8 speed fluid and filter change

[rockusaf]

Just wanted to post a quick update since I got back from a ~3000 mile round trip home for the holidays. The truck ran fine, even in the cold NE, first time covered in snow since I got it (not a lot of that down here in Florida), the trans shifted noticeably smoother for now at least. I never really looked at the trans temp much before but it sat around 160-170 while driving down the highway and mileage was about normal at 22-23 mpg for the trip. Overall, I can't complain and have the piece of mind of fresh fluid in the trans at no cost to me.

 

Rock

[3tspapat]

Just did the swap and change on a 2018 Sierra eAssist with 8speed. Note that the exhaust actually runs across the front side of the pan (near the sway bar) and not the rear. Also, the only thing preventing the pan from coming out is the transmission filter. Just wiggle, some muscle and it will come out, or maybe pull out the filter while the pan is still on if there is enough clearance.

 

I pumped out 5 quarts only, but had already filled it back up with 7.4 quarts before checking the waste container. I ended up having a lot of fluid (2.4ish) come back out during the level check. Makes total sense since only 5 quarts came out, but just make sure you check your level after if you didn't measure what you took out. 

 

For those who have eAssist, deeper after market pans made for non-eAssist would likely not fit as the exhaust crosses over at the front of the pan and not the rear. 

 

 

Edited May 26, 2022 by 3tspapat
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[customboss]

On 2/24/2020 at 8:52 PM, jimbrown1 said:

I've never had a leak on a Wix XP filter.  But I do notice lower oil pressure with them than I would expect.  I'm about to try out the EA filters.  

Less restriction is good. 

[customboss]

On 10/14/2020 at 8:18 PM, Black02Silverado said:

If you are using AMSOIL fluids and there is an issue.  Make sure to grab as much of the fluid as possible to be analyzed.  If AMSOIL's fluid caused the problem, which is highly unlikely, they will cover the repair. If the AMSOIL fluid was still in specification and the dealer still states it was the fluid then you contact AMSOIL.  I have talked to other dealers when this was the case and AMSOIL pretty much stepped in and turned it around.  

 

Like stated above.  Here is a copy of AMSOIL's warranty.

I was an Amsoil ( among others) contract  independent  lab and failure analyst for 25 years. My business was independent  not tied to Amsoil or any other entity. 

 

Independent tribological legal expert witness for 30 years. Never was on losing side of a case. 

 

I never saw Amsoil  products cause a problem.

 

I also used oil analysis to garner warrantied repairs of OEM products out of warranty when they blamed other products failure causality. 

 

I have seen Amsoil step in and cover a customer to ease the burden of a difficult situation. 

 

I have seen many OEM's blame lubricants and fuels for their own weaknesses in engineering or execution, or dealer miss steps and throw shade on customer and whatever product they choose to use. 

 

Since GM bankruptcy and reorganization they have indemnified themselves over what they used to cover and so reading fine print a good idea in a serious issue. 

 

A good progressive dealer is a benefit if he or she sees you do good maintenance and care. Finding one you can trust and who wants your business is another story.  Sadly.  

 

Even Magnussen Moss has to be deliberated like any law. But it's there and most dishonest dealers or repair places will back off once engaged if proved wrong. 

 

Retired now for 2+ years but thats my experience with Amsoil products. 

 

 

[Dennis Wigmore]

had the shudder, fluid change and programming didnt make a difference. 

new torque convertor installed - much better. 2017 sierra 5.3 all terrain. 

[TheSJHL]

Can someone please tell me the current GM part number of the correct fluid to use in a 2018 Silverado 1500 with the 8 speed? Thank you.

[pokismoki]

On 6/13/2022 at 11:47 AM, TheSJHL said:

Can someone please tell me the current GM part number of the correct fluid to use in a 2018 Silverado 1500 with the 8 speed? Thank you.

its not the fluid thats the issue

 

its the trans tuning by GM. this causes converter failure.  

Edited September 5, 2022 by pokismoki

[Black02Silverado]

On 6/13/2022 at 2:47 PM, TheSJHL said:

Can someone please tell me the current GM part number of the correct fluid to use in a 2018 Silverado 1500 with the 8 speed? Thank you.

If you are using the GM fluid it is this.   Blue Label” Mobil 1 LV ATF HP fluid (GM part number 19417577).

 

Otherwise a better fluid is AMSOIL's ATL fluid.    

[pokismoki]

8 hours ago, Black02Silverado said:

If you are using the GM fluid it is this.   Blue Label” Mobil 1 LV ATF HP fluid (GM part number 19417577).

