Changed my filter and fluid on 8l90 8 speed today

[SuperOldSchool]

Yes, reuse it.

 

[tommyboy180]

You guys reuse the OE gasket or replace?

I replaced but you should be able to reuse it if it's the ribbed version.

 

[richardault]

OP again. Changed again today (fluid and filter) at 130k…. 31k on the fluid. It was still pretty red and not much paste on the magnets.

Also, added the SureCool thermostat to lower trans temps. Good stuff!

View attachment 401349

I was thinking of getting the surecool system, I'm about to do my first transmission fluid change on my 8l90 (2016 Yukon XL denali). Have you noticed a difference since you installed yours?

 

[SuperOldSchool]

I was thinking of getting the surecool system, I'm about to do my first transmission fluid change on my 8l90 (2016 Yukon XL denali). Have you noticed a difference since you installed yours?

It runs about 50-60 degrees cooler than it used to.

 

[irishluder]

I was thinking of getting the surecool system, I'm about to do my first transmission fluid change on my 8l90 (2016 Yukon XL denali). Have you noticed a difference since you installed yours?

I did this a few weeks ago and it runs much cooler, If you are in a cold climate it might be a good idea to warm the vehicle before hammering on it.

 

[SuperOldSchool]

OP again, another refresh at 155k miles - about 25k on fluid.

Just did two extract and refills - 6 quarts each time, then level check. No pan drop with filter change.

I took a quick few minute ride between drain/fill #1 to fully circulate the fluid.

First extract was definitely darker than second.

I plan to do this every 25-30k and hopefully keep the truck running well.

It does shift noticeably smoother after the exchanges.

 

[ss4chad]

GM Automatic Transmission Wiring Harness P/N 24298757 has been Superseded (replaced) by P/N 24046895 according to GM Parts Direct.
I was ordering the harness when I ran across the new P/N and wanted to share that info.

Chad

 

[Joey4g]

I just did my first fluid and filter change on my '16 Denali since getting it. Dealer records show it was done at 56k and I just changed it at 100k exactly and the fluid still had a decent red tint with not much on the magnets.
Only replying because your pictures are a great reference for anyone doing this themselves

Only hiccup I had was trying to get the pan out I gave it a little bump and some little gray what looked like plug cap popped out and I could not for the life of me figure out where it went so I just put the pan back on and filled ‍