21 Honda Pilot ZF 9 Speed capacity discrepancy

[Owen Lucas]

3.2 quarts ATF 3.1 in 3 quarts out, where did the rest go? 21 Honda Pilot ZF 9 Speed

Replacing the fluid on my 21 Honda Pilot right now and I figured I’d do a transmission rinse before the final fill. I drained out 3500mL quarts into a graduated 5000 mL pitcher.

This is the ZF9 speed transmission, automatic all wheel drive.

The book states that the correct replacement fluid fill is 3.5 quarts, which is 3300 mL which is confusing why 3500 came out but I do have the car on ramps so maybe that affects how much I should be replacing?

For some reason, I filled it back up with only 3200 mL. I drove for about 3 miles and have drained the fluid back into the graduated pitcher but only 3000 came out.

I’m not sure if the torque converter is somehow holding this excess capacity or what happened but I am thinking of actually filling up with 3700 mL now considering the 200 mL discrepancy.

Let’s say I overfill by 200 mL instead of the 3500 mL fill which drained out initially, would overfilling by 200mL be an issue on a transmission that has a total capacity of 7.9 quarts (7500mL)?

 

[Owen Lucas]

Also, could I have caused any damage over the 3 miles by driving with 500 mL less ATF?

 

[Hall]

+200ml or -300ml is a non-factor

If you're on ramps vs level ground, that will definitely account for some discrepency. Doesn't that use a level plug ? If so, use it to set the level and be done with it. What comes out is just a starting point (on vehicles without dipsticks or level holes).

 

[Owen Lucas]

+200ml or -300ml is a non-factor

If you're on ramps vs level ground, that will definitely account for some discrepency. Doesn't that use a level plug ? If so, use it to set the level and be done with it. What comes out is just a starting point (on vehicles without dipsticks or level holes).

My concern using the level plug is that since the vehicle is on ramps that might throw off the true position of the correct fluid level considering the vehicle is at an angle. So since the vehicle is in pretty good shape at 50,000 miles, I don’t see any evidence of leakage. My goal is to restore the fluid that came out plus the fill level plug is in a real PITA location and it’s already cramped under the car lol.

 

[panthermike]

My concern using the level plug is that since the vehicle is on ramps that might throw off the true position of the correct fluid level considering the vehicle is at an angle. So since the vehicle is in pretty good shape at 50,000 miles, I don’t see any evidence of leakage. My goal is to restore the fluid that came out plus the fill level plug is in a real PITA location and it’s already cramped under the car lol.

Yes, only way to do this properly would be to put the rear on ramps/jackstands and make it level as possible. A lot of the time, I just drain/fill on a cold trans and it's always been fine.

 

[TomYoung]

If it's me, gotta consider 10% spillage on driveway, both in and out.

 

[Sayjac]

.....The book states that the correct replacement fluid fill is 3.5 quarts, which is 3300 mL which is confusing why 3500 came out but I do have the car on ramps so maybe that affects how much I should be replacing?.....

If by ramps you mean front ramps only, could well be a factor. In fact I'd say probable. When I do ATF and CVT fluid d&fs on my Hondas, I put front wheels on ramps only to break the drain plug loose, but keep it from leaking. Then take vehicle off the ramps to level, drain and refill, check level and if possible retighten drain plug to spec. Sometimes depending on vehicle, possible to break drain plug loose without ramps. No matter what though, do as much as possible with a level vehicle.

 

[Owen Lucas]

OK accessing the fluid check bolt won’t be as hard as I think. I just have to take the driver side front wheel off.

As long as I can lower the vehicle on the jack back to a level height, then I think I will be able to access it.

From my understanding, I’m supposed to fill the transmission until it trickles out?

 

[TomYoung]

Also, could I have caused any damage over the 3 miles by driving with 500 mL less ATF?

No

 

[BornSlippy]

Is the Pilot that low to the ground? I was able to get under our Escape on level ground with a drain pan and pull the drain plug. 4.5 qts is what was suppose to come out, and that is what I got out of it and what went back in four times.

Also, if the fluid has never been touched, it may have come from the factory a little low on fluid. I would try getting at the drain plug while it's on level ground. The procedure for checking the fill level is the same, pull the plug on the side of the tranny right beside the axle. I wasn't too excited about pulling the wheel off to get it.

I don't think the tranny will drain all it could drain out if it was sitting on level ground vs. sitting nose high on ramps.

