Just began to service my transmission and found that I only drained a little less than 3 quarts after removing the pan. I have read that you should need 6-7 quarts when replacing the filter. I have seen tranny temps of close to 260 degrees in 100 degree weather and in traffic. Can't believe that I have been three quarts low and had good transmission functions. Anyone else had this experience of only losing 3 quarts of oil?

 

What color was the fluid when you drained it? I don't see how you could have lost that much without knowing about it.

 

The oil was some what dark, but didn't smell burnt. I definately didn't lose any fluid, the tranny is perfectly dry. Could only have been low from the factory, but it work with 3 quarts low?

 

blown34

Mine was low once due to a leak from 1 of my trans cooler fittings, trans acted weird from a stand still, like there was no gear there, and then somewhat harshly go into gear. I have changed my trans fluid twice in 32K and never seen it anything but bright red.

 

This is my first change in 48K miles and I've burnt up 3 sets of rear tires and driven it to Florida, so I can't expect it to be bright red.

 

I thought the 6L80 needed special equipment to change fluid?

 

Not at all!

 

Assuming you have a stock converter, I'd suspect a leak somewhere. Possibly in the radiator, but more likely in the lines somewhere. 260 degree fluid in 100 degree ambiant is way too hot.

Consider driving it a few hundred miles and changing it again to remove more of the old fluid.

 

It seems odd that you could have lost 3 qts and that you don't see any mess and that it shifted fine at WOT. IIRC, the 4L60 needed to be tilted to get a lot of the fluid out. Is that needed to drain the 6L80?

Pulling the pan won't get the fluid in the converter or the cooler lines; was included in the 6-7 qt estimate?

 

Ragtop is entirely correct. Draining the flluid will only get about half of the fluid. The rest is in the torque converter. To fully replace all fluid you need a power flush. With the engine running and the A6 in gear, fluid is added while the old is removed. Often done using the cooling lines. Last time I did this on my A4 (2000) it cost about $100. Well worth the cost in my opinion.

 

Have mine done every 30K. The machine takes about 14 quarts to do a good transfusion.

 

Factory says that it should take 6-7 quarts when replacing the filter; I removed 3 quarts and car has never leaked anything; the only conclusion I can reach is that it was 3 quarts low and that is why I ran such high oil temps in the summer. Just find it hard to believe that the trans would function properly when 3 quarts low.

 

My 2005 service manual (A4) shows fluid capacity spec as 5 quarts oil pan removal and 10.8 qts overhaul.

Without any leaks present, check for oil in the coolant too, can't advise.

Just add the replacement oil through the access hole as the procedure outline (car running etc) and maybe recheck in a month to see if any fluid was again lost.

I'd probably not worry about only getting 3 quarts out at this time.

 

The "flush" service only replaces half the fluid just like dropping the pan. Drop the pan and change the filter like you should do anyway.

You'll never "fully" replace all of the fluid unless you completely disassemble the transmission. If you're not fully aware of all of the hydraulic circuits and the flow paths of the fluid, you'll never understand why "flushes" are a gimmick and the shops pushing the service are depending on your ignorance.

 

The worst part about most Jiffy Lube style 'flush' situations is that they do all of that fluid pumping and in almost every case the pan is never even dropped during the process resulting in an original (dirty/potentially clogged) filter and pan gasket still on the car.

 

Guess we'll disagree on this one. With the transmission operating in gear, the fluid is flowing thru all the "hydraulic circuits and flow paths". Adding new fluid while the old is draining will replace most of the old fluid. MHO.

 

i've done a flush on my accord and it would only drain 3 qts at a time. I would have to drain 3 qts, fill up 3, then drive around, then drain another 3, fill another 3, drive around again, drain 3 and fill 3. By then the fluid will be more or less "new"

 

The 4 speed auto is not relevant to this topic.

The A6 holds about 12.6 quarts in the entire system - including the Torque Converter, cooling lines, cooler, etc. etc. In other words, 12.6 quarts is a dry fill. That's why a flush takes about 14 quarts.

The manual states that 6-7 quarts is normal for a drop the pan/filter change only.

