2016 Tahoe - transmission fluid change?

[HiHoeSilver]

So get this- I’m taking my 2015 Yukon in for trans fluid exchange. It has the 8l90, so no pan drop. They won’t do full fluid exchange (dealer). Just a drain and fill.

I don’t think dealers want to touch these 8l90’s...though 45k is severe fluid interval, tech said dealer won’t do filter changes and fluid exchanges - only drain and fill.

Tech said drain and fill will get 2/3-3/4 of fluid. My truck has 45k on trans ( they replaced with new factory unit at 15k)

I’m going to do it. Clean fluid is better than keeping factory fill for too long.

Thoughts?

I think you're well within the "safe to change" interval. Use the cooler line pump out method, imo.

 

[SuperOldSchool]

I’m sure it’s safe, but dealer won’t do it. They will only do drain and fill . I don’t get how GM has a service schedule and then dealers won’t do it. I get the 8l90 is troubled...

I used online chat with GM to ask what do the GM factory techs say....

They said to do filter and fluid exchange.... they are going to call my dealer and find out why they won’t do it.

Several months ago I was at dealer for something else. Sign in service area had service for full fluid exchange. I asked about it and they said I could wait a bit , but it is a good idea. Now, for my set appt, they will no longer do exchange (not flush, just running full clean fluid using trans internal pump) and just drain and fill. I don’t get it.

Crazy

 

[SuperOldSchool]

Update
Dealer called me after being contacted by GM. They will do pan drop, filter change and fill for about $370. Will take couple hours due to detailed procedure needed - fluid has to be in designated temp range. It’s about 7- 8qts replaced.

Guy from dealer says he’s personally a fan of clean fluid/ regular fluid maintenance but they are being told not to touch the 8l90s... not sure if that’s GM telling them or if that’s their service manager leading the charge.

I plan to do it.

Hope the 10 speeds are better units that the techs and GM actually have faith in....

I’ll report back once it’s done if there’s any new info or drivability changes. I’d love to see the condition of the fluid after 45k...

 

[SuperOldSchool]

I’ll Had it done today. Pan drop, clean pan/ magnet, filter and 7 qts fluid. They used Mobil1 LV HP. Tech gave me couple pics. He says the magnets look spot on from the other 8 speeds he’s serviced . Also said fluid was a little dark, so I think this was a good decision to have it done - 8l90 runs hot, which eats up the fluid. Tech stated that this ‘lifetime/extended trans fill’ idea is not how he treats his personal vehicles either. He too, is **** about the fluids and preventative maintenance. Has been a tech for 25 years, really nice guy and took the time to talk with me about my truck and service.

The 8 speeds (10’s too) require a very specific fluid temperature range to insure trans is not over or under filled, so it’s not really a diy service like days past...especially without having dipstick/ fill tube.

Shifts smoother and does not do the occasional rough 2-1 downshift.

My advice is do it at the Severe Service (45k) interval. Take it for what it’s worth...

 

[HiHoeSilver]

I’ll Had it done today. Pan drop, clean pan/ magnet, filter and 7 qts fluid. They used Mobil1 LV HP. Tech gave me couple pics. He says the magnets look spot on from the other 8 speeds he’s serviced . Also said fluid was a little dark, so I think this was a good decision to have it done - 8l90 runs hot, which eats up the fluid. Tech stated that this ‘lifetime/extended trans fill’ idea is not how he treats his personal vehicles either. He too, is **** about the fluids and preventative maintenance. Has been a tech for 25 years, really nice guy and took the time to talk with me about my truck and service.

The 8 speeds (10’s too) require a very specific fluid temperature range to insure trans is not over or under filled, so it’s not really a diy service like days past...especially without having dipstick/ fill tube.

Shifts smoother and does not do the occasional rough 2-1 downshift.

My advice is do it at the Severe Service (45k) interval. Take it for what it’s worth...



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Good call. Sounds like you got the right tech.

 

[Lt Belspur]

It's really up to how you feel about your vehicle. We spent a lot on these trucks.

Preventive maintenance is worth it in my opinion.