I want to change the fluid in my Jeep Renegade (ZF 9 speed). Of course there's no dip stick so my plan was to see how much came out then add that much. Then I found instructions to do it correctly. There's a dipstick to buy and I would need to know the transmission temp to check it. Is it worth the bother, and if so what scan tool should I get to check. I'm pretty sure my cheepo HF one doesn't do this.
You can find the answer here: https://grassrootsmotorsports.com/forum/grm/automatic-transmission-scan-toolfluid-change/270722/page1/
In reply to Brett_Murphy (Agent of Chaos) :
Is the joke the link goes to this same thread?
In reply to Cyclone03 :
I wasn't sure, myself. 
I have no idea if this would apply to your transmission, but on the Mercedes 722.9 box, the official procedure is to look at the computer for the transmission fluid temp. There is a lot of Internet wisdom that hitting the pan with an infrared thermometer works just as well. Not sure if that's an option for your transmission, but worth a look?
I can't help but wonder how critical the temp actually is. Pretty much since the dawn of time the requirement has been to do your final check "hot". I strongly suspect that the only reason there's a more precise spec is that if you have a scan tool it's easy to read an actual number.
Maybe drain the fluid.
Let it come to the same temperature as the new fluid.
Measure the resulting volume of the old fluid.
Put that amount of new fluid into the transmission.
If you have a leaky transmission this won't work of course.
Not sure exactly how that trans is but in our old Town and Country (different trans but sounds like a similar situation) it only had a plug at the top of the trans. there was a 'service tool' dip stick you could buy online, but I found a youtube video of a guy who just used the oil dip stick to put into the trans and measured how far it was up the dip stick (which matched the height on the service dip stick) to check fluid level. The service dip stick did have different levels for different temps but I always just measured it hot while idling like pretty much every trans is measured at.
Wally (Forum Supporter) said:I want to change the fluid in my Jeep Renegade (ZF 9 speed). Of course there's no dip stick so my plan was to see how much came out then add that much. Then I found instructions to do it correctly. There's a dipstick to buy and I would need to know the transmission temp to check it. Is it worth the bother, and if so what scan tool should I get to check. I'm pretty sure my cheepo HF one doesn't do this.
I have a “scan gauge II” which has the ability to add (program) monitors (they call it x gauge). I use it to check atf temp range for fluid changes in my Kia. They list trans temp for the fiat 500/500x , so likely will work... X gauge . They cost about $130 at most retailers. I’m pretty sure it would work but maybe worth contacting them first to confirm.
For a Lexus I had I used an amazon sourced “tech stream” and cable, worked great for trans temp monitoring but only works well with Toyota products. That was about $60 + laptop, no idea if it would pick up fiat/Jeep/Chrysler specifics but doubt it.
It is possible some Bluetooth obd2 phone based apps can read the data but I have no personal experience, may be worth looking into.
good luck
I just did this on my wife's car with a ZHP8, I assume its similar.
- The pan is plastic and black, its hard to use an IR thermometer.
- It takes quite a bit of time for the transmission to reach the temperature.
- If you ignore the refilling at temperature, you will probably miss 50% of the fluid.
- If its like the ZHP8, then the filter is built into the pan, so change it.
- ZF has all the info on their website regarding bolt tightening sequence and torque.
There has to be an app that will read the trans temperature out there and can be used with a bluetooth dongle. You can probably let it run through the gears for 10-15' and be safe, but you will always wonder if you did it right.
APEowner said:I can't help but wonder how critical the temp actually is. Pretty much since the dawn of time the requirement has been to do your final check "hot". I strongly suspect that the only reason there's a more precise spec is that if you have a scan tool it's easy to read an actual number.
I'm not sure either but the tool is supposed to have different marks for different temperatures so I'm guessing there's something to it.
Wally (Forum Supporter) said:APEowner said:I can't help but wonder how critical the temp actually is. Pretty much since the dawn of time the requirement has been to do your final check "hot". I strongly suspect that the only reason there's a more precise spec is that if you have a scan tool it's easy to read an actual number.
I'm not sure either but the tool is supposed to have different marks for different temperatures so I'm guessing there's something to it.
ATF expands at a rate of 0.07% per degree c so it is important to check it hot but it's not important to have super high resolution on what hot means. However, bluetooth dongles are around $30 and you probably already have a cell phone to pair it with so assuming that the trans temp is available in the standard data stream it's worth the minor investment to be able to read it.
Slippery said:I just did this on my wife's car with a ZHP8, I assume its similar.
- The pan is plastic and black, its hard to use an IR thermometer.
- It takes quite a bit of time for the transmission to reach the temperature.
- If you ignore the refilling at temperature, you will probably miss 50% of the fluid.
- If its like the ZHP8, then the filter is built into the pan, so change it.
- ZF has all the info on their website regarding bolt tightening sequence and torque.
There has to be an app that will read the trans temperature out there and can be used with a bluetooth dongle. You can probably let it run through the gears for 10-15' and be safe, but you will always wonder if you did it right.
Apparently bluedriver app can not read trans temp. Apparently torquepro app can but you may have to add a “pid “ which I can’t seem to easily find if it exists for the Jeep/fiat.
My $19.95 dongle works just fine, although I've been warned it might not. YMMV.
In attempting to learn how to use TorquePro, I don't understand the whole "pid".
I've learned enough to use it on my 6.0 to measure the differential of the coolant temp and oil temp. And gustomzing the available data and gauges.
Making new data - way over my head.
I had a Honda that was shifting funky. I took it to the dealer and they said that it needed a transmission flush. I was surprised that it was only $99. It seemed totally worth it.
In reply to Woody (Forum Supportum) :
I'll call on Tuesday, for that price I don't need to learn how to do this.
I just did a drain and fill on my Hyundai. Youtube said to measure what comes out and put that much back in. Since I drained it at room temperature, and the new fluid was also, you guessed it, room temperature, I think I'm OK.
I hope I'm not wrong.
IIRC these are the funky things with nothing in the access hole for a dipstick to bottom out in like every other ZF made.
Every other ZF, you push something down until it bottoms out inside the trans then measure the fluid height from bottom. So of course they changed it. It can vary by tens of millimeters depending on temperature.
Overfilling sucks as much as underfilling, as aerated fluid does not cool very well, so overfull can lead to overheating. You can't go wrong with putting back in what you took out, though.
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