How to measure transmission temp when changing fluid/filter?
#1
How to measure transmission temp when changing fluid/filter?
I'm planning on replacing the transmission fluid and filter on my 2009 XKR this weekend. How do I accurately measure the temp of the fluid to make sure it's between 30 and 50C during the level check?
I see some are using a non-contact thermometer on the pan, but how accurate is that with a plastic pan?
On my Lexus, I was able to hook up my code scanner and read the trans temps. I tried it last night on my Jaguar and it wouldn't show trans temp. Is there a specific scanner that's recommended?
Does anyone have a been-there-done-that solution?
I see some are using a non-contact thermometer on the pan, but how accurate is that with a plastic pan?
On my Lexus, I was able to hook up my code scanner and read the trans temps. I tried it last night on my Jaguar and it wouldn't show trans temp. Is there a specific scanner that's recommended?
Does anyone have a been-there-done-that solution?
#6
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#9
Its more than a few drops. Think about a car with a trans dip stick and the cool reading and hot reading. The difference is the volume of fluid in the pan.between cool/cold and hot.
#10
I'm glad you brought that up though.....
What's the range on a dipstick transmission between ADD and FULL??? About an inch??? I really don't think even an ounce more or less in a ZF is going to do anything. If the fluid level was THAT super-critical, the change would have to be done at a laboratory, in a hyperbaric chamber, air filtered, at sea level, humidity-controlled, float-leveled, and at midnight on a new moon.
Last edited by Cee Jay; 05-22-2019 at 11:25 AM. Reason: logic
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riverman (06-01-2019)
#11
Yes, and that's after so much of the fluid gets coated around parts and pipes.
#12
I cut a small piece of hex head wrench off (3/4"?) using a hacksaw and stuck it in the cap using some thick grease, which held it in place allowing me to screw the plug in enough with my gloved fingers.
It's the little things that make this job easier and 95+% of the guys on this forum will outsource the work, which is understandable. I have a lift so not that big of a deal but I admire the ones who tackle it on Jack Stands.
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kj07xk (05-22-2019),
Queen and Country (05-22-2019)
#13
If I know that I performed the transmission fluid flush and fill correctly I would have 100% confidence with my work. The ideal temp being 40 C according to ZF.
Last edited by jackra_1; 05-22-2019 at 12:35 PM.
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Queen and Country (05-22-2019)
#14
Coefficient of thermal expansion for oils and transmission fluids is around 0.0007 per degree C (0.07%/C).
Me adding Trans Fluid to every Dipstick vehicle I own for my entire life----- "Meh, about half a quart should do fine.... 'glub-glub-glub'..... There we go..."
Four ounces (+/-, which could also be had by the vehicle being off-level by 1 degree either way) when the entire transmission and Torque Converter holds like fifteen quarts is less than 1 percent.
Now, can we get off this ridiculous subject and press on?
Me adding Trans Fluid to every Dipstick vehicle I own for my entire life----- "Meh, about half a quart should do fine.... 'glub-glub-glub'..... There we go..."
Four ounces (+/-, which could also be had by the vehicle being off-level by 1 degree either way) when the entire transmission and Torque Converter holds like fifteen quarts is less than 1 percent.
Now, can we get off this ridiculous subject and press on?
Last edited by Cee Jay; 05-22-2019 at 01:17 PM.
#16
There is a simpler math; every manufacturer in the world, for decades, makes a big fuss about the difference between hot and cold ATF measurement. i.e. a non-negligible amount. You can believe them or....
There is a much more simpler math, they know nothing!
There is a much more simpler math, they know nothing!
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jackra_1 (05-22-2019)
#17
Did I SAY it was wrong??? No. I said it was Insignificant. An eighth of a quart. I sneeze out that much snot on a bad day.
#19
I've changed my mind on this. I've been using the Torque app and it appears as if the transmission temp it shows is really just the engine coolant temp.
#20
https://www.jaguarforums.com/forum/g...p-more-213503/