To the OP - Did you check fluid level (using the approved - painful - procedure) before you drained the 3 quarts?

Also to the OP - Have you pulled the filter yet - you'll get more ATF out when you drop the filter (although another 3-4 quarts seems unlikely).

 

Not sure how many quarts the Accord tranny holds, but your method, while better than nothing, is not a more of less replaced method, it is a "drain and fill", and far less efficient than replacing all at once and does not come close to replacing all the fluid. That said, it's better than ignoring your tranny, and the preponderance of fresh fluid, although now somewhat contaminated, and combined with old fluid, is better than leaving all the fluid in until it breaks down/dumps out.

If your Accord tranny holds 12 quarts, using the method you decribed results in a 25% replacement each time, followed immdiately by contamination of the new fluid. Three iterations of this method means not that you have replaced pretty much all of it, but that you have replaced a small percentage of it.

Still, I use that method for less critical systems (e.g. cooling system) but do it annually, repalcing about 1/3-1/4 of the fluid depending on which car/system it is.

 

You seem to know a lot about auto transmissions. Can you tell us how many checkballs are in the 6L80 as well as their location and functions? I'll give you a hint, it's a lucky number. Here's another hint, their all located in the same valve body...that gives you a 50/50 chance. Now what are their functions. I'll get you started...number 1 checkball blocks the drive braking passage and allows fluid to enter the 2-6 clutch/1-2-3-4 clutch feed circuit to apply the 1-2-3-4 clutch.

I'm glad you stated "MHO" at the end because what you said could not be farther from the facts. With the transmission in any gear (including park or neutral), the only circuits with flow are the pump, torque converter, and lubrication circuits.

Here are a few "snapshots" of the hydraulic circuits in the 6L80:









If you look at the 1st and 5th pictures, all the "white" lines represent circuits not used in 1st gear in park respectively. (I can post the circuits for all other gears if you want but these two are enough to demonstrate fluid flow or more specifically, the lack of fluid flow through the circuits.) With the exception of the pump/converter circuit to the far left of the picture and the lubrication circuits (represented by the red dotted lines) in the rest of the picture, no fluid is flowing even in the colored lines in the 75% of the picture to the left where the clutches circuits are. The same thing happens in all other gears...once the clutches have actuated, no more flow occurs and whatever fluid is in the apply piston stays. It should be noted line pressure applies the clutches while compensator pressure assists the release on the other side of the apply piston so fluid is actually "stagnant" on both sides of the apply piston. And let's not forget the torque converter clutch...it uses fluid to apply and release the clutch which remains stagnant until there is a change of state. If you look at all the other pictures which basically details the pump, torque converter, and cooler functions, you get an idea of how the fluid flows when you're idling in park (which is how they do the flush). The pump volume/pressure is at a minimum at this point so as the new fluid returns to the sump from the cooler (via the lubrication circuit), it has plenty of time to mix with the old fluid in the sump. As the "mixed" fluid is picked up and sent to the torque converter, it has plenty of time to mix with the old fluid not to mention the vanes in the torque converter do a great job of ensuring the new/old fluid get fully mixed. As you can see, a lot of the old fluid isn't even accessible and the old fluid that is accessible gets fully mixed with the new fluid quickly meaning you're lucky if you end up with a 50/50 mixture of old/new fluid when doing a flush. Dropping the pan gets you 6.5 quarts out of a 12.5 quart system which puts you just over 50% plus you get a new filter...all for less than the cost of a flush. More for less...seems like a no brainer to me. Like I said, the shops pushing the flushes are depending on the ignorance of the consumer and their sales ability...looks like you bought their sales pitch. To use 14 quarts in a "flush" to get to the same "old/new fluid" concentration as 6.5 quarts is a gross waste of oil too.

To add a little more, Allison Transmission has a service bulletin out that point blank states "Fluid exchanging machines are not recommended or recognized" for their auto transmissions due to incomplete fluid change.
http://www.allisontransmission.com/s...5&DownloadID=5

PS I'm not in disagreement with you, I'm in agreement with the facts...you can disagree with the facts if you want but the facts don't belong to me. If it just makes you feel better to do a flush, then rock on...I understand that concept completely.