 

[Owen Lucas]

The ramps add 7” in height.

 

[BornSlippy]

Sitting that nose high, I would guess all the fluid isn't coming out. I would add back in what you got out. There is quite a bit of area behind the drain plug that fluid will pool in and gravity doing it's thing, the fluid isn't going to flow uphill to the drain plug. It's not like an oil change where 99% of the time the drain plug is at the rear of the pan.

If you go with the level check plug on the side, the fluid probably has to be "checked" between a certain temperature range. On some transmissions that range is quite narrow and it overshoots very quickly.

 

[Nukeman7]

That's not the ideal method to do a ATF drain and refill on a Honda. You should also jack up the rear end and place it on jackstands so the Pilot is horizontally level. Always remove the upper fill plug before removing the lower drain plug (both will be very tight from the factory). Drain out as much you can (just like an oil change), then replace the lower plug. Rig up ~4 feet of clear Tygon tubing to a funnel and suspend the funnel at fender height or have an assistant hold it. Insert the lower end of the tubing in the fill hole and slowly fill ~3.5 quarts of Honda DW-1 ATF until it begins to overflow. Remove tubing, wipe up any spillage and reinstall the fill plug. It is much easier if you have a fill pump similar to the LUMAX LX-1341.

 

[Owen Lucas]

Sitting that nose high, I would guess all the fluid isn't coming out. I would add back in what you got out. There is quite a bit of area behind the drain plug that fluid will pool in and gravity doing it's thing, the fluid isn't going to flow uphill to the drain plug. It's not like an oil change where 99% of the time the drain plug is at the rear of the pan.

If you go with the level check plug on the side, the fluid probably has to be "checked" between a certain temperature range. On some transmissions that range is quite narrow and it overshoots very quickly.

That is my concern. It appears that the the trans does indeed have to be hot and specifically 104°. Well, I leveled off the vehicle and will change the check bolt. I have no way to confirm the temperature of the car as my contactless thermometer is out of commission. Let’s see what happens.

 

[Owen Lucas]

That's not the ideal method to do a ATF drain and refill on a Honda. You should also jack up the rear end and place it on jackstands so the Pilot is horizontally level. Always remove the upper fill plug before removing the lower drain plug (both will be very tight from the factory). Drain out as much you can (just like an oil change), then replace the lower plug. Rig up ~4 feet of clear Tygon tubing to a funnel and suspend the funnel at fender height or have an assistant hold it. Insert the lower end of the tubing in the fill hole and slowly fill ~3.5 quarts of Honda DW-1 ATF until it begins to overflow. Remove tubing, wipe up any spillage and reinstall the fill plug. It is much easier if you have a fill pump similar to the LUMAX LX-1341.

Yep, I realize I am filling it wrong now. Who would’ve thought that you fill it through the check bolt not through the supposed fill hole on top of the transmission.

 

[BornSlippy]

No trans temp on the dash?

 

[Owen Lucas]

No trans temp on the dash?

No, all digital. I pulled the plug and 800mL came out.

I filled it back up with the original drain, can’t go wrong with replacing the same amount that came out.

 

[Tortuga]

The ramps add 7” in height.

View attachment 281602

I have two sets of those ramps. I put one set in front of each axle and drive up on it. That way everything is level for drain and refill. You can access the check bolt from underneath this way without removing the wheel.

I got almost 5 quarts out of mine when I serviced it. I think the dealer overfilled it when they installed the replacement transmission at 130k miles. I put 4 quarts back in and it shifts great. I also used a long funnel and the top plug to fill instead of the check bolt. The manual says 3.5 quarts are needed for a drain/fill.

I have five quarts of Pentosin ATF9 on the way from Rock Auto ($18/quart vs dealer $30). I’m going to do another drain/fill. I’ll probably refill via the top bolt again so I can use a funnel, but I’ll remove the check bolt to do a level check when it’s warming up. .

 

[The Critic]

No, all digital. I pulled the plug and 800mL came out.

I filled it back up with the original drain, can’t go wrong with replacing the same amount that came out.

View attachment 281641

Actually, you can. Expansion rate of hot fluid.

 

[Owen Lucas]

Actually, you can. Expansion rate of hot fluid.

That must explain why so much of the fluid was coming out after I ran the engine for a while. The initial 3500 mL drain was achieved on a cold transmission so I am more confident now that I used the correct amount.