99 suburban trans fluid

[hardheaded]

Getting ready to change the trans fluid in my 4L60E trans and wondering what everyone recommends for the new fluid.
Been running Mobil 1 Dex 3 in it for a long time ,just not many miles on it. Been thinking of running the Dex 6 from the dealer.

 

[mrsilv04]

Since I have 2 - 4L60E's, I'd stay with Dex 3, especially since it is still available. Usually, one doesn't get a choice.
But that's just me. I have zero desire to run Dex 6 in either one.

 

[atikovi]

Synthetic Dex 6 is superior to the old spec D3. Last time I paid like $3.50 a quart when I bought a case of three one gallon jugs from a Chevy dealer.

 

[CKN]

Since I have 2 - 4L60E's, I'd stay with Dex 3, especially since it is still available. Usually, one doesn't get a choice.
But that's just me. I have zero desire to run Dex 6 in either one.

Since it's a superior product to Dex 3 what is your issue?

 

[Furious]

Dexron VI is backwards compatible, if your transmission is healthy and has been maintained then switching to Dexron VI will do no harm especially since you say you don't have many miles on it.

If you were to bring to it to a transmission shop or to a dealer they would put Dexron VI in it.

With that being said you can use any officially licensed Dexron VI that you want it doesn't have to be from the dealer but I actually find that the dealership is very fair on transmission fluid prices compared to parts stores.

I am running O'reilly's Dexron VI (officially licensed) in my Toyota and got more of it to do my Chevy 4L60E.

 

[Furious]

Since I have 2 - 4L60E's, I'd stay with Dex 3, especially since it is still available. Usually, one doesn't get a choice.
But that's just me. I have zero desire to run Dex 6 in either one.

Run what you want but Dexron VI is inarguably superior.

Dexron III will shear down quicker and more compared to Dexron VI, not to mention VI has better oxidation, foam and wear protection which I would prefer especially on a heavier vehicle such as a suburban or a vehicle that is actually worked hard.

GM actually switched the 4L60E's to Dexron VI around 2006.

 

[atikovi]

But my mother in law's second cousin's boyfriend had a 260,000 mile Suburban and he changed the fluid to Dex 6 one time, and 6 months later the transmission blew up.

 

[Furious]

But my mother in law's second cousin's boyfriend had a 260,000 mile Suburban and he changed the fluid to Dex 6 one time, and 6 months later the transmission blew up.

I think the majority of people wait until it is too late and their transmission is already failing so what they do is get the good stuff thinking a fluid change will solve their problems which sometimes it does but in many cases the transmission was worn out/toast so of course it is going to fail within a quick period but fluid change or not it was going to fail anyway.

But why blame yourself for failing to maintain the transmission or failing to realize hey this is a big vehicle with 260,000-300,000 miles it did it's job time for a rebuild when you can blame the new fluid change.

 

[CKN]

I think the majority of people wait until it is too late and their transmission is already failing so what they do is get the good stuff thinking a fluid change will solve their problems which sometimes it does but in many cases the transmission was worn out/toast so of course it is going to fail within a quick period but fluid change or not it was going to fail anyway.

But why blame yourself for failing to maintain the transmission or failing to realize hey this is a big vehicle with 260,000-300,000 miles it did it's job time for a rebuild when you can blame the new fluid change.

I would guess that fluid failure is one of the smallest causes of transmission issues. IMHO.

 

[Furious]

I would guess that fluid failure is one of the smallest causes of transmission issues. IMHO.

Fluid condition plays a big role in transmission longevity as does cooling.

 

[slacktide_bitog]

Dexron VI is the right choice for your Suburban. If your transmission doesn't have a drain plug, get an aftermarket pan that has one. This will make future ATF changes much easier

You don't have to go to the dealer, as there are many aftermarket fluids that are licensed Dexron VI carrying official approval from GM.

Since I have 2 - 4L60E's, I'd stay with Dex 3, especially since it is still available. Usually, one doesn't get a choice.
But that's just me. I have zero desire to run Dex 6 in either one.

This makes no sense. Dexron VI is much better than III, and a full synthetic is even better.

 

[nascarnation]

Since you've been running Mobil 1 Dex 3, which is a PAO based TES-295 spec fluid, there's no need to change based on time, and as far as miles accumulated, you should be easily good to 100,000 miles.