Quarts of ULV per Fitzstick Graduation?

[harringtondav]

Food for thought:

The coefficient of thermal expansion (CTE)) of ULV is very low, approx 0.0008/C°. If you start with 65°F(18.3°C) fluid, then warm the trans up to 215°F (101.7°C), the formula is as follows: [CTE x volume x delta T° = delta volume]

0.0008 x 7.2qts x (101.7°C - 18.3°C) = .480qts.

So if the 10R80 cold fluid capacity is 7.2qts, then that means it's designed to operate with 7.7qts at operating temperature (195°F - 215°F). But remember the torque converter can hold up to 2qts by itself.

The Fitzstick installation video was helpful. At the end the installer demonstrated sump level changes by taking a cold, engine off reading on the stick. After a 30 minute warm up he measured again at idle. The measurement was lower. The trans drains some fluid back into the sump when the truck is off.
So there are two variables. The drop in sump level when running, and the thermal expansion you state.
After I get it dialed in I'll be good until the next fluid change, baring a leak. ATF doesn't go out the exhaust like engine oil.

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[TJC]

The Fitzstick installation video was helpful. At the end the installer demonstrated sump level changes by taking a cold, engine off reading on the stick. After a 30 minute warm up he measured again at idle. The measurement was lower. The trans drains some fluid back into the sump when the truck is off.
So there are two variables. The drop in sump level when running, and the thermal expansion you state.
After I get it dialed in I'll be good until the next fluid change, baring a leak. ATF doesn't go out the exhaust like engine oil.

I have found that the fluid continues to drain into the pan for several days. If I pump it out over night I'll only get ~5 quarts. If I wait 3 days to pump out the fluid I'll get 7.5 qts.

I even pumped in out on consecutive days, 1st day ~5 qts, 2nd day ~1 qt, 3rd day ~1 qt. I did not wait a 4th day. But when I pulled the pan on the 3rd day I got another qt from the pan, and more when the filter was removed.

You can not accurately check your fluid level statically. I've let my truck sit for 2 weeks and found the fluid level above the scale on the dip stick. The fluid slowly drains out of the transmission into the pan. I am sure some stays on the converter and elsewhere. But there is enough that does drain to make a definable repeatable process difficult to implement.

When I was training AI and Knowledge Based systems in the 1990s at IBM Research, I learned to utilize and embed heuristics into the models. Rules of thumb that apply to a given situation 90+ of the time. People in all the trades utilize them all the time without even thinking about them..

There is a wide enough variance in the fluid level as measured between 4 and 5 at 205F-215F to solve the using heuristics. We just need to find the right rule of thumb to do it.

That is what I attempted to do with my timed measurements. I then refined/simplified it even more by (over night engine cold) measuring upon startup and shifting through the gears. If you see 1/8"- 3/16" of fluid on the dip stick tip you should be well within the range of 4-5 at 215F. Timing is critical. Measure immediately after the shift cycle - from park to sport back to park at 5 second intervals. then immediately measure. I had my hood up and step stool in place before I began. I don't know if it matters or not but my AC was on during all of my measurement tests
(only because I never turn it off).

I make several assumptions. I tested at 75F ambient air temp, Fluid was at 77.4F before the truck was started. You should be good measuring at anywhere from 65F-85F ambient air temp. (+-10F from my starting point of 75F). IF your truck is function properly your transmission temps when the fluid is fully warn will be in the 180F -200F range. Your dip stick level should read at 5+/- one hash mark. If you had measured at the upper range of 215F your reading will be 1 hash mark above or below the diamond between 4 and 5. Well within the 4-5 range at 215F.

This is based upon my findings. I present my theory to the group for validation. This process works for me, but the proof is in the pudding. It remains to be seen if the rule of thumb can stand the rigors of group testing with all the variables involved.

My original objective was to define a process where an owner can accurately reach the Ford Specified fluid level window at 215F without the need of a temperature measuring device, quickly and easily.

