Is there a difference between the two versions of the Honda Auto Transmission fluid?

[The Stigenator]

I am due for an transmission fluid change, turns out the dealer does not carry the stock fluid ATF Z1 (which is what my 2009 Acura used until now), they have the new ATF DW1 which is the new replacement fluid.

I understand they are compatible but i am wondering if I am switching over, should I just drain one time (50% fluid change) and put in the new stuff, or have to do a 4 time drain and fill to remove over 90% of the original Z1 fluid. My big concern is with transmission fluid life and reliability. I know the original Z1 wasnt very good in hot climates / climbing hills etc, it would wear down faster, I am not sure how the thinner semi-synth DW1 would do in teh same conditions.

For the record my transmission fluid has been replaced ~25-30K miles or so.

 

[bigi]

I am due for an transmission fluid change, turns out the dealer does not carry the stock fluid ATF Z1 (which is what my 2009 Acura used until now), they have the new ATF DW1 which is the new replacement fluid.

I understand they are compatible but i am wondering if I am switching over, should I just drain one time (50% fluid change) and put in the new stuff, or have to do a 4 time drain and fill to remove over 90% of the original Z1 fluid. My big concern is with transmission fluid life and reliability. I know the original Z1 wasnt very good in hot climates / climbing hills etc, it would wear down faster, I am not sure how the thinner semi-synth DW1 would do in teh same conditions.

For the record my transmission fluid has been replaced ~25-30K miles or so.

DW1 is syntethic while Z1 was not. You will find more info here

I've had DW1 for 30K in my Odyssey after fully flushing Z1 out.

 

[JCH13]

If you're swapping over to a new fluid I would suggest a real flush, not just a drain and fill.

I wouldn't second guess what Honda recommends either, they generally have the act together.

 

[thomsbrain]

As you said, the two fluids are compatible so you can drain/fill, or do the repeated drain to have a "flush."

Personally I am going to do a full flush on my Accord because I'm getting ready to tow a trailer through the mountains of Arizona (basically the perfect storm for a Honda transmission).

 

[onza]

I'm using Redline Sythetic Transmission oil, specifically D4 + racing + lightweight mixture.

Great results. I can forward you a thread if you want to read more on it.

since you seem to keep on top of your drain/refills - I would stick to that methodology, Do 3 drains and 3 refills, resulting in 9 quarts total fluid.

 

[fstime]

Not sure the answer to the OPs question but Amsoil ATF can be blended/mixed with Honda's Z-1 if you only want to do a drain and fill versus a full flush.

I used this a few years ago before DW1 was released and it worked great.

https://www.amsoil.com/storefront/atf.aspx

I did 2 more drain and fills after every 3,000 miles or so that ~85% of the fluid was replaced. I also recommend changing the AT filter and removing the drain plug on the torque converter if there is one to get more fluid out. If you change the filter, you might as well replace the gasket as well.

 

[Zivic]

If you're swapping over to a new fluid I would suggest a real flush, not just a drain and fill.

I wouldn't second guess what Honda recommends either, they generally have the act together.

honda doesn't recommend a "real flush". they advise against introducing pressure to the trans. the 3x fill/drain is proper procedure for many newer honda trans.

 

[Zivic]

Not sure the answer to the OPs question but Amsoil ATF can be blended/mixed with Honda's Z-1 if you only want to do a drain and fill versus a full flush.

I used this a few years ago before DW1 was released and it worked great.

https://www.amsoil.com/storefront/atf.aspx

I did 2 more drain and fills after every 3,000 miles or so that ~85% of the fluid was replaced. I also recommend changing the AT filter and removing the drain plug on the torque converter if there is one to get more fluid out. If you change the filter, you might as well replace the gasket as well.

I also recommend amsoil.

a trans flush is easy.... drain the trans, refill, drive the car for a couple miles at speed 50+, go back and repeat two more times. This will remove 80-some % of the fluid in the trans including the tq converter

 

[JCH13]

honda doesn't recommend a "real flush". they advise against introducing pressure to the trans. the 3x fill/drain is proper procedure for many newer honda trans.

:thumbsup:

 

[bigi]

honda doesn't recommend a "real flush". they advise against introducing pressure to the trans. the 3x fill/drain is proper procedure for many newer honda trans.

Correct. Anything that uses externally applied pressure is not advised.

I tap into tranny cooler return line and fill in on the other side, usually the dipstick hole. Run the engine to "flush" out the old fluid out and fill new one.
Each turn gets about 3qts replaced. 1, 2, 3 ... check final fluid level, done.

 

[Zivic]

Correct. Anything that uses externally applied pressure is not advised.

I tap into tranny cooler return line and fill in on the other side, usually the dipstick hole. Run the engine to "flush" out the old fluid out and fill new one.
Each turn gets about 3qts replaced. 1, 2, 3 ... check final fluid level, done.

but unless you drive the car to engage the tq converter, you will not be replacing any in the tq converter.

 

[JCH13]

but unless you drive the car to engage the tq converter, you will not be replacing any in the tq converter.

Hold down on the brake, shift into drive, and mat the accelerator. That'll clean out the torque converter.*







*Don't actually do this.