Transmission Fluid Check How-To (Not Fun)

[krisk]

For anyone who has thought about checking the transmission fluid in their 10r80, I’ll let you know it is not fun. I changed out my transmission pan for one that has a plug so I can regularly change my fluid since I am tracking my car. I have the shop manual which says the initial fill after dropping the pan is 5 quarts, but just to be safe and possibly keep from having to add any extra fluid, I measured what I drained out of the car. In total, I measured 7.5 quarts drained. There may have been another 1/2 quart that dripped on the floor, stayed in my drain pan, etc., but likely less than that. So in total it was under 8 quarts drained from the car. As an initial fill I added 7.5 quarts. None of the work up to this point was too terrible.

The fun part is getting the transmission up to 206-216 degrees, getting underneath the car, unscrewing the dipstick cap, which is right next to the catalytic converter, then reinserting and removing the dipstick to read the level. Fortunately, I was prepared as I had two heat resistant Kevlar gloves/sleeves, a flexible head extra long ratchet wrench, a fluid pump and an extra long pair of needle nose pliers. Plus, I have a lift, so at least I wasn’t crawling on my back under the car. Even so, it was a pain.

In my case, even after the 7.5 quart fill, the fluid wasn’t even registering on the dipstick. I ended up adding another 1.5 quarts to get it between the 4 & 5 mark. I’m glad I measured what came out and refilled it with 7.5 quarts initially, because if i had followed the service manual I would have been 4 quarts low when driving it around to warm up.

A couple of comments for anyone who is planning to check their fluid. 1. The service manual shows using a socket, universal joint, and extra long socket extension bar stuck from the bottom of the car up through the engine bay and then using a socket wrench from the top to loosen the dipstick cap. That was my intention until I looked up from the bottom of the transmission and couldn’t even see daylight through the engine bay. It would have been a nightmare to do it the way they suggested. Fortunately I had an extra long flexible head 19mm ratchet wrench, which made it fairly easy to loosen from underneath the car. 2. Get some heat resistant gloves/sleeves. I was able to use the wrench to loosen the cap and the needle nose pliers to grab and remove it, but I still had to get my hand up in there to loosen it fully.

Overall, it’s not a fun experience, but is doable. Now that I’ve done it once it won’t be quite so bad next time, but it’s not something I’m looking forward to.

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[S650sunshine]

Thank you sir.

 

[Frogdog1]

The people that engineer this kind of thing should have to change the fluid 100 times. There's always an easier way.......thanks for the heads up!

 

[Junkyard Dog]

This post makes me wonder whether Ford fills it all the way up from the factory. It is not like you leaked 4 quarts of transmission fluid (or 2 quarts?) from your race car but were unaware it happened. You can see in the pictures it is dry under there.

Most folks, me included, have discovered that Ford under fills the engine oil from the factory.

 

[krisk]

This post makes me wonder whether Ford fills it all the way up from the factory. It is not like you leaked 4 quarts of transmission fluid (or 2 quarts?) from your race car but were unaware it happened. You can see in the pictures it is dry under there.

Most folks, me included, have discovered that Ford under fills the engine oil from the factory.

Based on my fill, I estimate it was just over one quart low from the factory. I filled it will nine quarts, but I only measured 7.5 quarts that I drained out. And yes, that picture was before I dropped the pan and it was completely dry under there with no sign of any leaks. However, I did install an aftermarket pan, but it was not one that had an increased fluid capacity, so I expect it would hold exactly the same amount of fluid as the OE pan, but there could be some variation which may account for some of the fill difference amount.

 

[Zig]

Based on my fill, I estimate it was just over one quart low from the factory. I filled it will nine quarts, but I only measured 7.5 quarts that I drained out. And yes, that picture was before I dropped the pan and it was completely dry under there with no sign of any leaks. However, I did install an aftermarket pan, but it was not one that had an increased fluid capacity, so I expect it would hold exactly the same amount of fluid as the OE pan, but there could be some variation which may account for some of the fill difference amount.

Don’t forget the torque converter retains fluid.

 

[Junkyard Dog]

Don’t forget the torque converter retains fluid.

But that does not have anything to do with the fill level on the dip stick after he has filled it and driven it to get it hot and then rechecked it, right?

 

[krisk]

Don’t forget the torque converter retains fluid.

The torque converter as well as the transmission cooler and lines retain fluid. Per the owners manual all variants have a 13.1 qt transmission fluid capacity, and per the repair manual all have a 13.0 qt capacity. However, I don't know how there couldn't be a difference for the the DH/PP models as compared to non PP models as the DH/PP have a transmission cooler whereas the other models do not. Regardless, the total capacity is somewhere around 13 qt. I drained approximately 7.5 quarts and filled 9, so I figure there's somewhere between 4-5.5 quarts of the original fluid that was retained in the torque converter and cooler after I drained and refilled it.

 

[Zig]

But that does not have anything to do with the fill level on the dip stick after he has filled it and driven it to get it hot and then rechecked it, right?

the fill level (assuming it has also passed through the gears - manually place into each gear, etc) will indicate the proper level but assumption based upon amount collected from the pan during drain may be off a tad.

 

[krisk]

But that does not have anything to do with the fill level on the dip stick after he has filled it and driven it to get it hot and then rechecked it, right?

It shouldn't. If the amount drained was exactly the same as the amount filled (which would be nearly impossible to get exact), the dipstick should read identically before and after, regardless of whether fluid is retained in the torque converter or anywhere else. I did not check the fluid level prior to changing the fluid because it would have only been for curiosity sake, and as much of a pain as it was to check, I didn't feel like the extra trouble was worth it.

 

[Zig]

The torque converter as well as the transmission cooler and lines retain fluid. Per the owners manual all variants have a 13.1 qt transmission fluid capacity, and per the repair manual all have a 13.0 qt capacity. However, I don't know how there couldn't be a difference for the the DH/PP models as compared to non PP models as the DH/PP have a transmission cooler whereas the other models do not. Regardless, the total capacity is somewhere around 13 qt. I drained approximately 7.5 quarts and filled 9, so I figure there's somewhere between 4-5.5 quarts of the original fluid that was retained in the torque converter and cooler after I drained and refilled it.

Sometimes multiple drain and refills are needed in order to replace all of the fluid.

 

[krisk]

Sometimes multiple drain and refills are needed in order to replace all of the fluid.

I plan to drain and refill every other track weekend to coincide with the fluid change in the axle. Assuming a 13.5 total capacity (allowing for more than specified in the manual to account for the cooler), with a 9 quart drain and fill, that is exactly 2/3 of the total fluid drained each time. The calculation is exactly 2/3, but the actual amount drained is just an estimate which should be somewhere in that neighborhood.

After the First Change: 66.7% of the original fluid has been removed
After the Second Change: 88.9% of the original fluid has been removed
After the Third Change: 96.3% of the original fluid has been removed

So, by the third change, I should have less than 5% of the factory fill of transmission fluid left. I've heard some bad things about attempting to completely flush the fluid, so I think the draining and refilling every 500 or so track miles should be good enough since I'm getting about 2/3 of the total fluid out of the car with each change.

 

[Neggytive]

too bad the replacement pan was not a "bottom fill" type. A drain plug to drain it and a stand pipe to reflll it.

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