Sponsored

"Rear Axle Differential Temp Increased, Decrease Speed" warning

higdominator

Well-Known Member
Joined
Aug 6, 2015
Threads
24
Messages
1,552
Reaction score
383
Location
Central Oklahoma
Vehicle(s)
2016 GT PPP
I have a 3.15 Al diff sitting in the garage waiting for me to stop being lazy. I just can't decide if I want to keep the 3.73's or go with a 3.55 gear set. I think it would be just fine for road course use (stock aluminum).
Sponsored

 

ForTehNguyen

Well-Known Member
Joined
Apr 23, 2015
Threads
17
Messages
2,248
Reaction score
693
Location
Houston, Texas
Vehicle(s)
15 GT
iron doesnt shed heat as well as aluminum, its harder to cool
 

Jeffy_2010

Well-Known Member
Joined
Apr 26, 2015
Threads
58
Messages
1,167
Reaction score
205
Location
Missouri
First Name
Taylor
Vehicle(s)
2015 gt 6-speed/ performance pack Oxford white
Alright guys just read through the whole thread and in my got a couple questions, did we ever come to a conclusion what weight fluid is best to run? Is there any way for the 2015 guys to monitor temps? And when will said oil coolers be ready for purchase? Lol
 

ANGST

Well-Known Member
Joined
Dec 3, 2014
Threads
67
Messages
600
Reaction score
201
Location
Herndon VA
First Name
Steve
Vehicle(s)
18 Cayman GTS, 15 Explorer Sport , 09 Honda Fit
Alright guys just read through the whole thread and in my got a couple questions, did we ever come to a conclusion what weight fluid is best to run? Is there any way for the 2015 guys to monitor temps? And when will said oil coolers be ready for purchase? Lol
75W-90 or 75W-140

I'd give [MENTION=22413]Optimum Performance[/MENTION] a try with this kit :

http://www.opmustang.com/store/p2/B...6_FORD_MUSTANG_REAR_AXLE_LUBE_CHANGE_KIT.html

They also have stickers to monitor the diff temp , but it would not be easy to set it up like the 16+
 

NvrFinished

Well-Known Member
Joined
Sep 11, 2015
Threads
22
Messages
1,035
Reaction score
504
Location
So Cal
Vehicle(s)
2016 DIB GTPP
My first HPDE I ran the 75w-90 and got the warning light. I changed to the 75w-140 from Optimum Performance for my second and third HPDE and didn't get the warning light. I believe it's the better fluid choice, but it's not the answer to our problems.
 

Sponsored

wmfateam

Well-Known Member
Joined
May 4, 2017
Threads
11
Messages
318
Reaction score
141
Location
Arizona
Website
www.facebook.com
First Name
Whitey
Vehicle(s)
2017 LB GT PP
Vehicle Showcase
1

Jeffy_2010

Well-Known Member
Joined
Apr 26, 2015
Threads
58
Messages
1,167
Reaction score
205
Location
Missouri
First Name
Taylor
Vehicle(s)
2015 gt 6-speed/ performance pack Oxford white
Has anyone installed a traditional diff temp sensor and gauge? Requires drilling into the diff cover and welding in a bung of course
 

Gatorac

Chin Tack Days Event Mgr
Joined
Sep 10, 2015
Threads
7
Messages
248
Reaction score
163
Location
Bradenton FL
First Name
Jim
Vehicle(s)
2016 Premium GTPP Triple Yellow
Has anyone installed a traditional diff temp sensor and gauge? Requires drilling into the diff cover and welding in a bung of course
Most temp sensors are 1/8" NPT. Drill and tap is all you need. Or an adapter for the drain hole.
 

pstoppani

Well-Known Member
Joined
Aug 2, 2016
Threads
1
Messages
60
Reaction score
18
Location
Redmond, WA
Vehicle(s)
2017 GT PP
I was under the impression that the overheating diff didn't cause a limp mode and that was my experience until this week when the car refused to go above 6000 RPM ... maybe it was something else? I got the overheat warning along with time to change oil warning. After 15 minutes in 80F ambient, rev limiter kicked in at 6000!
Figured out the limp mode; it’s from engine oil temperature getting too high, as in getting to the yellow zone on the temp gauge. Pacific Raceways has a very long front straight and if I stay in 5th, close to redline, it gets too hot. Short shifting to sixth fixed it. The car runs very close to the yellow zone...

