GT350 Fluid Temps on Track

[Flyboygsxr]

Not to change subjects but has anyone changed their diff fluid yet? What are the recommended intervals of track vs street driving?

 

[OPMustang Tim]

Not to change subjects but has anyone changed their diff fluid yet? What are the recommended intervals of track vs street driving?

Ford says after the first hour and then every 12 hours. Reality change it after the first track day, everything will be well mated by then. If you are going to swap it move up to a 75W-140.

 

[mattlqx]

Ford says after the first hour and then every 12 hours. Reality change it after the first track day, everything will be well mated by then. If you are going to swap it move up to a 75W-140.

That's what I did.

I don't believe I had a DTC for it. It was a few hundred miles afterwards before I could check it. I'll be more prepared next event.

 

[65sohc]

75W-140 is the oil to use on track regardless of Ford's factory fill. I run Miller Oils with no friction modifier. I ran the factory 75W85 and got the overtemp warning in 3 laps and the wrench light warning at 5-6 laps. With Millers 75W90 I got the warning between 4-6 laps and never got the wrench. With Millers 75W140 I have only gotten the overtemp warning twice during 25 minute sessions at Watkins Glen, most times I don't get it at all. I have been putting together factory track pack parts to add a diff cooler to my car, will complete it before next season.
Steve

So with 75W-140 you don't go into limp mode?

 

[Flyboygsxr]

So with 75W-140 you don't go into limp mode?

Are you in a GT350 or a regular GT? Do you have a differential cooler? I ask because the differential on my GT350 has never gotten anywhere near overheating and I've done 30 minute sessions in 85-90 degree ambient temperatures.

Adam

 

[OPMustang Tim]

I wonder if leaving the nannies on could increase temps like they did in the Boss?

S550 only holds about 1.5L of fluid, 3.73 cars spin the pinion fast so a lot of heat is generated. 140 holds up pretty well during a session. A cooler is a good idea which we are still working on for the GT's.

 

[OPMustang Tim]

Are you in a GT350 or a regular GT? Do you have a differential cooler? I ask because the differential on my GT350 has never gotten anywhere near overheating and I've done 30 minute sessions in 85-90 degree ambient temperatures.

Adam

Adam, with a cooler you will not see the high temps, if you track the car 140 is a much better option if you are changing it.

 

[VoodooBoss]

Adam, with a cooler you will not see the high temps, if you track the car 140 is a much better option if you are changing it.

I saw 257+ on mine with a cooler and stock fluid. What's high? See the first post in this thread.

 

[OPMustang Tim]

I saw 257+ on mine with a cooler and stock fluid. What's high? See the first post in this thread.

293F is high. Not sure if rear diff causes limp mode on Shelby's, it just gives a warning and code on the GT's. The Shelby coolers rely on airflow under the car so depending on track temp, ambient and speeds even with a cooler it will get hot. The air across the cooler is everything under the car (which is hot) so the delta gets smaller. Maybe the solution woud be to add an additional cooler with fan in series so you gain fluid capacity and liquid to air surface. If you operated the pump with an additional cooler/fan between sessions you would be able to lower starting temps closer to ambient.

If you see over 293F it's a good idea to change the fluid before the next event. The heavy viscosity (140) gives you that extra cushion operating at higher temps.

 

[65sohc]

Are you in a GT350 or a regular GT? Do you have a differential cooler? I ask because the differential on my GT350 has never gotten anywhere near overheating and I've done 30 minute sessions in 85-90 degree ambient temperatures.

Adam

Just updated my sig.

 

[65sohc]

Just updated my sig.

So is the thinking that it is the differential oil temp rather than trans that is causing the limp mode on the tech pack GT350's?

 

[VoodooBoss]

Most of the GT350 owners posting in this thread have a car with the stock diff and trans coolers. Matt originally had a 2016 tech and sold it and bought a 2017 tech which has the coolers. My trans stays really cool but my diff is getting hot.

 

[moto]

Here is mine from today after clearing from a very high speed run at Autoclub speedway. The axle was actually up to about 260 but cooled off quickly as I cleared. OAT about 82deg.



Sent from my iPhone using Tapatalk

 

[VoodooBoss]

You were seeing similar diff temps to mine. Both Fontana and Thunder Hill are high speed tracks so I'm sure that has a big impact on the temps. I sure wish the diff ran as cool as the trans.

