Let’s Play “Is it motor oil or ATF?”

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Doctor Diesel

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Answer: ATF

This is out of the 4L80 in the K2500 Farm Truck with a new life. This fluid had a life of dirt and heavy pulling. Before I changed it out I sent an oil sample to CAT and let’s say it wasn’t good. The only thing going for it was “normal” amounts of friction material so I know the clutches are TOO worn. Lots of water, pretty dirty, viscosity almost didn’t exist.

Before I changed the fluid, I dumped a container of Sea Foam Hydraulic Cleaner into it and ran it for well over 500 miles. Before changing the fluid, the transmission had harsh shifting, converter shudder and was sapping engine power. After the cleaner had time to work fluid change started.

I disconnected the external cooler return hose and hooked it to a suction unit and got about 1.5 gallons out before it sputtered. Reconnected the hose, started the truck and shifted through the gears. Trans still shifted. Repeated the process until the trans wouldn’t shift and I couldn’t pull fluid out. I then directed the suction hose to the bucket and started the truck. I added new ATF and out came another two quarts of nasty. I added fresh fluid until that was what was being dumped out. Reconnected it all and filled with that sexy Mobil 1 you see. This is the latest and greatest and is the type specifically engineered by Mobil for GM to rectify those Colorado trans issues.

Test drive and WOW! That trans shifts like it’s new from the factory. No harshness putting it in gear, shifts are smooth as silk and I gained 1-2 MPG in fuel efficiency. Trans also runs about 5-7 degrees cooler. Converter shudder is still there (What do you expect at 25 years and almost 180,000) but it has gone down considerably. I did not change the filter due to the line pressures being damn near factory after the change. I assumed they would get there with the new fluid. The trans is scheduled for a rebuild next year but this seriously needed to be done regardless. The truck well pulls it max capacity and sometimes then some and in the South it’s easy to cook a trans. For 45 minutes of work, teaching the apprentice how to do it without a fancy machine and the improved trans performance, it was worth the $145 in fluid.
 

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AuroraGirl

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Answer: ATF

This is out of the 4L80 in the K2500 Farm Truck with a new life. This fluid had a life of dirt and heavy pulling. Before I changed it out I sent an oil sample to CAT and let’s say it wasn’t good. The only thing going for it was “normal” amounts of friction material so I know the clutches are TOO worn. Lots of water, pretty dirty, viscosity almost didn’t exist.

Before I changed the fluid, I dumped a container of Sea Foam Hydraulic Cleaner into it and ran it for well over 500 miles. Before changing the fluid, the transmission had harsh shifting, converter shudder and was sapping engine power. After the cleaner had time to work fluid change started.

I disconnected the external cooler return hose and hooked it to a suction unit and got about 1.5 gallons out before it sputtered. Reconnected the hose, started the truck and shifted through the gears. Trans still shifted. Repeated the process until the trans wouldn’t shift and I couldn’t pull fluid out. I then directed the suction hose to the bucket and started the truck. I added new ATF and out came another two quarts of nasty. I added fresh fluid until that was what was being dumped out. Reconnected it all and filled with that sexy Mobil 1 you see. This is the latest and greatest and is the type specifically engineered by Mobil for GM to rectify those Colorado trans issues.

Test drive and WOW! That trans shifts like it’s new from the factory. No harshness putting it in gear, shifts are smooth as silk and I gained 1-2 MPG in fuel efficiency. Trans also runs about 5-7 degrees cooler. Converter shudder is still there (What do you expect at 25 years and almost 180,000) but it has gone down considerably. I did not change the filter due to the line pressures being damn near factory after the change. I assumed they would get there with the new fluid. The trans is scheduled for a rebuild next year but this seriously needed to be done regardless. The truck well pulls it max capacity and sometimes then some and in the South it’s easy to cook a trans. For 45 minutes of work, teaching the apprentice how to do it without a fancy machine and the improved trans performance, it was worth the $145 in fluid.
uh I am not familiar with Syngthetic LOW VISCOSITY ATF High Performance but you DO NOT want to use LV fluid in a 4l80e. youll burn up what you have left. Mercon LV and Dexron (LV???) are for different breed of transmissions.

