[Tim M]

I recently took my wife's 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:

https://www.askmehelpdesk.com/cars-t...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]

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.

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 dispel 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.

[wolfsong64]

Rather than start another thread I thought I'd jump into this one since the question is similar. I have a 1998 Plymouth Breeze with 190,000 miles on it. I recently discovered that there was an oozing leak that indicated that the trans gasket needed replacement. The issue is that the transmission fluid has not been changed since roughly 1999. Almost to a man I was told that changing the fluid now would disintigrate the bands and cause other problems. I guess I am hoping it isn't true. I'd hate to have to replace the whole darn thing for the cost of a lousy gasket. The trans itself seems to be running fairly decently. I noticed that lately it has taken to shifting a bit hard right around 30 mph. I know she is old and not exactly a classic... but the truth is, I really like this car and want to hang on to it as long as possible.

In talking to a couple of mechanics around here

[TxGreaseMonkey]

wolfsong64, I would drop and clean the pan, replace the filter, install a new pan gasket, and refill with ATF. I've worked on some pretty nasty transmissions for friends and never had a problem. If I wanted to keep the car, I would even consider Auto-RX--check it out online.

[RickMN]

There's plenty of controversy on this subject. Even pro techs cannot agree on the right procedure. Read both sides here Transmission Flush

Personally, I would go with Tx's advice. Dropping the pan, cleaning it and putting in a new filter gets you about 1/3 of total capacity in new fluid. It also gets you a new filter--which is the most important part of the procedure.

I would not have it flushed.

[wolfsong64]

TX & Rick...

Thanks for the advice... guess I know what I'll be doing next weekend. The article was a good one. My first instinct would have been to look for some Lucas oil or something (there is already some in it, I used it to try and help smooth out that rough shift).

I had no idea this would be troublesome. My regular mechanic won't touch it with a ten foot pole and his referral garage wants a second mortgage on my home, one kid, and possobly my mangy old housecat.

Yesterday on the way home from work something started thumping in the rear on the passenger side. I thought it was something going on with the wheel. I dropped into the local tire shop, they put it up, pulled the rears tires off, and found... nothing. Nothing appears to be hanging, loose, broken, rubbing, or in any other way interefering.

My concern is that all of this is somehow linked to the transmission/driveshaft. It only thumps in drive, not in reverse, and the tempo of the thump increases with the speed of the car. Any thoughts on this?

[CaptainRich]

Yesterday on the way home from work something started thumping in the rear on the passenger side. I thought it was something going on with the wheel. I dropped into the local tire shop, they put it up, pulled the rears tires off, and found......nothing. Nothing appears to be hanging, loose, broken, rubbing, or in any other way interefering.

My concern is that all of this is somehow linked to the transmission/driveshaft. It only thumps in drive, not in reverse, and the tempo of the thump increases with the speed of the car. Any thoughts on this?

What speeds are you getting that "thumping" noise? Same speeds in drive as in reverse?

You may have a partially separated belt in that tire. Warm and spinning, you feel it. Sitting still in front of the technician, it looks like a tire. Did they only inspect it, or did they drive the car to duplicate the conditions?

[biggd4355]

If it ain't broke don't fix it! That doesn't work!Change the fluid and filter and be prepared to do it again in the future as maintenance intervals require. To make the task easier ( fluid bath ) put in a b&m plug kit. They are easy to instal and will make the next change a lot easier.

[echo srm 230]

I agree with captian rich if it ant broke don't fix it!!

[Dom1961]

I agree with captian rich if it ant broke don't fix it!!!

It will surely brake a lot sooner by not keeping fluids changed. Transmission fluid takes a nasty beating over time, KEEP IT CHANGED. I do not have an answer for a car with 150,000 miles and whether it should be done. For a couple hundred dollars every couple years your buying yourself great insurance for a vital part of the car. If you care about your ride and want to take care of it keep it changed... Simple...

[patrick7416]

Yes I have a Chevy silver it has 190,000 miles on it my transmission slipping hard do you think if I change the filter and fluids do you think it would help?

[TxGreaseMonkey]

Patrick, probably not--the clutch packs are likely shot.

[andydee]

CaptnRich - Thanks. Today AAA told me I needed a tranny flush - Nissan never mentions it in their 2000 Maxima Owners Manual. Got 140K miles today with no observable issues. Why not leave well enough alone?