[Michael Grider]

Ashamed to say my transmission fluid and filter have never been changed, to my knowledge. I'm at about 140K miles and bought my '06, 4cyl, w/ about 44K on it. I've come across some horror stories in doing my how-to and should-I research, including the "I changed my transmission fluid after a gagillion miles and then my tranny gave out." So, I'm interested in the thoughts of those of you with a little more experience: Should I go ahead and do a fluid and filter change, or is there really a risk the transmission will break once I do?

For what it's worth, I'm inclined to go ahead and do it, because going another 140K without changing doesn't exactly sound like a good idea.

M

 

[Brayan Rosales]

Kind of the rule of why you never seafoam old engine, the deposits are keeping it together(saw this first hand)


I would do it, at this point it's going to fail either because you did it, or didn't do it. but it can only get worst if you don't....I think. I'd do it.

 

[cart7881]

I did an initial fluid/filter change on a Trailblazer (same transmission) at 170,000 miles. Vehicle now has 213,000 miles and there have been no transmission problems. When I had the transmission pan removed, I installed a drain plug. Then I drained and refilled the fluid at each of the following five engine oil changes. Probably not necessary, but it made me feel good.

What you would probably not want to do, would be to have the transmission flushed. That could dislodge some particles of sludge that could plug orifices in the valve body.

 

[Browneye]

Definitely change it. It's gonna grenade if you don't - the fluid is highly likely no longer lubricating.

The problem with old trans and fluid is the varnish that builds up that keeps the thing working. When you change the fluid it starts to break that down and sometimes they quit working when that happens. Better to change it than to keep going on old fluid however.

They really should be done ever 25-50K miles depending on use and type of fluid. A full synthetic like Amsoil or Redline is very heat-stable. They are also highly detergent.