also, your method of flushing is harsh to say the least on a transmission.
Also your picture of the fluid is just a reflection of the sky. if you had water you have to bypass your radiator unless you replaced your radiator already
 

AuroraGirl

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Dexron VI is most similar to Mercon V. Mercon LV in a Mercon V application would likely ruin it in short time
Its annoying because the aftermarket slaps Dex/Merc on everything thats nonsynthetic pre DEx vi/merc v , they slap "Synthetic Multipurpose" on generic Dex VI/Merc V, but not using the names, then they also sell "Dexron VI" and "Mercon V" fluids and then ALSO there are the LVs and the other special named new comers that just add to the mix.
 

AuroraGirl

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Meets Dex VI specs? Fine ,but Dex III has been relabled for manual transmissions only.
and transfer cases. and that isnt even all of them, they primarily have that for seal compatibility. still sold new (Thats the only package to buy dexron III in) but there is Dexron Gold label or something that is the ideal use-for-dex-ii-and-older applications
 
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Answer: ATF

This is out of the 4L80 in the K2500 Farm Truck with a new life. This fluid had a life of dirt and heavy pulling. Before I changed it out I sent an oil sample to CAT and let’s say it wasn’t good. The only thing going for it was “normal” amounts of friction material so I know the clutches are TOO worn. Lots of water, pretty dirty, viscosity almost didn’t exist.

Before I changed the fluid, I dumped a container of Sea Foam Hydraulic Cleaner into it and ran it for well over 500 miles. Before changing the fluid, the transmission had harsh shifting, converter shudder and was sapping engine power. After the cleaner had time to work fluid change started.

I disconnected the external cooler return hose and hooked it to a suction unit and got about 1.5 gallons out before it sputtered. Reconnected the hose, started the truck and shifted through the gears. Trans still shifted. Repeated the process until the trans wouldn’t shift and I couldn’t pull fluid out. I then directed the suction hose to the bucket and started the truck. I added new ATF and out came another two quarts of nasty. I added fresh fluid until that was what was being dumped out. Reconnected it all and filled with that sexy Mobil 1 you see. This is the latest and greatest and is the type specifically engineered by Mobil for GM to rectify those Colorado trans issues.

Test drive and WOW! That trans shifts like it’s new from the factory. No harshness putting it in gear, shifts are smooth as silk and I gained 1-2 MPG in fuel efficiency. Trans also runs about 5-7 degrees cooler. Converter shudder is still there (What do you expect at 25 years and almost 180,000) but it has gone down considerably. I did not change the filter due to the line pressures being damn near factory after the change. I assumed they would get there with the new fluid. The trans is scheduled for a rebuild next year but this seriously needed to be done regardless. The truck well pulls it max capacity and sometimes then some and in the South it’s easy to cook a trans. For 45 minutes of work, teaching the apprentice how to do it without a fancy machine and the improved trans performance, it was worth the $145 in fluid.
Putting synthetic oil in your tranny. The best way to play "who's truck is pissing in my driveway"
 

El Tigre

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Dexron VI is backwards compatible with any/every GM transmission ever made.
Superior to any previous fluid recommended by GM at that time in every way that matters.
 

AuroraGirl

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Dexron VI is backwards compatible with any/every GM transmission ever made.
Superior to any previous fluid recommended by GM at that time in every way that matters.
now i have read the same data as you but I would not put dexron vi in an original condition th350 or powerglide.
after overhaul, maybe, if i know the parts wont leak.

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ACDelco ATF Type III (H) is recommended for the following uses: when DEXRON-III(H), DEXRON-III(G), DEXRON-II(E), DEXRON-II or Type A Fluids are required in all automatic transmissions built by GM that do not require DEXRON-VI and can used in some hydraulic and compressor systems where excellent low-temperature flow ability is required."
 
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