Seeking advice: Transmission temperatures, towing, and the transmission fluid vent

[jas]

I wasn't sure if this belonged under towing or general since I've got a couple of questions here, so if this needs to be moved, please do so.

Bit of a backstory: We got our 2019 XLT FX4 supercrew w/ factory tow hitch back in September with only 10k miles on it, mainly as a replacement for our 2014 2.0 4WD Escape since our Jayco 154BH travel trailer was too much for it. (Let's just not talk about me initially being ignorant about the Escape's frontal area consideration and specific axle ratings). We negotiated to have the Redarc brake controller from Ford installed along with some side steps.

We took a trip this summer before we got the Ranger and we used my dad's 2019 King Ranch F150 crew cab to tow the trailer and it towed wonderfully. I had an OBDLink MX+, so I used it to watch the engine temps, boost level, and transmission temperatures while towing. I was initially surprised to see constant transmission temperatures over 200ºF. But the tow rating on the F150 was over 10,000# and it wasn't that old, so I wasn't too worried about it, plus there were no dummy lights or warnings showing up on the dash.

That brings us to this past weekend. We drove 2.5 hours out of town to a state park and camped there using the Ranger. Everything worked beautifully and we didn't have any issues. When watching temperatures coming back home, engine coolant and cylinder head temps were right at 200ºF and the transmission fluid temps were anywhere from 200ºF to 210ºF. At one point, I saw it peak around 215ºF. This seemed on par to what I saw in the F150, so didn't think anything about it. Plus back when it was 90+ºF outside, I saw the transmission temperatures in the Ranger hitting over 200ºF when not towing or hauling anything.

Well, when near home, I was getting back on the highway and had some cars fast approaching behind me, so I gave it a good amount of gas in 2nd gear to get onto the highway. I smelt something, but looked at the temperature gauges and dash and nothing seemed off at all. Took it easy the rest of the way home and everything seemed just fine. When I got back home and started unhitching the trailer, I saw some spatter on the front of the trailer and on the tailgate of the truck. I was able to trace it back to the transmission where I could see red liquid on the bottom of it. In talking to a Ford tech via a friend, they said it may have come from the vent. I was able to remove the mud guard from the passenger wheel well and get a camera up above the transmission and sure enough, it looks to have come from the vent.

I just dropped the Ranger off at a nearby dealership so they could check the transmission fluid level to make sure we're still good and check a couple of other fault codes I saw when scanning. The service rep was telling me that it most likely got too hot and vented. When asking what temperatures are normal for the transmission, he was saying it should stay around 180ºF and that if I'm going to be towing, I should get a larger transmission cooler.

I'm a bit miffed if the truck I got specifically to be able to tow with a capacity over twice what my fully-loaded trailer is would have issues if I ever had to hammer it down while towing. I don't see that as anything I'd do even semi-regularly, but I'd rather have the ability and know I can if I needed to.

So for the questions:

• What's a normal operating temperature for our transmission? Is 180ºF an old standard?
• What's "too hot" of a temperature for our transmission, towing/hauling/or not? I love to be able to add a redline on my gauge so I know what to watch for and when to start getting concerned.
• In the OBDLink app, they don't have Ranger listed as a vehicle (I've already contacted their support about this), but they have Ford/Lincoln/Mercury-specific enhanced OEM add-ons, and I've been setting it to a 2019 Ford Explorer with the 2.3l EcoBoost and everything seems to be working well. I'm using Transmission Fluid Temperature under Network A, Powertrain Control Module. Would that be a good source for transmission temps for our Rangers or is there something better?
• Are there Ranger-specific larger transmission coolers? Is a larger transmission cooler actually needed?
• Was it too hot and vented when I gave it some gas while towing or should I be looking at something else?
• Has anyone else had transmission fluid vent from the transmission and what were your circumstances?

Thank y'all!

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[jas]

let us know how much oil it vented. a little or alot would mean a whole lot to this conversation

all i know is optimol temps while towing are from 160-200.

Honestly not sure how much vented. I was going between 40 and 60mph when I think it happened. Here’s what it looked like underneath the next day. You can see where it got on the passenger side and on the gas tank.

And here was the vent:

I'll be interested to see what the dealership says and see how much fluid they had to replace.

As far as temps, the Ford tech I've been talking with via a friend said that 190ºF - 210ºF is normal operating temps for the transmission and a high temp would be 250ºF or more. I couldn't find anything online that was authoritative direct from Ford about temp ranges and normal operating temps.

 

[VAMike]

First rule is don't put more stock in information from a random guy at a dealership than information from the manufacturer. One of those entities has engineering data, test data, and fleet data, and one has anecdotes, personal bias, and bullshit.

 

[jas]

First rule is don't put more stock in information from a random guy at a dealership than information from the manufacturer. One of those entities has engineering data, test data, and fleet data, and one has anecdotes, personal bias, and bullshit.

