OK so I have mentioned this before; I have an old beater (but so far reliable as can be) 2012 Mazda5 that we bought 10 years ago with 30,000 miles on it.

It’s my daily driver now and I put a good 60+ per day miles on it with my commute which is kinda a long one.

It’s just about at 171,000 miles now and I’m thinking I’ll hit 200,000 right around the time it comes to get rid of it.

Sat down with the wife and went over our finances and looked at the loan on her Odyssey which has a little over 2 more years on it. Neither of us really want to have two car payments at this point.

We decided to get two more solid years out of this car. I’m getting new brakes right now I just put new tires on it but the transmission has been shifting kind of rough at times lately and I was wondering if I should get that changed?

I spoke to the mechanic who was working on my brakes, and mentioned doing a drain and refill and he basically said “absolutely not” just leave it alone. His point was you could pull or stir something up that causes that transmission to fail.

So my 3 options are:

1. Trans flush

2. Trans drain/refill

3. Don’t screw with it and just deal with it

This mechanic I take my car to is a local guy and is extremely honest and never tries to push anything on you. His opinion is very valuable to me. I just didn’t know what the rest of you guys thought, I’m leaning towards just not screwing with it, and just driving it for the next two years.

What do you all think?

Have you ever drained it? I do mine every ~50,000. I've heard the reasoning about "stir something up" before and it never made sense to me. If you were to look inside of a transmission pan and the valve bodies it would make sense. It's spotless in there. Literally zero "gunk"....well, if it has been maintained properly I guess.

Drain/Filter replacement/Refill

quote:

Originally posted by 1967Goat:


Have you ever drained it?

I am 99% certain it is never been touched, we bought it with about 30,000 miles on it which is too early to do anything and have put the remaining 140,000 miles on it and I know I have not done anything with it.

2. Trans drain/refill

You're mechanic is right, if you don't change fluid every 50-60K miles leave it in.

A 'Drain and Refill' plus changing the filter if applicable, isn't gonna 'stir up' anything! It's no different that changing your motor oil in that respect, and you won't even exchange 100% of the fluid by doing so. You will still have existing fluid in the Trans Oil Cooler, as well as within the Transmission that does drain. It will remove some potential contaminants, provide an oil sample for analysis if you're so inclined, and replenish/restore some of the benefits of certain OEM specified additives along with increasing the lubrication properties of the fluid in your transmission. If you feel that the transmission is shifting rough, behaving oddly at times, etc, I would do it. Just be sure to use the exact fluid that Mazda specifies!

Definitely do NOT flush the Transmission though!

I just remember Hondas being advised to never use a powered flush machine & just do a 3x3 (at least for my TL)
Drain/fill 3qts, drive it through all gears, and repeat 3x to effectively circulate all the old fluid out.

Just make sure you break loose the fill bolt first, before draining. Nothing worse than draining the fluid & having no way to refill it.

Does it have a dip stick? If the fluid is still red and doesn't smell bad, I'd say you're fine. Still nothing wrong with a drain/refill and filter change. If the fluid is really dark or stinks, do it 100%.

Your mechanic is wrong. (unless he is talking about using anything other than fresh fluid for the flush, or the pan/lowest part of the transmission is not removable for cleaning, and the filter is higher. And that could be subject for debate).

Dropping the pan, inspecting it's contents, cleaning replacing the filter and adding new fluid and flushing the converter is not difficult and won't "stir anything up".
Flushing the converter consists of refilling, with engine off (to the proper level prescribed for a "refill", then disconnect the return line either from the cooler or at the point it returns to the transmission, then starting the engine and running the return line to a drain bucket while maintaining fluid level and observing the fluid until l fresh fluid flows form the return line into the bucket, shut off the engine, reconnect the line, fire it up and service with fluid until it reaches the "full mark", then test drive several miles stop and go and check/service until on the hot full mark.

It is easier with two people during the flush to monitor/replenish fluid while the other is observing the fluid to the bucket.

What you do not want to do is "flush" with anything other than new transmission fluid, as anything with solvents, will likely damage seals, rings and such.

