2012 Suburban LTZ 4wd Inspection - Have questions

[cmatt]

So I brought this vehicle home last week and I’m looking things over throughout. I wanted to get some input on a few things I found.

First, a little history. It’s a 3/3012 build and spent the first 8 months of its life as a GM corp vehicle in Michigan. Then the rest was spent in Texas in the DFW area.

It’s just shy of 135k miles now. There’s a pretty thick layer of dust/dirt throughout the engine and chassis area underneath. The TB looks pretty dirty and the air box top won’t completely seal as the screws are either stripped or the plastic broken.

When I pulled the spare (also caked in dirt) I noticed the heat shield was broken.

The battery appears to have been recently replaced, but they didn’t reinstall the hold down block/bolt.

I also noticed the aux trans and oil cooler lines have a leak which I believe is not uncommon.

The shocks appear to be the originals. I didn’t see any signs of leakage, the compressor cycles on and the rear shocks hold air.

Fronts

Rear

Sent from my iPhone using Tapatalk

 

[91RS]

Don’t see anything really out of the ordinary for a used vehicle? All easy stuff to fix. If that’s all that’s wrong with it you’re doing great.

 

[cmatt]

I do have some concerns about the rack and need to know if they’re valid. There appears to be a leak at the bottom and perhaps inside the driver boot. The fluid doesn’t look too brown. Steering requires some effort. Keep in mind I’m coming from a K2XX with the electric assist steering where you could turn lock to lock with one finger while parked.

There doesn’t seem to be any grease in the ball joints and everything looks original (steel CAs).

Sent from my iPhone using Tapatalk

 

[cmatt]

Also, I noticed the rear bumper didn’t look right. Found zip ties holding the guide tube to the spare tire winch. It was loose. Luckily it was easy to correct.

Sent from my iPhone using Tapatalk

 

[cmatt]

@swathdiver or whoever else would know, remind me what these two bundled wires are.

One is between the under hood fuse block and fender.

The other is on the main chassis harness loom under the brake booster.

Sent from my iPhone using Tapatalk

 

[91RS]

These are definitely different feeling than electric power steering. That gear might be starting to leak but I wouldn’t worry about it until it is actually dripping fluid.

Ball joint boots look normal. These don’t have grease fittings and require no maintenance. You can squeeze the lowers with a pair of pliers to see if there is play in them. To check the uppers you need to push on the top of the tire whole pulling on the bottom. If you have movement going both directions you could have a loose wheel bearing as well.

 

[91RS]

Trailer wiring.

 

[swathdiver]

The wire bundle under the brake booster is the hot wire to the trailer, if you wanted to charge the battery or run interior lights, fridge, etc. This goes on one of the two posts in front of fuse box, only fits one of them. The other between the fender and fuse box is for an Aftermarket Trailer Brake Controller. Goes to the other stud.

No rust, just Texas dust. New airboxes are not expensive and used ones can be had for next to nothing on the social platforms.

Trans line is sweating, not weeping or leaking; plenty of time on it still.

 

[Doubeleive]

all looks pretty normal to me I have a 2012 also around the same mileage, the power steering looks like maybe it is just sweating a smidge, maybe clean that up and then keep an eye on it.
if you plan on keeping it for a while I would flush all fluids, brakes, power steering, differentials, transfer case, transmission, coolant. and other stuff like plugs/wires. that battery hold down is about $10.00 for the holder and the bolt on ebay. you could maybe get away with having that heatshield welded back together.

 

[cmatt]

all looks pretty normal to me I have a 2012 also around the same mileage, the power steering looks like maybe it is just sweating a smidge, maybe clean that up and then keep an eye on it.
if you plan on keeping it for a while I would flush all fluids, brakes, power steering, differentials, transfer case, transmission, coolant. and other stuff like plugs/wires. that battery hold down is about $10.00 for the holder and the bolt on ebay. you could maybe get away with having that heatshield welded back together.

So here’s the $64,000 question. What do you like for brake and differential fluids? Any issues with putting 75W90 synthetic in both diffs?


Sent from my iPhone using Tapatalk

 

[cmatt]

BTW why do some GMT900 SUVs have steel CAs and some have aluminum?


Sent from my iPhone using Tapatalk

 

[Doubeleive]

So here’s the $64,000 question. What do you like for brake and differential fluids? Any issues with putting 75W90 synthetic in both diffs?


Sent from my iPhone using Tapatalk

I usually just get whatever the dealer sells me, I bought power steering fluid off amazon (oem) but I think I saw the same stuff cheaper at the auto parts store.

 

[gooffeyguy]

That pic of the underside where the spare tire goes, is all that light brown color dust?

Sent from my SM-G930V using Tapatalk

 

[cmatt]

That pic of the underside where the spare tire goes, is all that light brown color dust?

Sent from my SM-G930V using Tapatalk

Yes. It’s coated the waxy GM frame pretty well. Hopefully next weekend I’ll have some time to put it up on ramps, get on the creeper and use the pressure washer (at a low psi).

First, I’ve got to get these K2XX suv harness orders out the door. Been crazy busy at my day job and time has been at a premium.


Sent from my iPad using Tapatalk

 

[swathdiver]

BTW why do some GMT900 SUVs have steel CAs and some have aluminum?

Weight and balance (fore and aft weight distribution).

"Thought" I had it all figured out and the more I learned, the less I knew! All I know for sure is that the XFEs got them as part of their weight reduction plan.

 

[avalonandl]

Broken heat shield is very typical. Mine is broken....

 

[cmatt]

Broken heat shield is very typical. Mine is broken....

Interesting. Any idea what causes it to break? I wouldn’t think anything from the chassis would come in contact with it.


Sent from my iPhone using Tapatalk

 

[avalonandl]

Vibration, fatigue....

 

[mike singleton]

Use GM OEM Specifiic fluids for both diffs and synthetic for brake fluid.

 

[cmatt]

Discovered the rear HVAC/radio control module wouldn’t work. The buttons illuminate, but no display or function. I can turn on the rear air via the front control.

Pulled the back console panel off to investigate and it looks like a soft drink was spilled. The buttons depress and release very slowly. Prob gummed up with the left over syrup.

I guess I’m buying one. Do they have to be programmed?

I may have to look into picking up a Tech2.


Sent from my iPhone using Tapatalk