Transmission fluid change interval

Isaac Rummell · August 9, 2016

I was wondering what milage people recommended changing the fluid at.my 2011 with 4.8 and 4 speed I assume it's the 4l60e. And I have always heard that you shouldn't really change the fluid in them. I heard that from mechanics and old timers both. As long as the fluid looks good don't change it. Is there any truth to that? The truck currently has 22,000 miles

MS3DALE · August 9, 2016

30,000 miles, its piece of mind for me.

CapitalTruck · August 16, 2016

Those people are way off. Fluid and filter every 30-40k. No flushes...those are a scam. GM recommends fluid and filter change. I sold my last truck with 185k no tranny problems on this schedule. Towed a majorly heavy trailer occasionally.

Colossus · August 16, 2016

Flushes are not a scam. They work GREAT when done properly. Flush every 30,000-40,000 miles.

Z45 · August 16, 2016

Don't listen to anyone who says, don't change the transmission, they don't know what they are talking about. Change the oil every 3,000 miles but ignore the transmission and they call themselves a mechanic?

CapitalTruck · August 17, 2016

Flushes are not a scam. They work GREAT when done properly. Flush every 30,000-40,000 miles.

GM specifically advises against them and to do pan/filter. Not changing filter/cleaning magnets isnt proper maintenance.

Daryl LBZ · August 17, 2016

I'd change the fluid at 30k also.

Z45 · August 17, 2016

There has never been a reason to flush a transmission other than to sell more transmission fluid. A qualified transmission tech can exchange all the ATF without the need for any machine and its just as effective.

Colossus · August 17, 2016

GM specifically advises against them and to do pan/filter. Not changing filter/cleaning magnets isnt proper maintenance.

most have screens, not filters. note I said most. The screens get cleaned via the flush, which is not a power flush so to speak, but rather they use the tranny pump itself to pump in new fluid and a few other things involved in the process that cleans the stuff off the screen. and Yes replacing the filter if equipped is a vital part of the flush process. Lastly- If GM said not to flush the transmissions, then why do they allow dealers to perform these things on GM vehicles? Lots of old wives tales out there about flushing and the potential damage done by doing it.

sdeeter19555 · August 18, 2016

A power flush/exchange machine that simply exchanges fluid is different than one of the machines that adds the solvents before adding fresh fluid. Those are what cause issues...

And the filter in these trucks is a cellulose material, it needs periodically changed. I changed mine at 50k, I exchange fluid every 15k miles...I will next change the filter at 100k.

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Brian Long · August 18, 2016

Coming from a guy that had a dealer destroy a transmission from a flush at 22,500 miles (they flushed it as part of the purchase even though I only requested a fluid change), don't EVER have a transmission flushed. When I say destroyed, I mean stuck on the side of the road with ZERO ability to move. Luckily it was a GM dealer and the truck still had 90 days on the factory warranty, so brand new transmission.

But on your question, I have always gone 20-50k in trucks depending on how hard I have been on the transmission. Heavy towing = sooner.

CapitalTruck · August 18, 2016

From GM technical service bulletin, I don't know how to say it any clearer:

Subsystem Flushing

Flushing of air conditioning (A/C) lines, radiators, transmission coolers, and power steering systems are recognized practices to be performed after catastrophic failures or extreme corrosion when encountered in radiators. For acceptable A/C flushing concerns, refer to the Flushing procedure in Service Information (SI). This practice is not required or recommended for normal service operations.

The use of external transmission fluid exchange or flush machines is not recommended for the automatic or manual transmission. Use of external machines to replace the fluid may affect the operation or durability of the transmission. Transmission fluid should only be replaced by draining and refilling following procedures in Service Information (SI). Refer to Automatic/Manual Transmission Fluid and Filter Replacement.

Isaac Rummell · August 18, 2016

Thanks for info. The mechanics that told me not to change the fluid may have been talkimg about if you had an old truck that never had the fluid changed. My dad always said he never changed the trans fluid or coolant and he never had any problems. But I have always been anal on maintenance.