1997 I30 Transmission Maintenance Question

[vonscorpio]

My I30 is a daily driver and my commute is a hellish 1.5 hour a day, average speed 15 mph crawl. I got the car last October with 170,000 miles on it, with unknown maintenance history, but based on a bunch of other factors, it is to be assumed neglected.

Recently turned over 180,000 miles and I have noted an ever-so-slight hesitation when it shifts, specifically under load (i.e. driving up hill, delays dropping out of overdrive, even if I turn off the overdrive manually). The change is so slight I suspect no one else would notice it and may honestly not be an issue. However it's raised the reminder flag that I should probably change the fluid among other maintenance. The fluid is within normal operational levels, and does not smell burnt. It is a pinkish red, like the color of raw steak juice.

Which brings me to my big question: do I take it in and get it flushed? Do I buy a case of fluid and start the "drain and refill every 500 miles" routine? Should I drop the pan and replace the mesh? Do I leave it alone?

I have read on many forums, including Nicoclub, that flushing an old transmission can spell the beginning of the end, but I know ignoring it doesn't accomplish much more.

[NutriaforBreakfast]

i have 243K on my 95 maxima and still have the original transmission
i dropped the pan one time years ago and now I just undo the drain plug to change the trans fluid with my 2 motor oil changes/year
Since you sense neglect on the car you might change the filter and gasket too
If you do drop the pan be sure the pan bolts go back exactly where you took them out as they are different lengths
And don't bend the pan as it might be stubborn to come off at first
Have a clean dump pan and flashlight ready cause you will look for metal in the oil (or whatever else)
Be sure to only put in what you take out-in other words measure what comes out-I usually get 3.5-4 quarts with a drain plug change.
Sounds like the color you describe is ok-if it was the color of a strawberry milkshake there could be water in it
As you noted the smell is important too
The filter is basically mesh screen so it would be tough to clog it up (and unlikely to do so)
It would be nice to know if it was synthetic transmission fluid or regular transmission fluid-no need to change synthetic as often
and it has been said to stick with one or the other
I think people flush as a last resort but you will always get conflicting opinions with your question
Yes you can drain every 500 if you want to and eventually you will have changed all the oil.

[vonscorpio]

Thanks for the reply NutriaforBreakfast, especially the note about different bolt sizes.

I realize the age old question about flushing vs not flushing an old transmission is as controversial as Coke vs Pepsi, but I was hoping someone could statistically back their ruling.

The previous owner kept the inside and outside clean, and I'm guessing oil changes because it is still running smoothly. I'm pretty sure they ran regular fuel in it. After I bought it I replaced all the failing/failed O2 sensors and the knock sensor. It's entirely possible it's the original factory transmission fluid, but I have no clue.
I guess I know what I'm doing next paycheck...

Any recommendation on ATF brands? (and I don't mind paying more if the product is better)
Does anyone know of a way to determine (without records) if it is synthetic automatic transmission fluid? I know you aren't supposed to go from one to the other.

[NutriaforBreakfast]

Since i change mine twice a year i used the generic walmart transmission fluid with a dextron 3 rating

[vonscorpio]

Thanks again. I can't say I'm ambitious enough to change the fluid twice a year... But I will be back with the short and long term effects of servicing an old transmission. Stay tuned...