run TOO cool for those in the North. For the trans to run efficiently it needs to be 170+ degrees F?

Is the shift kit worth it for a 100k mile K2?

 

[LT1ZOB]

I installed a Tru-Cool trans cooler in my ‘09 Tahoe that includes a cold weather bypass valve. I’m curious if removing the K2’s thermostatic valve will cause the trans to run TOO cool for those in the North. For the trans to run efficiently it needs to be 170+ degrees F?

Is the shift kit worth it for a 100k mile K2?

My buddy did the Shift on his Silverado about 6 months ago, then replaced the TC at 122k miles. Not sure, but I think the damage was already done. I too worry about the cold weather. I run the truck 15 minutes in morning before I drive, but it was -9 last night. I no longer get into the 170s unless I’m idling a while in traffic. 130-140 is the norm after I installed the kit

 

[trailblazer]

I think the new replacement OE valve part number is 86774933. Has a full-open temperature of 158F versus 194F.

 

[nick14226]

You may have already made your decision, but if still looking at a 15-17 I’d check to see if this was done. If not try to work it into the deal preemptively.

https://static.nhtsa.gov/odi/tsbs/2018/MC-10145171-9999.pdf

 

[trailblazer]

Picked mine up yesterday for $29k (92.5k miles). Thankfully the selling dealer (Jeep/Dodge) also owns a Chevrolet dealership. I asked them to give me a full service history for any dealer work and they emailed me a .pdf of all work performed at any GM dealer. It also included a list of any warranties still in effect. Looks like I'm good until 2025 and 150k miles for the "Special Coverage N182202780" brake booster issue. I'm blown away how fast they had to replace a headlight and taillight unit at 1,257 miles when this thing was still warm off the Arlington assembly line! But its had both taillights replaced, the leaking antenna replaced, and the condenser replaced. Hopefully the 3.5 year old condenser was of a better design...

 

[davidbeaver1]

Very nice! Like some else posted, I'm always concerned with where the truck comes from. Get a carfax and see how many owners, where it started its life and if it had any accidents. I never buy vehicles if they come from big cities or salty road areas. The dealers will run a carfax for free for you.

 

[Bigkevschopshop]

I guess the funny thing when I look at all the comments. Anything mechanical is a gamble, some are great, some suck. I think if you can find a vehicle that fits your budget, have a mechanic look it over with you, check the carfax, do as much due diligence as possible, you minimize your risks for sure.

I think how its taken care of is everything on if it will last a load longer than one that was neglected and city driven.

 

[BeenChevy]

Just had my 15 yukon in the shop for transmission service yesterday and everything still looks perfect even at 130k. Biggest issue with the 6l80 in these trucks is the programming that causes valve restriction. These trucks roll of the line setup more for the track than the a daily driver. Either buy a tuner or bring it in for tranny service at your local shop every ~45k for a fluid/filter flush. Have them set the release lower than the apply on gears 1-4 and give a little more torque pressure in between shifts. There are un-named kits that will help longevity as well but even stock is okay if maintained and programmed correctly. The stock programming will eventually cause pre-mature feeder valve to stick and cause the clutches to slip taking out your entire tranny. Doesn't matter a whole lot which torque converter you use so long as it's programmed properly.