Also, put in the diff fluid from Optimum Perf greatly reduced the diff over temp warning; only saw it once six sessions. Maybe short shifting helped.

Ambient temp was 75F. Clearly the car needs better cooling for engine and diff.
 
Last edited:

Sponsored

Kahboom

Kahboom
Joined
Nov 28, 2014
Threads
26
Messages
1,206
Reaction score
184
Location
Cathedral City, CA
Vehicle(s)
2015 Mustang GTPP, Recaros/2014 Explorer Sport 4X4
The Boss 302 and the Track Pack cars for the previous generation it was recommended using 5w50 for track days or autocrossing the 2015+ GT performance pack is no different it is still recommended using 5w50 for autocross or track days. It also wouldn't be a bad idea to run 170 degree thermostat and have your fans tune for it even if you are just stock.
 

EXP Jawa

Well-Known Member
Joined
Jun 9, 2014
Threads
3
Messages
1,011
Reaction score
205
Location
Rochester, NY
Website
www.torsen.com
First Name
Rick
Vehicle(s)
1999 Cobra Convertible, Electric Green
Alright guys just read through the whole thread and in my got a couple questions, did we ever come to a conclusion what weight fluid is best to run? Is there any way for the 2015 guys to monitor temps? And when will said oil coolers be ready for purchase? Lol
75W-90 or 75W-140

I'd give @Optimum Performance a try with this kit :

http://www.opmustang.com/store/p2/B...6_FORD_MUSTANG_REAR_AXLE_LUBE_CHANGE_KIT.html

They also have stickers to monitor the diff temp , but it would not be easy to set it up like the 16+
FWIW, at least for the GT350 guys - a conversation I had a few weeks back with a colleague at Ford Performance suggested that cars with the OEM axle cooler needed the factory 75W85. He said the cooler didn't flow well enough for 75W140. Since this came from someone involved with testing the FP350S, I suspect he knew what he was talking about.
 

ANGST

Well-Known Member
Joined
Dec 3, 2014
Threads
67
Messages
600
Reaction score
201
Location
Herndon VA
First Name
Steve
Vehicle(s)
18 Cayman GTS, 15 Explorer Sport , 09 Honda Fit
FWIW, at least for the GT350 guys - a conversation I had a few weeks back with a colleague at Ford Performance suggested that cars with the OEM axle cooler needed the factory 75W85. He said the cooler didn't flow well enough for 75W140. Since this came from someone involved with testing the FP350S, I suspect he knew what he was talking about.
We are talking about regular GTs , they have no axle coolers
 

wildcatgoal

@sirboom_photography
Joined
Feb 8, 2016
Threads
76
Messages
6,589
Reaction score
2,500
Location
USA
Vehicle(s)
TBD
FWIW, I doubt a finned differential cover is going to do much given we aren't talking about a great deal of air flowing under this car (as compared to a pickup truck, where a finned differential cover makes a lot of sense, or older Mustangs that were higher off the ground with a differential lodged between the axle smack within in the airflow vs. tucked up into an IRS subframe). I mean fins are more surface area and help dissipate more heat for the same airflow and I'm sure it'll stave off a diff warning a wee bit longer but I'm not convinced it's a worthwhile spend of limited dollars. I look into what I know is working -- Steeda's #20 race car uses an in-house-assembled differential cooler and OEM weight (75W90) fluid, the parts list for which they've published on this forum somewhere. This was their approach that stopped this issue even for endurance races. Once a clean, consumer kit is available from Optimum Performance or Steeda, I'll buy one, because after I got relatively comfortable with that high speed course, I got the m'fing diff temp warning on maybe the 3rd to last lap of 20-min sessions if I was lucky enough to barrel through traffic and have some free space. That said, I use BG 75W140 fluid bought from Optimum Performance. With the stock fluid, I used to get the diff temp warning sometimes at AMP (even my first time there and on my very first track day in the car), but now I never do. I never got it with the 75W90 BG fluid I used prior to the 140 fluid at AMP, but I decided to go to 140 after concluding with my own research that it seems Torsen recommends 140 if you buy a differential directly from them and says "use what the manufacturer recommends" if you don't. The 140 weight also reduced a lot of whine so much that even with my aluminum differential inserts and through-bolted differential mounting, I don't get much race-car noise. The driveline, with 140 fluid, also feels a little "plushier" but I probably wouldn't notice that if I didn't have all the IRS and diff stiffening stuff on my car.
Sponsored

 
Last edited:
 




Top