Yeah, I definitely don't give any clout to what service reps tell me. I'll let them ramble on rather than argue with them. I figure it's not worth it. Actual Ford techs, I'll trust a bit more, but this same tech I've been talking with thought I was pushing the Ranger at it's "max" towing capability of 3500#. Had to make sure and correct that. That's why I was reaching out here. I think I'd trust this forum the most, just below verified documentation direct from Ford, which I haven't been able to find.

 

[VAMike]

Quick answers to the actual questions are: 180 degrees is just wrong, all the new transmissions run hotter than that (and the fluid is designed for such use). I don't recall seeing a lot of talk about transmission fluid venting, so it's either uncommon or nobody notices. There is no transmission cooler other than the one already in the truck. Current F150 with 10 speed transmission also doesn't have an additional cooler for trailer tow.

 

[VAMike]

Also probably worth noting that the reason there's a engine coolant heat exchanger built into every 10 speed is actually so it can get the temperature up as quickly as possible when starting out. These things aren't the same as pop's hydramatic and experience with old transmissions doesn't transfer.

 

[jas]

Ok, so per dealership, transmission fluid levels were great, so hopefully @RANGER PRIDE, you were right and there was just a bit too much in there and this self-leveled things. Also so happy to know that 206ºF-215ºF is normal operating temperature. I picked it up yesterday and things are looking good. Let’s hope they stay that way. ?

 

[awd.nv]

Anyone know what the upper end of safe is for temps while towing especially? This weekend towing a 19ft travel trailer (~4200lbs) in the hot 100F southwest I peaked 230F while climbing but other than that one time, I had some minor peaks in the 220F range. Otherwise was usually in the 205-215F range.

Don't want to spend money upgrading cooling unless I actually need it.

Thanks

 

[VAMike]

Anyone know what the upper end of safe is for temps while towing especially? This weekend towing a 19ft travel trailer (~4200lbs) in the hot 100F southwest I peaked 230F while climbing but other than that one time, I had some minor peaks in the 220F range. Otherwise was usually in the 205-215F range.

Don't want to spend money upgrading cooling unless I actually need it.

Thanks

A lot of people who learned to drive on older transmissions freak out over the temperatures on the 10R80. AFAICT the best thing to do is stop watching the temperatures. There are basically zero reports of temperature-related transmission issues, and this transmission has been running for years in other applications (with the same sort of temperatures). You will find people who are determined that they know better than the ford engineers, and cobble together all kinds of wacky aftermarket cooling solutions. Be aware that ford put a lot of effort into getting the temperatures up as fast as possible, and you're more likely to screw the thing up by "fixing" it than by leaving it alone.

The normal operating range, that is driving to church on sunday (as long as that's a long enough drive to warm up), is 206-215. Basically engine coolant temperature--because ford uses the engine coolant to warm up the transmission. Then the coolant flow is shut off and the transmission is on its own. At some higher temperature than that the transmission will use coolant to cool the transmission. People who obsess over transmission temperatures usually report that it'll rise to some temperature and then stabilize or decrease--that's the coolant kicking in. At some other temperature it'll go into limp mode. At a temperature above that, you'll exceed the temperature rating of the fluid. You won't overheat the transmission without noticing.

And remember that the same transmission design with the same lack of an extra transmission cooler is powering the max tow on an f150. You're not towing an f150 max load with your ranger.

 

[Leftcoast]

A lot of people who learned to drive on older transmissions freak out over the temperatures on the 10R80. AFAICT the best thing to do is stop watching the temperatures. There are basically zero reports of temperature-related transmission issues, and this transmission has been running for years in other applications (with the same sort of temperatures). You will find people who are determined that they know better than the ford engineers, and cobble together all kinds of wacky aftermarket cooling solutions. Be aware that ford put a lot of effort into getting the temperatures up as fast as possible, and you're more likely to screw the thing up by "fixing" it than by leaving it alone.

The normal operating range, that is driving to church on sunday (as long as that's a long enough drive to warm up), is 206-215. Basically engine coolant temperature--because ford uses the engine coolant to warm up the transmission. Then the coolant flow is shut off and the transmission is on its own. At some higher temperature than that the transmission will use coolant to cool the transmission. People who obsess over transmission temperatures usually report that it'll rise to some temperature and then stabilize or decrease--that's the coolant kicking in. At some other temperature it'll go into limp mode. At a temperature above that, you'll exceed the temperature rating of the fluid. You won't overheat the transmission without noticing.

And remember that the same transmission design with the same lack of an extra transmission cooler is powering the max tow on an f150. You're not towing an f150 max load with your ranger.

There, I learned something today.

 

[TremorOwner]

Trans was probably overfilled. Been there... caused it.

 

[micl9]

I found this in the Service Manual

​

Transmission fluid should be checked with the vehicle on a level surface and at
normal operating temperature. (Normal operating temperature 96°C (206°F) to
101°C (215°F)).

​

keep in mind the range is for NORMAL not overall. So getting a bit over 220 is probably not surprising​

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