Axle Oil Temperature Warning

[FISHTAIL]

With the higher redline of the Gen III and higher compression/more power, I'm not surprised to hear that. The Gen IIs were borderline in that department, especially if pushed hard to 6500+. Past that rev limit the engine temps climb quickly, so I can believe one being pushed to 7500 would start overheating the oil especially a 5w20.

Except I believe the manual specs 5w-30 for track use. But still.

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[PoppinJ]

Except I believe the manual specs 5w-30 for track use. But still.

The Manual Does indeed state 5w-30 for track use, and switching back to 5w-20 after the event.



Ive heard that the 2015+ axle temp alarm, reduce speed warning triggers at 293. Im almost positive that the 2018 triggers at a lower temp. I didnt pay close enough attention but Im thinking its triggering around 275. All other temps were fine.



At Eagles Canyon Raceway for the May track day temps were around 97 for the afternoon runs. The first early morning session is the only one that didnt trigger the Alarm. All other runs triggered the axle temp alarm after 15-20 min, closer to the 15 min mark most of the time. Super disappointing. Ive heard (but not confirmed) that the car will go into limp mode if the diff temp hits 315?? Anyone know?



Im looking into ways to drop the diff temps, or at least get a full 25 min session before the alarm triggers. Im not looking to tear up the car so I pull off when the alarm triggers at ~275, just sucks to end the session 3 laps early. Im prob going to change the diff fluid to a thicker weight as there seems to be a bit of success with that. Also going to wrap the exhaust around the diff. Ive thought about grabbing the manual trans cooler scoop as that may also direct air towards the diff as well, but the air looks like it would run over the exhaust first which is no good. I just REALLY wish someone would come out with a finned diff cover, similar to the 2014 Shelby 500.

 

[NightmareMoon]

Redline 75w140 gear oil and header wraps around the exhaust where it goes around the diff and I've never had the warning on my 16. Manual trans and traction contol turned off, and the last track day was 95 deg, with short breaks between sessions (45 min)?

 

[Norm Peterson]

I think people having any problems that might involve short cool-down periods or unusually high ambient temperatures should be driving slowly around paddock or on the access roads for a couple of miles or so. Moving air is going to do a better job of removing heat and getting it completely away from the car than just sitting in paddock letting it all soak. Not a bad thing for the brakes, either.


Norm

 

[GTP]

I wrapped my exhaust around the pumpkin, changed to 140W diff oil, and put a temp sticker on the diff. Temp gauge is from Optimum Performance.

 

[DickR]

How does thicker oil reduce axle temps? I thought thicker oil means more heat and maybe more heat tolerance, especially if the oil is otherwise "better".

Thanks.

 

[NightmareMoon]

How does thicker oil reduce axle temps? I thought thicker oil means more heat and maybe more heat tolerance, especially if the oil is otherwise "better".

Thanks.

IIRC, at higher temps the oil viscosity decreases. If it decreases too much it doesn't lubricate well, and that's where you get the extra wear and heat.

Normally (in an engine) yes, lower viscosity oils will flow better and thus cool better, but the same thing applies. Go too low and it doesn't do its primary job.

 

[jbird60]

IIRC, at higher temps the oil viscosity decreases. If it decreases too much it doesn't lubricate well, and that's where you get the extra wear and heat.

Normally (in an engine) yes, lower viscosity oils will flow better and thus cool better, but the same thing applies. Go too low and it doesn't do its primary job.

This :amen:

Getting the right oil weight for a given application is a clever balancing act between heat dissipation at lubrication.

 

[BigBoss5.0]

2nd Track day, had the exhaust that surrounds the diff wrapped. Temps were better longer but still climbed to 175 Celcius. Guess its time to change the fluid...

 

[PoppinJ]

So since the manual specifies 75w 85 on page 298 for the rear diff are there any downsides to using 75w140? Marginal increase in wear and tear during non track temps? Not to big a deal for me during Texas Summers, but something to think about during the winters. Im assuming you guys are leaving it in year round. How many hours of track time do you get on 75w140 before it needs to be changed?


GTP, you said you use Red Line 75w140 Sythetic Gear oil right? This stuff, no friction modifier required?

https://www.amazon.com/Red-Line-75W140-Synthetic-Oil/dp/B001M8USMY

And while Im asking, how often do you guys who track a bit change the tranny gear oil?

 

[GTP]

I used Motorcraft 75w140 that I purchased from another forum member. Bought the 4oz friction modifier from a local dealer.

Hardest part was not using a gear oil pump. Never again.

I haven't changed the oil since. My temp gauge sticker didn't even register on the lowest dot. My local track is easy on cooling and tires. (I'm the guy who doesn't follow every little recommendation about changing fluids. )

However, I will change my brake fluid soon, now at 26k miles.

 

[mcstang18]

First track day with the new '18 GT this morning at Raceway Park of the Midlands in Iowa. I made it through two 20-minute sessions before getting the axle warning about 15 minutes into both the third and fourth sessions.

Downtime was only 20 minutes between sessions because the 85-90° temperatures scared away most people; our run group had only 7 cars so everyone had adequate space to run traffic-free.

I didn't have time to experiment with longer waits between sessions; I only paid for a morning session so I wanted to maximize my time on track. I'll have to be mindful of the overheating potential in the future. I pushed hardest on my early session laps in hopes backing off a little later would keep the warning from appearing and I'd get the full 20 minutes in, but no such luck.

Looks like I should try the 75W140 and see if that helps.

 

[NightmareMoon]

So since the manual specifies 75w 85 on page 298 for the rear diff are there any downsides to using 75w140? Marginal increase in wear and tear during non track temps? Not to big a deal for me during Texas Summers, but something to think about during the winters. Im assuming you guys are leaving it in year round. How many hours of track time do you get on 75w140 before it needs to be changed?


GTP, you said you use Red Line 75w140 Sythetic Gear oil right? This stuff, no friction modifier required?

https://www.amazon.com/Red-Line-75W140-Synthetic-Oil/dp/B001M8USMY

And while Im asking, how often do you guys who track a bit change the tranny gear oil?

IIRC the fiction modifier isn't needed for the 75W140 in a Torsen, and may actually hurt cooling a little. I'm not running it year round and haven't noticed any downsides. Going to change it out before the next track day though since its been in there a while.

 

[Kep4]

Googled 'Torsen Axle Lubricant':

https://torsen.com/lubricant-part-2/

https://torsen.com/tbr-lube-friction-modifier/

https://torsen.com/category/maintenance/

 

[RAM]

There has been a few threads recently regarding 2018 GT 5.0 engine oil concerns, more so total Quarts needed - because some Dealership Service Centers are only refilling with (8) Qts when the 2018 takes a total of (10) Qts.

If he was running into higher oil temps, not saying the above happened to his vehicle, BUT he may want to make sure it has (10) Qts (if a GT) and dipstick is reading full on level ground.

I just had that experience at the Frod dealer service dept. Only 8 quarts stated on my service ticket. 3 differnt techs said they were positive it was only 8 qts. I had them drain the new oil and remove the new filter and start over and it took exactly 10 qts.

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