 

[rgator]

Hi everyone, I am new to the forum, and have some insight from my experience with diff temperature at the track. I also have been experiencing 270+ temps. I had Ford check my pump and they said all was good, but what I found out is that forcing the pump on with forscan or other program the pump turns on, but it will not turn on by itself when the temp is high as I found out when I put a 500ohm resistor in the temp sensor plug which made the gauge go over 300F, I did not get a DTC code set nor did the pump turn on. I went back to Ford who claimed my Lund tune wiped out all the ford programming for the diff pump and they will not look at my car. So I am going to put a rad fan controller to turn the pump on when it reaches 190 and I will see if that controls the temp. I am not sure if the stock software cycles the pump on and off or keeps the pump running until it cools down. I will post back in the spring after my first track day to let you know how it worked but it has to work better than no pump running at all. I still suspect that the programming was missing from Ford to begin with as my car is an early 16. If anyone has any insight to this that would be appreciated.

 

[CSL]

Have Lund check your tune to confirm the tune isn’t the issue, and if it is have them give you a tune revision. I’d start there first. It’s common to have the diff temps climb much higher than trans temps when tracking the car.

 

[JAJ]

Have you checked with Lund?

The car rolled out of the factory with the programming installed, and it's still there if Forescan and Ford IDS can control the pump. It's unlikely that Lund actually killed the software that runs the pump - if they did it wouldn't work at all. It's more likely that they turned off an option switch that stops the ECU from generating certain diagnostic trouble codes. Without DTC's, the Ford techs are flying blind and they don't know what's wrong or where to start looking, so they can't fix it. I suspect (and it's just a guess, but an educated one) that if you reflash to stock, you'll unflip the switch and at that point you'll be able to get a DTC for the pump that will tell you what the problem is.

Where are you? Canada's a big place.

 

[rgator]

Have you checked with Lund?

The car rolled out of the factory with the programming installed, and it's still there if Forescan and Ford IDS can control the pump. It's unlikely that Lund actually killed the software that runs the pump - if they did it wouldn't work at all. It's more likely that they turned off an option switch that stops the ECU from generating certain diagnostic trouble codes. Without DTC's, the Ford techs are flying blind and they don't know what's wrong or where to start looking, so they can't fix it. I suspect (and it's just a guess, but an educated one) that if you reflash to stock, you'll unflip the switch and at that point you'll be able to get a DTC for the pump that will tell you what the problem is.

Where are you? Canada's a big place.

I am just outside Toronto Ontario. When this was going on I did talk to Lund and they say their programming does not have anything to do with software associated with the diff, I later put the stock tune back in and received the same results no DTC triggered and the pump not turning from the temp sensor reading. I am saying all this because other people are reporting high diff temps and some reporting what I would say normal temps 190F, so with my experience I believe there is something wrong in the programming. I have gone to 2 different dealers who after cycling the pump keeps telling me all is good, I called Ford Canada who basically told me once you have purchased the car you are at the mercy of the dealer to help you or not. Since no DTC are triggered there is no fault for the dealer to find. I am at the point that a simple splice into the harness with a fan controller and it will be automatic again. I am just not sure if the pump should run continuous after it reaches temp or is it supposed to cycle on/off until it reaches the set point as the cooler is small and too much flow won't help cool the oil.

 

[JAJ]

OK, well, it was a great theory. So, do you know if the pump is actually pumping anything? Did your friendly dealer do any kind of volume testing? The ECU runs the pump and will throw codes for lots of things, but whether the pump is actually moving anything is probably not one of them. It could be a defective pump that passes the self-test from the ECU, that spins and sounds like it's working but has an impeller that isn't moving anything.

 

[rgator]

OK, well, it was a great theory. So, do you know if the pump is actually pumping anything? Did your friendly dealer do any kind of volume testing? The ECU runs the pump and will throw codes for lots of things, but whether the pump is actually moving anything is probably not one of them. It could be a defective pump that passes the self-test from the ECU, that spins and sounds like it's working but has an impeller that isn't moving anything.

The pump does pump when I change the diff fluid and I use forscan to activate it you can hear it change pitch as the fluid starts to go thru it plus when draining the diff it pumps the bal. of fluid out. It won't turn on when it is supposed to when it gets hot. Because the dealer finds no codes and can cycle the pump as far as they are concerned all is good, and they are telling me I shouldn't track my car as it voids the warranty, so much for advertising and promoting a track ready car.