I have a 02 Civic with about 83K miles and I am wondering if it is safe to change the auto transmission fluid? I don't think it has ever been changed. I checked the fluid level and it still good. It's light brown and doesn't smell burnt. The car still runs well. Is doing a drain and fill too risky?
I would say if the trans still shifts and behaves well, go for it. Hondas will do just fine and you will lengthen the life of the trans. I would encourage a drain-and-fill, not a flush.
That being said, If you are noticing the transmission already slipping, or if there is a noticable difference in the shifts, I would say there may be a chance a fluid change would worsen it. The trans in my Ranger started slipping at one point and I thought a fluid change would make it better, but it actually worsened, facilitating a rebuild. The shop showed me the reason, which was a brass O-ring that was flat-spotted by wear on one side. This O-ring is what allowed pressure to build so that the trans would shift gears properly. The new clean fluid actually washed out the dirt and sludge, and made the pressure leak caused by the worn ring worse.
@wse thanks for the advice. I don't notice any slippage yet so I guess I will attempt a drain and fill. I believe it still has the old ATF-Z1 Honda fluid, is it ok to mix with the new DW-1 since Honda no longer makes Z1?
I would check with a Honda dealer... they will likely have a fluid that is backwards-compatible. Hondas are definitely picky... don't buy one of those "compatible with all types" generic transmission fluids from AutoZone. Good luck!
Man that car/fluid is 18 years old!!! I would only do a basic drain/refill.
@porkchophill thanks, will do that this weekend
It is perfectly fine to just drain whatever comes out, drop the pan, change the filter, and refill with the same amount of ATF that drained out (use OEM fluid). This is not harmful as it is not changing out all the fluid in the transmission. The older the transmission gets, the more it relies on the old fluid because it provides some extra friction for the worn out clutch-packs. It is NEVER advisable to do a fluid flush after that much mileage, especially since the fluid and filter have never been changed. It's not even advisable to do a fluid flush on these new modern transmissions. It can damage the internals.
@razmigb thanks for the response. is it really necessary to change the filter? I was thinking of doing just a drain and fill
Yes. It's the same reason why we change the oil filter during an oil change. Might as well change it since you're in there too. A clean filter performs better at catching any dirt such as fine metal shavings and clutch residue. The magnet in the pan is for bigger chunks of metal pieces (if you see any, that's not good). It will prolong the life of the transmission and fluid.
@tpalj01
my owner's manual specifies when the AT filter needs to be changed. Yours might too.
@razmigb wasn't thinking to drop the pan as that is more involved. We just going to drain it from the bolt that I saw on many Youtube videos and refill from the dipstick hole. Dropping the pan seems more than what I might be comfortable doing so I might have to take it to the shop
@tpalj01
it's actually very easy on most vehicles. All you have to do is loosen the bolts and remove the pan. The filter is right behind it and you yank it out. Put in the new filter, a new gasket on the pan and voila! The only challenge is that it's a bit messy and the fluid goes all over the place so you need a large tray to catch it.
Yeah, it's not too hard...just messy. I recommend dropping the pan to take a look at the magnet(s) to see normal or premature wear. You want to see a powdery metal coating on the magnet (normal wear), not chucks of metal bits (damage is occuring). It gives you a good idea on the transmission's health.
@razmigb @mountainmanjoe looked all over the manual and it does not specify when the AT filter needs to be changed. Called Honda to order some ATF and they said it's a nonserviceable mesh filter. Research online seems to suggest that I would not only need to drop the pan but drop the transmission to replace it. That seems like a hell of a lot of work and maybe also too costly to do at a shop 🙁
@tpalj01
You're right, the fluid filter is integrated inside the transmission. In that case, just drain the fluid out and refill with the same amount without dropping the pan. It turns out that the drain bolt on your transmission fluid pan is the magnet itself for catching metal shavings, so you don't need to take the whole pan off to check and clean the magnet. Lucky for you!
@tpalj01
no don't drop the transmission haha. In that case drain & refill is fine.
@razmigb @mountainmanjoe Thanks so much for the recommendations. Just picked up a few bottles of ATF from Honda today and will attempt to do it this weekend.