No Transmission Service or Tune up

[Ruikee]

2015 LT 4WD
I bought this vehicle in 2017, ex rental, had about 60k miles if i recall. I am coming up on 200k miles. Since i have had it, i have done nothing but change the engine oil, tires, and brakes. Just did shocks and struts about 10k miles ago. I havent had any issues, gas mileage is still pretty normal.
Occasionally the tranny upshifts for a second then back. Checked the fluid, still good, doesnt smell burnt or anything. Took it to a trans shop. He asked if i have serviced it ever, and I said not since ive owned it. He said not to touch it or problems will start up due to the detergents in the new fluids, almost certain it would cause problems.
Thoughts?
And as far as a tune up? Should i do anything about that, and what should be replaced?
Again, no issues TBH

 

[swathdiver]

2015 LT 4WD
I bought this vehicle in 2017, ex rental, had about 60k miles if i recall. I am coming up on 200k miles. Since i have had it, i have done nothing but change the engine oil, tires, and brakes. Just did shocks and struts about 10k miles ago. I havent had any issues, gas mileage is still pretty normal.
Occasionally the tranny upshifts for a second then back. Checked the fluid, still good, doesnt smell burnt or anything. Took it to a trans shop. He asked if i have serviced it ever, and I said not since ive owned it. He said not to touch it or problems will start up due to the detergents in the new fluids, almost certain it would cause problems.
Thoughts?
And as far as a tune up? Should i do anything about that, and what should be replaced?
Again, no issues TBH

These aren't Turbo 350s, change the fluid. Just change out half with the filter. You've been fortunate, the transmission thermostat causes them to fail in about the half the time. If interested in lowering its temperature, look up "flip the pill" here and other forums, easy peasy. GM also makes a lower temperature thermostat now as well.

Tune up consists of plugs and wires. Time for an air filter?

 

[Bill 1960]

Replace the plugs and plug wires. These will run with incredibly bad plug gaps, but you won’t notice any degradation in economy or performance because it’s so gradual, until it reaches total failure- then you get a miss.

I would change the trans fluid. I wouldn’t flush it, or put any foreign chemicals or snake oils in it. Just drop the pan and replace the filter and the amount of fluid lost. I think your risk of continued neglect is higher than the risk of new detergents breaking something loose.

Opinions do vary on this. I can easily see why a mechanic or professional shop doesn’t want to touch it; if it fails they’ll be blamed. OTOH if it fails as-is it’s the owner’s fault and they get to sell a new transmission.

 

[Ruikee]

These aren't Turbo 350s, change the fluid. Just change out half with the filter. You've been fortunate, the transmission thermostat causes them to fail in about the half the time. If interested in lowering its temperature, look up "flip the pill" here and other forums, easy peasy. GM also makes a lower temperature thermostat now as well.

Tune up consists of plugs and wires. Time for an air filter?

Thanks, i did forget after posting that, yes i have changed the air filter a few times. I might add, i also tow my boat a lot and sometimes long distances. Any recommendations on plugs and wires? I also did change the internal cab filter once as well.

 

[Ruikee]

Replace the plugs and plug wires. These will run with incredibly bad plug gaps, but you won’t notice any degradation in economy or performance because it’s so gradual, until it reaches total failure- then you get a miss.

I would change the trans fluid. I wouldn’t flush it, or put any foreign chemicals or snake oils in it. Just drop the pan and replace the filter and the amount of fluid lost. I think your risk of continued neglect is higher than the risk of new detergents breaking something loose.

Opinions do vary on this. I can easily see why a mechanic or professional shop doesn’t want to touch it; if it fails they’ll be blamed. OTOH if it fails as-is it’s the owner’s fault and they get to sell a new transmission.

Thanks, any recommendations on plugs and wires? any recommendations on what type fluid to use at this point? I also tow my boat, sometimes long distances as well.
That does make sense about the pro shop not wanting to touch it...

 

[Miami-Dade]

2015 LT 4WD
Occasionally the tranny upshifts for a second then back. Checked the fluid, still good, doesnt smell burnt or anything. Took it to a trans shop. He asked if i have serviced it ever, and I said not since ive owned it. He said not to touch it or problems will start up due to the detergents in the new fluids, almost certain it would cause problems.
Thoughts?
And as far as a tune up? Should i do anything about that, and what should be replaced?
Again, no issues TBH

When it comes to changing out the the tranny fluid I only let the dealer do it. Not a trans shop. The dealer would also have to have a 5 star review or close to it with mostly positive reviews.

I stopped doing tune ups years ago. I do change out filters when needed.

My 2016 goes in for regular service every 5K miles.

But that is just me. To each their own.

 

[swathdiver]

Thanks, i did forget after posting that, yes i have changed the air filter a few times. I might add, i also tow my boat a lot and sometimes long distances. Any recommendations on plugs and wires? I also did change the internal cab filter once as well.

OE plugs and wires for me. Get your VIN out and plug it in here:

https://parts-catalog.acdelco.com/acesCat.php?

Run the severe service schedule from now on, not double the "I don't drive it anywhere" schedule! LOL

 

[OR VietVet]

What has been said already. IMO, do the Genuine GM plugs and wires, clean the MAF and MAP with correct fluid from parts store, change the trans fluid in the pan and the filter and maybe do again after 15k miles to try and get some more fresh fluid in there and I would not worry about the detergents recommendation from that shop. How do the belts look? How do the hoses look? Time to flush coolant and brake fluid and change fluid in diff's and transfer case and power steering fluid.

Or drive it till it drops or leaves you stranded because it likely will one of these days. "Maintenance pays and breakdowns cost".

 

[Doubeleive]

on the flip side of that coin it's probably going to be cheaper to fix the transmission now rather than later
I would just have them go thru it and replace what is worn, do the common fixes and upgrade the torque converter as that is the weak spot and you are well into the mileage where it happens, it's going to suck when you have to have it towed and have the boat find a way home as well.

 

[drakon543]

im going to side with the trans shop that said not to touch the trans. regardless to the type of automatic transmission its still operated by servos and pistons and whatever else that need to be sealed properly for proper operation. if the fluid isnt changed regularly the natural buildup of an automatic transmission starts and becomes whats actually sealing the transmission actuators and such. the fresh fluid will clean that out of where its been sitting due to the fresh detergents and the sudden change in fluid pressure from fresh fluid. changing the fluid on a transmission like yours that is still working but is long past its service date is going to give you at best a 50/50 of making it better or killing it