8 speed fluid and filter change

[tlaw91]

requires the use of the DT-45096 TransFlow Cooler Flush Machine and DT-52263 Transmission Fluid Exchange Tool Kit
 
I am confused?  My service dept. uses this?  Pretty much all the coolant comes out and is brought back into the system via the Trans Pump?  This is a complete replacement.  Cooler is flushed too?  Are you using this system?  Thanks

We drain and fill and replace filter, it’s too expensive to charge for the full 20 quart flush with the Mobil Hp!!

Yeah I know what you’re talking about though


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[mookdoc6]

1 hour ago, tlaw91 said:

We drain and fill.

Yeah I know what you’re talking about though


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I understand multiple ways to skin a cat....Good pictures thanks!

[NWI Denali]

Great pictures and writeup, OP.

[NWI Denali]

OP, are you a GM tech?

[Josh99722]

Hello everyone, if you dont mind i would like to comment.

i have a 2016 silverado 5.3L w/ 8 speed transmission.

i worked at a shop for many years.

using the machine to flush the system can have negative consequences.

if the machine puts too much pressure, you risk damaging a seal.

Also, have seen it where after a flush, debris can be pushed into the wrong part and cause issues.

we always drop the pan, replace the filter then fill it up, remove a cooler line and start the vehicle.

would continue to add fluid while the vehicle would push the old fluid out.

this way there is not too much pressure in the system.

We had seen issues when using a flush machine.

i added a b&m trans pan and added the b&m dip stick tube.

was definitely worth the money!

alot less messy being able to fill it normal.

adding the b&m pan has a drain plug and a additional 3.5 - 4 quarts of fluid.

makes it very convenient to drain quickly and refill w/ the b&m dip stick tube!  

i added a morimoto cooler, and a morimoto radiator.

and finally deleted the transmission thermostat.

reason is i installed a Whipple 2.9L super charger.

my transmission always sat from 180 degrees upto 230 degrees.

 

after the changes, i rarely get over 100 degrees now.

heat is the worst for the clutches.

 

Any questions i would like to help!

[JimCost2014]

10 hours ago, tlaw91 said:

We drain and fill and replace filter, it’s too expensive to charge for the full 20 quart flush with the Mobil Hp!!

Yeah I know what you’re talking about though


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So, not trying to start a S storm (never happens here as long as you use Amsoil), but why do so many GM (all) dealers use the flush system if it is so bad for the transmission? 

 

If it can be directly linked to failures, why would they continue to use this as a service method?

[tlaw91]

Couldn’t tell you what other guys do elsewhere or why. I just know at my dealer we drain and fill 8 speeds and replace filters. 6 speeds it’s fine to flush, but I’d prefer changing the filter out if it was mine. And for what it’s worth I actually fixed an intermittent harsh torque converter engagement on my 2010 Tahoe 6 speed that I just got with 192k on it no history of trans service ever and it’s been great ever since.

But that’s a different 6 speed


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[disneybaker]

You should not do this on the 8 speed transmission.

It has an internal valve that closes the inlet port when the temp isn’t hot enough

So you run the risk of running your transmission dry, trans fluid can leave the outlet all day but if it’s not hot enough the internal valve shuts and won’t let you fill it.

Drain and fill your 8 speeds.


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How about 10sp


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[C Dave]

Thanks to the OP for this write up.   

[Black02Silverado]

On 2/8/2020 at 1:17 AM, JimCost2014 said:

So, not trying to start a S storm (never happens here as long as you use Amsoil), but why do so many GM (all) dealers use the flush system if it is so bad for the transmission? 

 

If it can be directly linked to failures, why would they continue to use this as a service method?

Not sure of other dealerships but the one here that I had and did my 2002 back when I first bought it in 2001.  They hooked up to a fluid tank where the new fluid was in a bladder that got hooked up to the return line from the cooler and the supply line was hooked up to a bladder on top of the new fluid bladder. So as the old fluid flowed in from the transmission on pump to the bladder it put pressure on the new fluid bladder and helped with it to keep flow into the return line back to the transmission.  So the whole process was done by the transmissions own pump and no issues of running dry.  But then my 2002 doesn't have a thermostat on it. 

[txab]

1 hour ago, Black02Silverado said:

Not sure of other dealerships but the one here that I had and did my 2002 back when I first bought it in 2001.  They hooked up to a fluid tank where the new fluid was in a bladder that got hooked up to the return line from the cooler and the supply line was hooked up to a bladder on top of the new fluid bladder. So as the old fluid flowed in from the transmission on pump to the bladder it put pressure on the new fluid bladder and helped with it to keep flow into the return line back to the transmission.  So the whole process was done by the transmissions own pump and no issues of running dry.  But then my 2002 doesn't have a thermostat on it. 

To me this is the definition of an exchange, not a flush and I would think this method would be preferred method. It will cause no harm. 100% fresh fluid!

 

Agreed not going to work on a thermostat controlled trans, but neither would a flush unless bypassing the thermostat

Edited February 11, 2020 by txab

[doropallo]

So I have almost 50K on my 2016 GMC Sierra SLT and since it's a CPO I have a free oil change coming, the brake recall and decided to get the transmission filter and fluid done so I made 2 calls to the local dealers. First dealer tells me $214.99, OK, the 2nd one finally calls back, asks for the VIN and says $467.09. I tell him about the other dealer and he asks if they VINd me. I have an 8 speed and it's significantly more. I then call the other dealer and he verified it's 214.99. I say I have an 8 speed and he says it makes no difference trans service is 214.99. I kept the appointment and will find out on Saturday.

 

I also called the dealership where I purchased the truck and they quoted me $300, so it seems the one is really expensive.

Edited February 14, 2020 by doropallo
Update price.

[Doublebase]

On 2/13/2020 at 3:03 PM, doropallo said:

So I have almost 50K on my 2016 GMC Sierra SLT and since it's a CPO I have a free oil change coming, the brake recall and decided to get the transmission filter and fluid done so I made 2 calls to the local dealers. First dealer tells me $214.99, OK, the 2nd one finally calls back, asks for the VIN and says $467.09. I tell him about the other dealer and he asks if they VINd me. I have an 8 speed and it's significantly more. I then call the other dealer and he verified it's 214.99. I say I have an 8 speed and he says it makes no difference trans service is 214.99. I kept the appointment and will find out on Saturday.

 

I also called the dealership where I purchased the truck and they quoted me $300, so it seems the one is really expensive.

$214.99 sounds like a decent deal...$300, not so much...and $467 is ridiculous. I know some guys that would charge you that for removing the transmission and putting it back in. 

[doropallo]

They did it for 215 plus tax, but I found it amusing when I got there the "Service Advisor" said they would just flush it for 169.  After the guy that actually does the work informed him that it can't be done it needs to be changed he brought me out to inform me and the service tech called him and said that the trans requires a much more expensive fluid, he turned to me and said it's a flat rate no matter what. So it's done for the next 50K.

[Bikemobile]

I got my 8 speed fluid and filter changed for free on this TSB: 

 

Tsb