Thoughts on changing transmission fluid

[intheburbs]

For the love of all that's holy, please do not even hint at perpetuating the myth "if it's never been changed, don't change it."

If a transmission fails after a fluid change, it was going to fail anyways. But the upside is that you may have extended the life of your trans.

My 6L90 has 200k miles on it, and still functions perfectly. Trans flushes are the only reason my vehicles visit the dealership. I do it every 30k-50k,depending on the duty cycle/how much I'm towing.

 

[79jasper]

When we had our 11 and the trans was going out, had many trans shops tell me the dexron VI loses its color pretty quick. Said cant go off color anymore to judge health.
True or not, no clue. But 3 or 4 shops said that.

Sent from my SM-N960U using Tapatalk

 

[tmt502]

For the love of all that's holy, please do not even hint at perpetuating the myth "if it's never been changed, don't change it."

If a transmission fails after a fluid change, it was going to fail anyways. But the upside is that you may have extended the life of your trans.

My 6L90 has 200k miles on it, and still functions perfectly. Trans flushes are the only reason my vehicles visit the dealership. I do it every 30k-50k,depending on the duty cycle/how much I'm towing.

thank you for that input. That's exactly why I'm here. I want some salt of the earth, reality based input from people who geek out on these trucks.

I asked the shop for the quote just to get an idea of what that cost would be if something does fail after I change the fluid. Just covering my bases for a worst case scenario I guess. Call it risk management if nothing else.

 

[Fless]

thank you for that input. That's exactly why I'm here. I want some salt of the earth, reality based input from people who geek out on these trucks.

I asked the shop for the quote just to get an idea of what that cost would be if something does fail after I change the fluid. Just covering my bases for a worst case scenario I guess. Call it risk management if nothing else.

Seems like an OK plan, just to know. Change the fluid as @intheburbs said, and move on.

 

[89Suburban]

What if someone like me I got over 320K and have no idea of the service life or if it is even the original, but feels fine? I've owned it going on 3 years, maybe put 32K on it since then. Fluid looks okay to me, red and clean? Scared to death to mess with it an kill it from all the urban myths.

 

[donjetman]

Send a sample to a lab for analysis.
JG Lubricant Services
Oil Analyzers Inc
Blackstone Labs

 

[cfmistry]

What if someone like me I got over 320K and have no idea of the service life or if it is even the original, but feels fine? I've owned it going on 3 years, maybe put 32K on it since then. Fluid looks okay to me, red and clean? Scared to death to mess with it an kill it from all the urban myths.

I'll be very impressed if that's the original trans. Most don't make it past 200-250k.

 

[thompsoj22]

Im guessing you have the 6spd and congrats on the new to you vehicle. Drop the pan and take a look, perform a "biopsy" of your trans health. If there isnt a bunch of debris than than you can relax a bit knowing you have done the right thing and "filter/full flush" of the trans. If there is "excessive" debris such as any metal flake or chunks of anything than throw a filter at it and replace the fluid in the pan only with no flush and start looking for a trans/radiator/cooler. I would also advise pricing a GM authorized reman trans and have it installed by the dealer. See if the price difference is worth the 3yr/36,000 mile warranty that includes repair/towing to any dealership in the US. If you are going to tow/travel this is worth alot of peace of mind.

 

[intheburbs]

What if someone like me I got over 320K and have no idea of the service life or if it is even the original, but feels fine? I've owned it going on 3 years, maybe put 32K on it since then. Fluid looks okay to me, red and clean? Scared to death to mess with it an kill it from all the urban myths.

Red, clean and smelling detergenty is a sign of new/healthy fluid. No way, no how that's the original fluid if you have 320k miles. Previous owner(s) must have serviced it.

I will say that next time you change the fluid, upgrade to Dex6. No downside. It's light-years better than Dex3.

 

[Meccanoble]

The transmission drain/refill process is super safe. Unlike a flush that may remove fluid from the transmission itself, the drain/refill only removing the extra fluid in the pan. Letting good fluid circulate into the tranny is the best thing you can do for the tranny. If it fails after that, it literally is on its last leg and will fail soon anyway. If you were taking fluid directly out tranny that needed the dirt to maintain, thats a different story but drain and refill is only removing the extra.