SuperOldSchool

I have the surface rust spots too, with coating cracking off. WTF , can’t GM paint a frame correctly after all their years in the biz. So annoying Wouldn’t mind as much if my 2015 Denali already had not had: new trans at 14k 2 fuel pumps 3 of 4 MRC struts 2 GPS antennae new exhaust system replaced failed lifter new radiator new condensor numerous sensors fan blower motor an injector serpentine tensioner prob more, I can’t remember the whole f’ing stack of repair invoices off top of my head.

Yes, totally understood. That said, any of those syns would be fine for a 5k interval with a quality filter. BITOG has a mind numbing amount of info. I wouldn’t run it 10k necessarily, but 5k works for me.

Changed my transfer case and diffs at 39k - did this myself. Had 8 speed filter changed/ pan drop by dealer with 45k on trans. Next 45k I will do this myself now that I understand how to do it with the 8 speed (YouTube). clean fluids are always the way to go Some pics here. https://www.tahoeyukonforum.com/threads/2015-yukon-change-both-diffs-oil-and-transfer-case-fluid-early-on.94453/

Harvest King 0w20 synthetic with a good filter (K&N, Fram UG, Purolator Boss) every 5k. 5 qts is 14.99, last batch was on Sale 11.99. Can’t beat it. I was using Pennzoil Platinum for a while but found oil pressure drops after like 3k- guessing it thins out. 90k miles. No oil usage yet. Clean oil with a decent filter is key. Not sure brand matters as much as people think.

Tlaw, how difficult is it to disconnect those solenoid clips- its hard to tell from the pic . Is that pick used to spread a plastic clip or depress something? Anyone have input? Would hate to get this far and have issues. thanks!!

Truck is back from dealer. New transmission and new exhaust system ( for the chirping exhaust valve/ baffle issue). I have only driven 20 miles, so way too early to tell if it's 'fixed'. However I notice: No more clunking on launch Reverse engages immediately ( a little hard) without the several second delay 1-2 shift is smooth I realize the ECU or computer needs to adapt and learn my driving, so we will see what a few hundred or a thousand miles brings...

My 2015 Denali is in for trans replacement this week with 15k on the clock. Has same noises and issues mentioned here. I took a tech for a test ride with me and he heard all the noises and clunks. I hope the new factory unit they are installing now has the improved clutch packs mentioned. I wonder If the tech will know when I pick up and ge the summary.... I'll let you all know. SoS