Here's hoping that the process does just that.

 

[harringtondav]

I just got it dialed in. I rechecked the level cold and engine off. The bottom graduation had fluid. I drove it for a warm up. Today I had both windows down and could hear the solenoids chattering/buzzing. The hot, running recheck showed a dry dipstick.
A slow add of 44 oz brought the level to the target 4/5 reading. Per previous comments 4 oz raises the level about one number. Final test drive had no solenoid noise.

 

[HeatXfer]

The post has been deleted. Please read this one:

https://www.ranger5g.com/forum/threads/quarts-of-ulv-per-fitzstick-graduation.36239/post-782903

 

[harringtondav]

So my final answer to the original question is 6.4oz per graduation:

4 grads between numbered marks = .3125 ÷ 4 = .078"
10.25" x 14.5" x .078" = 11.6in³. 11.6 ÷ 57.75 = .20qts = 6.4oz.

This can be calculated to a finer degree, but I'm stopping here.

I remember your earlier post. ....couldn't remember if it was 4 or 6 oz. I'm a bit dyslexic and 6.4 is trouble for me. I didn't titrate the fluid, I looked at the graduations on the bottle to get an idea. I'll go with your 6.4.

After I was finished I realized I missed an opportunity to measure the distance from the bottom of the dipstick to the pan joint. Before I added the last 44 oz it was clear the filter intake wasn't getting all the fluid it wanted.

 

[got3fords]

I'll add another data set here, bear with me on this:

Please correct me if I'm wrong, but I measured the distance between marks 4 to 5 on the Fitzstick @ 5/16". The stock trans pan is 10¼" x 14½", not including the sloped area at the rear. If we add fluid to raise the level from 5 to 4 on the Fitzstick, we've raised the height of the fluid by approx 5/16" (.3125") So, 10.25" x 14.5" x .3125" = 46.44in³ in fluid volume change. The volume of 1qt = 57.75in³.

46.44in³ is approx 80% of 57.75in³ (1qt) so that's .8qts per .3125 change in fluid height, i.e. marks 5 to 4 and vice versa.

This exercise does not take into consideration the total system volume, just fluid volume changes in relation to changes in fluid height.

Ultimately this info is useful when adding or removing fluid to attain the desired level as determined by the Fitzstick.

So my final answer to the original question is 6.4oz per graduation:

4 grads between numbered marks = .3125 ÷ 4 = .078"
10.25" x 14.5" x .078" = 11.6in³. 11.6 ÷ 57.75 = .20qts = 6.4oz.

This can be calculated to a finer degree, but I'm stopping here.

Damn, why does this have to be so complicated? Can't we just get the fluid approximately right and not worry about it. Why does it have to be so exact?

 

[harringtondav]

Damn, why does this have to be so complicated? Can't we just get the fluid approximately right and not worry about it. Why does it have to be so exact?

I agree. IIRC the Ford service manual specs 11.5 qts. ...mystery meat to most of use who never fully drain a trans.
My theory is the sump level needs to be high enough to keep the pump inlet filter submerged under extreme hill conditions, but not so high to flood the planetary rotating group and cause foaming.
My useless factory dipstick is still on the bench. Sometime I'll check the manual and see if it deciphers the graduations for max/min fill levels. I'd guess it translates to a reasonable variation in level.

 

[HeatXfer]

Damn, why does this have to be so complicated? Can't we just get the fluid approximately right and not worry about it. Why does it have to be so exact?

I don't think it does. Just know that if your Fitzstick reads right at 3.5 when hot, you're probably about a quart over; if it reads 5.5, you're probably about a quart low.

I often overthink things, but a main component of my previous life was failure analysis. Gathering as much background as possible on an issue to determine cause and correction is just how I do things. How I arrive at my conclusions may not be important to most people, but I always like to be able to show how I arrived at an answer even if I didn't need to. ?

