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Discussion Starter #1
the trans olm on my 2003 with 72k on it still reads 100% is this right? when should i be looking at changing the trans fluid/oil??
 

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2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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68,458 Posts
Perfectly fine. Let it go past 100,000, especially if you don't tow trailers, race, or do heavy mountain driving on a regular basis.

Transmission fluid is not subjected to the combustion gasses and carbon blowby which contaminates engine oil.

What does your owner's manual say about fluid checks/maintenance intervals ? (See the cautionary text at 50,000 and 100,000 mile intervals)
 

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White Diamond '03 DHS (with DTS floor shift)
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86,783 Posts
It won't change. It will stay at 100 or 99% unless it gets overheated.
I believe in '04 they started to decrement like the engine OLM.
I like to change the fluid at 100K (probably unnecessary)
 

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Devilles: 04 Base,01 base,01 DHS,92 (parents)
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211 Posts
My 2004 Deville base model does change the transmission fluid life percentage downward slowly. whereas my 2001 Deville base model just sits at 100%.
 

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1985 Sedan DeVille
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1,883 Posts
Does your car have an in-line trans filter? I try to change trans oil every few years just to clear it out. The problem isn't the fluid its all the junk that's suspended in the fluid, stuff like clutch material and bearing dust and dirt from the tube and everything else. The only way to get that crap out is to replace the fluid. The longer you delay the more crap is in there. Not like its expensive or anything. If you have an in-line filter you can get by with changing that instead.
 

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1985 Cadillac Seville Elegante
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222 Posts
If she runs well and the fluid doesn't smell south of burnt toast you're fine. My 85 Seville began burning around 137k but that was due to some long hauls and overloading passengers in college.
My mom's 01 DTS on the other hand after the TCC Solenoid job was just fine and fluid was clean despite the solenoid being so bad.
 

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2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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68,458 Posts
Does your car have an in-line trans filter? I try to change trans oil every few years just to clear it out. The problem isn't the fluid its all the junk that's suspended in the fluid, stuff like clutch material and bearing dust and dirt from the tube and everything else. The only way to get that crap out is to replace the fluid. The longer you delay the more crap is in there. Not like its expensive or anything. If you have an in-line filter you can get by with changing that instead.
No inline filters. Primary screens, cleaned on a pan drop. Main filter is accessible at complete overhaul.

The 4T80E is a very clean-running transmission. A simple pan drop and side tank drain (It's a dry sump transmission) removes about 7 to 10 quarts of the 15 total in the transmission/torque converter. The only way to change most of the fluid is to pump the transmission dry using an adapter hose on the fluid cooler radiator port - pump it into a 5 gallon bucket until you get bubbles. Or, have a good Mom&Pop shop use a vacuum exchange machine.

Because it's a dry sump transmission there should be NO fluid on the stick with the engine off. Check level only with the engine idling in P on a level surface. DON'T overfill.

There is absolutely NO reason to change the fluid every few years unless you drag race a lot, tow heavy trailers, or do extensive mountain driving in hot weather.
 
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