Transmission fluid change

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Cam28315

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:(I have a 2017 with 78k miles. Mechanic shop where I do oil changes recommended a trans oil change based on mileage but I know the manual has that listed as maintenance many miles down the road (150k) or so; forget exactly. I’d be worried to change it that long from now but is there any benefit to changing now vs say another 5-10k miles? Worried about something going after changing but want to keep it in top shape as well. Brake fluid and all was changing about 15k miles ago after a brake master cylinder failure:( Searched on the site and read through some threads but didn’t see an answer to something like this so wanted to ask! Thanks!!
 

Trainmaster

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Unless you're doing a lot of towing or severe service, another five thousand miles shouldn't hurt anything. But do you know the history of the truck? Was it overheated or driven in stop and go traffic every summer day? Certainly changing fluid every 60K miles won't hurt anything but your wallet, running around with burnt fluid will shorten the life of your transmission.

If the truck was used in regular service, your 80K or 100K service should be fine. I've always done them around that mileage, and I've never had a failure and kept them all well into 200K miles.
 

Plati

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He said change the oil at 3000 ... It will be all black ... He said.

My oil is not black at 6000 miles when it's changed. A little darker yes but not black by any stretch of the imagination.

2014EL

Even my 2003 ... darker but not all black. I've got a Craftsman lawnmower I never change oil. Now that's black.
 
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johnboneske

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Shops ALWAYS tell you to change it more often, that's how they make their money... Don't waste your money!
 

762mm

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To each their own. Here are my observations from changing fluids in my (new to me) 2014 with 132k miles :


Coolant : Original "gold" coolant looked destroyed. It was turning brown and had gummy/sticky floaties in it. Flushed / replaced with Prestone green OAT coolant.

Power steering : Fluid was dark brown and looked nasty. Replacement fluid (Mercon LV) is bright red.

Brake fluid : Fluid in reservoir looked clean and had a slightly orange tint. If I knew it was in such good condition, I wouldn't have changed it (synthetic DOT 4 type).

Front diff : Fluid was dark gray color and smelled pretty bad. It looked like it was full of microscopic gray particles. It wasn't burnt though, just very dirty with metallic sludge. Fluid changed for 75W90 synthetic and a magnetic fill plug was installed to reduce future contamination (not factory equipped).

Transmission : Fluid / filter did not appear to have ever been changed. Fluid was dark red in color, but in good condition overall. Fluid filter casing was covered in microscopic metal particles and so was the pan magnet (no large chunks, though). It definitely could've used an earlier fluid/filter change to keep all solenoids happy...

Transfer case : Fluid had been changed in it before, as evidenced by the slightly damaged fill plug. Fluid was nice and bright red. I changed it anyway, just to be safe. Magnetic drain and fill plugs will be installed on next fluid change (not factory equipped).

Rear diff : Hard to tell if fluid was changed, as it was in pretty good condition and slightly greenish in color. The rear diff drain and fill plugs are equipped with magnets though, so that might've kept the fluid cleaner than the front diff. Changed it for new 75W140 synthetic.


So, saying that fluid changes "don't do anything but lighten your wallet" is a bit of an ignorant statement, as these electronically-controlled components are very sensitive to contamination... and clearly, most of these fluids were definitely due for a while.
 
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Plati

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To each their own. Here are my observations from changing fluids in my (new to me) 2014 with 132k miles :


Coolant : Original "gold" coolant looked destroyed. It was turning brown and had gummy/sticky floaties in it. Flushed / replaced with Prestone green OAT coolant.

Power steering : Fluid was dark brown and looked nasty. Replacement fluid (Mercon LV) is bright red.

Brake fluid : Fluid in reservoir looked clean and had a slightly orange tint. If I knew it was in such good condition, I wouldn't have changed it (synthetic DOT 4 type).

Front diff : Fluid was dark gray color and smelled pretty bad. It looked like it was full of microscopic gray particles. It wasn't burnt though, just very dirty with metallic sludge. Fluid changed for 75W90 synthetic and a magnetic fill plug was installed to reduce future contamination (not factory equipped).

Transmission : Fluid / filter did not appear to have ever been changed. Fluid was dark red in color, but in good condition overall. Fluid filter casing was covered in microscopic metal particles and so was the pan magnet (no large chunks, though). It definitely could've used an earlier fluid/filter change to keep all solenoids happy...

Transfer case : Fluid had been changed in it before, as evidenced by the slightly damaged fill plug. Fluid was nice and bright red. I changed it anyway, just to be safe. Magnetic drain and fill plugs will be installed on next fluid change (not factory equipped).

Rear diff : Hard to tell if fluid was changed, as it was in pretty good condition and slightly greenish in color. The rear diff drain and fill plugs are equipped with magnets though, so that might've kept the fluid cleaner than the front diff. Changed it for new 75W140 synthetic.


So, saying that fluid changes "don't do anything but lighten your wallet" is a bit of an ignorant statement, as these electronically-controlled components are very sensitive to contamination... and clearly, most of these fluids were definitely due for a while.
Could you elaborate a little more on the sensitivity of the "electronically controlled components" to fluid contamination? I'm not understanding that.
 

jeff kushner

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Yeah 762, you are talking 5 years for those fluids....we should expect degradation....especially in brake, coolant & power steering. The lube oils tend to be harder to break down and last longer but all oils become acidic after bonding to the other molecules of combustion and over the long term this can cause bearing issues but that would likely take 20 years.

Cars today are good, very good but you still need to take care of them.....time does not equal miles......


jeff
 

Plati

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My trusted shop told me brake fluid doesn't degrade. Doesn't need to be replaced. These guy are older running a shop started by their Dad and are very good.

It is hydrophilic ... Can absorb water if exposed to atmosphere.

I'm running original brake fluid in my 2003, except for that bled during maintenance. Works fine. Brakes have performed well
 
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