 

Otherwise a better fluid is AMSOIL's ATL fluid.    

i bet i could run dextron/merconIII in this trans, with a big cooler w/aux fan, aux spin-on trans filter and corrected tuning and get over 150,000 miles trouble free out of it.

[Likarok]

Opinions please.

 

My 2017 Silverado High Country only has 24000 KM (15000) miles. I have never had any issues with the Transmission problem that 8 speeds tend to have. Since this truck would still have the factory trans fluid in it should I be getting a flush done to ensure that I have the correct Mobile one fluid in it.

 

 

[MikeBMW]

1 hour ago, Likarok said:

Opinions please.

 

My 2017 Silverado High Country only has 24000 KM (15000) miles. I have never had any issues with the Transmission problem that 8 speeds tend to have. Since this truck would still have the factory trans fluid in it should I be getting a flush done to ensure that I have the correct Mobile one fluid in it.

I dunno, I always get my transmission fluid service done every other oil change - oil change twice a year, transmission fluid change once a year.
Still runs great with 90,000 miles and a tune.
Although, I have a 6 speed but I think it would be similar.
As to the fluid type, I just let the dealer put in whatever is recommended.
 

[egxflash]

On 3/23/2023 at 5:23 PM, MikeBMW said:

I dunno, I always get my transmission fluid service done every other oil change - oil change twice a year, transmission fluid change once a year.
Still runs great with 90,000 miles and a tune.
Although, I have a 6 speed but I think it would be similar.
As to the fluid type, I just let the dealer put in whatever is recommended.
 

how much do you pay for the transmission fluid service?

 

I'm getting estimates of $350 in Southern California for my 6 speed.

[MikeBMW]

8 hours ago, egxflash said:

how much do you pay for the transmission fluid service?

 

I'm getting estimates of $350 in Southern California for my 6 speed.

Here is my cost a year and a half ago at the dealer. Time for me to have it done again but I've only put on 8000 miles since the last change, so ...
Also, mine is a a 6 speed so, maybe, a difference?

Edited April 22, 2023 by MikeBMW

[Black02Silverado]

On 3/23/2023 at 6:50 PM, Likarok said:

Opinions please.

 

My 2017 Silverado High Country only has 24000 KM (15000) miles. I have never had any issues with the Transmission problem that 8 speeds tend to have. Since this truck would still have the factory trans fluid in it should I be getting a flush done to ensure that I have the correct Mobile one fluid in it.

 

 

I would wait until 30K and then get it changed.  For as long as it would take you to do it, the cost is nothing.  Not like you are changing it out every  6 months or so.  Fresh fluid on a transmission is never a bad thing and most forget to do it until an issue starts and by then it's to late.

[2018GMC]

My 2018 (Built 12/2017) just turned 21k miles and I haven't had any shuddering issues but decided to attempt at home driveway flush. 

I used the HF transfer pump Multi-Use Transfer Pump (harborfreight.com) to remove most of the fluid from the pan then dropped the pan. I was able to remove the pan without messing with exhaust or removing filter. The original fluid was dark in the pan but hardly any material on the magnets. Shined a light in the filter and it looked like new. I reinstalled the filter (Will prob change when I hit 50kmiles.)

I cleaned pan and I pumped in 7qts of new Mobil 1 Blue label fluid. https://www.amazon.com/Mobil-124715-Synthetic-Quart-Bottles/dp/B07Q3H159N I removed the trans cooler "pill" and inserted the hoses from the HF transfer pump (just the hoses disconnected from pump. But both into jugs and was suprised to see the hose connected to the rear port on trans was pumping clean fluid. I blocked that hose and ran the truck until the front port hose fluid started to look clean. 
Reinstalled pill and trans cooler metal lines.

Checking the level was a pain. Truck needs to be level. I used the offroad 4wd screen on the DIC so it read 0 for truck angle. I let the truck idle until it hit 180 degrees (this is the temp when the pill opens for my max tow optioned truck) I had to add another 1.2 quarts so there was a small stream running out of the 10mm check plug bolt. Reinstalled plug

I have not disconnected battery to perform trans shift relearn since I haven't had any issues. I believe my trans was low from the factory since I ended up using all 12quarts of new fluid and 1.2 quart of the fluid from the flush (it looked clean but would have preferred to use another sealed quart.)

Definitely miss the days of having a dip stick and not sure why both trans cooling line ports on 8L90 transmission were pumping fluid. I've at home flushed many older transmissions like TH350, TH400, 4L60, 4L65 and they all have a push fluid and intake fluid trans cooler line. 

Edited July 17, 2023 by 2018GMC