My Infiniti G20 has around 77,000 miles on it and I need to keep it for several more years so I was planning on changing the transmission fluid. However, some people told me that it is bad to do this and to leave it as is. Others say to go ahead. Anyone here have any thoughts or experience on this topic??

conker69,
I have to assume since it's an Infiniti that you're talking ATF here. Usually the replace interval on manual tranny fluid is 30k.
You don't mention if the fluid is dark or has a burned odor to it...
I'd say you have a number of options:
1.Leave it. It'll prolly be fine...unless the fluid is dark or burned smelling.
2.Drain and fill. Unfortunately, with slushboxes, there's no way to get all of the fluid out without flushing it. You can drain what will come out and then fill that same amount through the dipstick hole...
3.Flush and fill...this is what the stealership would recommend and I prolly would to with this many miles, especially if the fluid appears suspect in any way.
The Xterra is my first car with an auto tranny since 1989. I'm not really crazy about it. However, I am planning on doing a drain and fill asap so I can get some newer fluid in there...
Bogatyr

Hey Bogotyr, if I perform step 2 repeatedly, say once every 10k, would I achieve the same results as performing step 3 once 30k or so?

RJ,
Ya, know, I'd like to think so, but you're never going to get all of the old fluid out that way. I figure I'm going to try and do the drain and fill procedure every 30k or so just to get some fresh stuff in there...
Bogatyr

This popular mechanics artical sort of shows how to do a complete flush, don't know how effective it'll be or if it'll work with all cars.

Changing your ATF

There is a pump, similar to a brake bleeder that enables you to 'flush' the ATF out. I was going to go this route but if the ATF looks normal, not dark or burnt, then I may just leave it. I will check this weekend. Thanks for the help.

Why would you opt to just leave it if it looks burnt? I'd think this would only further encourage you to replace all of the fluid ASAP. I know many believe that new trans fluid which has a high detergent content may loosen old sludge and do more damage than good but I am relatively certain I've heard otherwise recently.

I could be wrong, but it seems illogical to run your truck on what you know is worn out fluid yet replace it if it still appears to be somewhat decent. It seems to me that running it on worn out fluid will most definitely shorten the life of the trans so regardless of the consequences of changing fluid I'd think this would be the least desireable option.

Am I overlooking something?

Aren't they saying to leave it if it's NOT burnt? If it's burnt then of course you should replace it.

If the G20 is like any other FWD Nissan, just pull the ATF drainplug and refill(3-5 quarts ATF). You can do this quickly/easily several times a year(every other oil change interval) and will be rewarded with a smooth shifting long lasting transmission.

Don't believe the hearsay. Preventive maintenance is a must for a normal transmission life.

I'm going to attempt the flush and fill tomorrow and will let you all know how it goes. The plan is to change ALL the fluids tomorrow.

if it's burnt you're too late and there is already damage. The key is to replace it before it's too late.