Nothing wrong with replacing fluid, and that's all the flush is doing, ensuring the converter (about 1/3 or more, the total amount of fluid in a transmission)

And most "seal conditioners" are solvents that soften the seals, to "help" (band aid) transmissions with internal issues (lip seals for pistons, and such), especially if a drain and filter change are not done after the short time the treatment is used. Some people leave it in, and it will destroy seals.

^^^I would call what Sigmonkey's describing as fluid change/exchange, and NOT a flush...It's also an excellent recommendation if you're up for it! It will exchange 100% of the fluid. There's usually a 'procedure' detailed on YouTube, Mazda specific forums, etc that can outline exactly what needs to be done and how (for your specific model/transmission), in order to ensure a complete fluid change. Again, if you believe your transmission is starting to exhibit some shifting oddities, I'd do it!

Here’s what I do. Every 80-90,000 miles I drain the pan and measure how much came out. You can skip measuring if you have a dip stick. Refill and while stationary, shift into each gear including reverse for 5 or so seconds and then back to park. If the fluid I drained is anything but cherry red, then I repeat the above process until the fluid is cherry red.

As I understand it, power flushing can stir up debris in a neglected transmission and that’s a potential problem. Drain and fills don’t do anything more than use the normal transmission processes to replace the fluid. This service greatly improves performance and longevity.

The only time I have had trouble with an automatic transmission is when I had m 2002 Odyssey's flushed at the dealer. They ended up replacing the trans. I will not flush another. Every other oil change I would drain it and add back in the same amount. Kept it pretty fresh. Flushing and stir things up and cause trouble.

Drain and fill.
Also if you are having new hard shift plan you may be a little low.
So I would suggest properly checking the fluid level and not just refilling what is drained.

I do the inline drain/refill that the monkey described, letting the transmission do the the pumping. The flush machines do the same except they have a pump also that helps it all along. The big issue there is the cleaner they pour in. Way too harsh if you are way overdue to change the fluid. A straight up fluid replacement is the only alternative. I'd wait until you have some cash saved for a possible junkyard trans swap, then change that fluid. It will likely be ok and even more likely will help it work better.

You can rig up the same type fluid replacement on power steering systems and I'd recommend doing that too.

Drain/filter replacement/refill with the CORRECT transmission fluid.

DO NOT let a shop or a dealer sell you on a trans flush. I’ve seen waaaay to many transmissions fail shortly after. The last dealership I was at used to push those non OEM flush services with disastrous outcomes many times.

At least one of those companies would offer a so called warranty against transmission failures when “regularly” (their definition) performing their services. Only problem they offered a fixed maximum of around 4K and that’s not enough to fully repair or replace most of todays automatic transmissions.

I've done this on two vehicles and had no problems after about 40-50,000 miles. I drained it after getting it warmed up. Also pumped out the lines to and from the cooler to get as much out as possible.
Replaced the filter and then refilled.

I'm having a hard time with this one. It is true that sometimes a high mileage transmission can fail shortly after a fluid change if it has not been previously serviced. On the other hand, sometimes clean fluid clears up shifting problems, particularly torque converter "shudder."

I don't think this particular transmission has a removable pan or accessible filter, or even a dipstick, for that matter. I don't see the harm in a drain & refill, but it is still a gamble.

ATF degrades over time. Trust me, we make the additives for ATF and formulate the lubricant itself. The R&D for ATF is extensive and expensive. Many tests stress the ATF to understand how it fares over a vehicle lifetime.

However, each OEM has very stringent requirements for the OEM original fill ATF. Read the manual.

A transmission that is not shifting to your standards is indicating a need for maintenance. Changing ATF in a prudent manner, as already described in this thread, is often a good first step. New ATF or a partial replacement will not repair band or plate clutches, magically restore clutch surface porosity, make clutch plates thicker or back to their original designed surface finish. Of course not! But, a new portion of ATF can bring in friction controlling chemistry that may restore acceptable shifting.

If you're worried about introducing a bunch of new fluid in a neglected transmission, do it a little at a time. Pull out two quarts, replace with new, drive for awhile, do it again, etc. Eventually, drop the pan and change the filter. The worst thing to do is to do nothing.