How often do you change your transmission fluid? I have the 2.4 liter 2LT.

Also, if a car has never had the fluid changed and it has 93K on it, is it a good idea to change it or will it cause problems? I've heard it both ways. The 93K car is my Chevy Lumina.

 

@ 93K, I'd change the tranny fliud. I'm not a fan of doing a flush though.

 

My Pontiac 6000 that when traded in had 297K on the clock. Here's what I did when I was putting on 30k-40k a year. Once a year or there abouts...

Drop trans pan, replace filter, top off
Next service interval
flush trans
repeat

Trans and motor were never opened or required anything else. Ran like a champ in mid 20's mpg. GREAT car!

 

I've heard that changing the fluid can create problems...is this true? Is it only older cars? Or is this just a myth?

 

I had a 2002 Buick Regal before I got the HHR. I think I got a transmission flush at about 90,000 miles, and it has developed transmission problems. It wasn't an overnight thing, but it did start happening after the transmission flush. It now shifts very hard, like it's jerking between gears. I was told that when it starts slipping between gears, or having a hard time upshifting, that's when you have major problems. Right now, it still shifts into every gear and doesn't slip or have any difficulty doing this. They told me that while the hard shifting isn't doing any good, it's not harming the transmission to drive the car every now and then.

 

Ah, well I may be having transmission issues with my Lumina, but I wouldn't want to make it worse by changing the fluid or anything...

 

I've been wondering myself, only 60,000 miles on Paddy, but 100,000 isn't that far off. My experience lies mainly with Powerglides, they need service on a regular basis or they get "grumpy". To be safe I might just do it at 75,000 and go from there.

 

The dealer said I needed to have my transmission flushed at 50k miles. Well, in the manual it doesn't say to unless it's a taxi, which it's not...

 

It's actually easier on the trans to have a firm upshift. Drive a Benz or BMW automatic and they will chirp the tires on each gearshift at full throttle.

The 'smooth' shift is an American preference, and actually is like riding the clutch on a manual trans while shifting. The planetary gearset in an automatic is in constant mesh, so there is no impact on the gears by having a firm shift. The smooth shift actually increases lining wear.

If you ever get the chance, disassemble an automatic trans. There really isn't much in there mechanically.

 

These are filled for life but I would do it around the 125,000 mark I was surprised that my 2010 GMC Seira manual states that it is also filled for life.