 

[Langwilliams]

I overthink this crap, do short fluid change intervals then turn around and trade it in before 50K! I keep telling myself "this is the one I keep for ten years" but it hasn't happened.

 

[TJC]

I still have my 2005 4x4 Ranger Edge and it runs great. I keep my autos a LONG time.

I am a tad worried that this won't hold true for my 2020 Ranger, but not for a lack of trying!

 

[Fitzmotor]

I'll add another data set here, bear with me on this:

Please correct me if I'm wrong, but I measured the distance between marks 4 to 5 on the Fitzstick @ 5/16". The stock trans pan is 10¼" x 14½", not including the sloped area at the rear. If we add fluid to raise the level from 5 to 4 on the Fitzstick, we've raised the height of the fluid by approx 5/16" (.3125") So, 10.25" x 14.5" x .3125" = 46.44in³ in fluid volume change. The volume of 1qt = 57.75in³.

46.44in³ is approx 80% of 57.75in³ (1qt) so that's .8qts per .3125 change in fluid height, i.e. marks 5 to 4 and vice versa.

This exercise does not take into consideration the total system volume, just fluid volume changes in relation to changes in fluid height.

Ultimately this info is useful when adding or removing fluid to attain the desired level as determined by the Fitzstick.

So my final answer to the original question is 6.4oz per graduation:

4 grads between numbered marks = .3125 ÷ 4 = .078"
10.25" x 14.5" x .078" = 11.6in³. 11.6 ÷ 57.75 = .20qts = 6.4oz.

This can be calculated to a finer degree, but I'm stopping here.

Wait!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

That is a beautiful calculation...., but wait, the pan is full of valve body as well, there is more valve body in a stock pan than fluid probably.

If you add a quart for being a number low, you will way overfill it.

I suggest adding 6-8oz per number... then check it, add if needed.

It's like I said before, I did try to get a read on this, it seemed the 5-6 took more fluid than the 4-5, but it was a difficult thing to get right, I think I will need to put a valve on the pan drain, then keep letting a little out at a time to perform a proper test.

You guys, I so appreciate all the input, but calculations are only as good as the data used to make them, and the pan volume is part fluid, part valve body, very difficult to calculate accurately.

 

[Friday yet?]

Food for thought:

The coefficient of thermal expansion (CTE) of ULV is very low, approx 0.0008/C°. If you start with 65°F(18.3°C) fluid, then warm the trans up to 215°F (101.7°C), the formula is as follows: [CTE x volume x delta T° = delta volume]

0.0008 x 7.2qts x (101.7°C - 18.3°C) = .480qts.

So if the 10R80 cold fluid capacity is 7.2qts, then that means it's designed to operate with 7.7qts at operating temperature (195°F - 215°F). But remember the torque converter can hold up to 2qts by itself - that's probably why we typically see about 5½qts when we drain the transmission.

 

[Friday yet?]

This thread is a good example of why I have checked the fluid level maybe twice since I’ve installed the fitzstick.

man oh man, can I just have knobs, switches and simple to measure dip sticks and fluids?

I know I know… I’m sounding old. But damn come on.

Gotta run. Those dang kids are walking on my lawn again.

 

[harringtondav]

I still have my 2005 4x4 Ranger Edge and it runs great. I keep my autos a LONG time.

I am a tad worried that this won't hold true for my 2020 Ranger, but not for a lack of trying!

I'm a tight a*s, and retired my last two vehicles after 21 yrs. ...snaggle tooth rusty, but solid mechanically. I don't plan on getting rid of my Ranger until it's just as old, or if I die first. If the 10R80 pukes and the repair exceeds the truck's value I'll probably reconsider.

 

[harringtondav]

man oh man, can I just have knobs, switches and simple to measure dip sticks and fluids?

I heard that Beemers and/or Audis don't have engine oil dipsticks. Apparently there is a oil level sensor in the sump. ....no thanks.

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