I recently took my wifes 2000 Nissan Maxima to a transmission specialist to have the tranny fluid flushed. The fluid has never been changed and the car runs fine.

After looking at the fluid and the high miles (120,000) the mechanic suggested not changing it but leaving it as is. He said the fluid had already turned to varnish and that transmission fluid has detergents in it that might make things worse even if he was to just do a drain and fill.

Is he telling me right? What does everyone else say? He didn't charge me anything so it's not like he was trying to take advantage of me.

txgreasemonkey

Personally, I would drop and clean the pan, change the filter, and change all of the fluid, following the procedure below:

http://www.askmehelpdesk.com/cars-tr...tml#post552241

Then, I would add Auto-Rx, drive the car for 1,500 miles, and, following their instructions, likely change the filter and fluid again.

kitch428

I agree with your mechanic. Instead of using the flush machine, do what TX said. Just do drain and fills with the pan cleaned out first.

CaptainRich

If it's working properly now, why are you concerned with it? And why now do you feel you need it flushed?
I don't endorse "snake-oil" treatments instead of maintenance or repair.
Trans fluid is usually one of the most detergent fluids to begin with.
You say he "checked the fluid." He pulled the dipstick? The dipstick frequently appears varnished, but the rest of the system often see's greater fluid flow.
If the flush is done with a higher detergent additive before the entire system fluid is exchanged, all the bad stuff is taken out and fresh clean fluid is installed in it's place.

Interesting point: According to online data, even consulting the Severe Service Interval, A/T fluid has no service interval. That is NO service interval. Inspect only.

If it ain't broke, don't fix it.

Tim M

During routine maintenance (oil changes, 25 point inspections, etc.) over the last year, everybody who looks at the transmission fluid says it's dirty and needs changed. Although we have maintened the oil changes every 3000 miles, we have never changed the transmission fluid since buying the car new. I know it's kind of late in the game to be concerned about the transmission fluid now and I accept the blame, but if it's possible to do anything about it without creating problems then I would like to try to at least change the fluid just once for the remainder of the time that we'll have the car.

The local specialist that we went to is reputable and has been in business for 30 yrs. He's not trying to rip me off but is he telling me the right thing? Is he correct in saying it's too late to mess with it now, and I could cause the transmission to have problems by changing the fluid at this late stage in the game?

CaptainRich

One of the problems I see here is that he's been in business for a long time. That isn't the problem, but he's clinging to old ideas about how vital vehicle fluids were "then" as opposed to fluid engineering as it is now. It's time to dispell the myths.
If you haven't done so already, please read my profile. In addition to decades of automotive experience, there are a number of online venues that will corroborate what I've already stated:

Car Talk

Here's a link from Courtesy Nissan, a dealer in Texas, that has your Owner's Manual:
http://www.courtesyparts.com/nissan-...san-Maxima.pdf
I found nothing that recommend anything other than inspection.
Contact your local Nissan dealer directly and ask for your vehicles normal service schedule.