Power Transfer Unit (PTU)- 75W-140 recommendations

[SanMan]

Sorry for the stupid question, but Redline sells 2 different 75-140 gear oils,

1. 75W140NS GL-5: https://www.amazon.com/Red-Line-571...;qid=1559446842&s=gateway&sr=8-2

2. 75W140: https://www.amazon.com/dp/B0045FCE5U/ref=psdc_15719351_t1_B0006HKN6S

Which one is correct for the PTU?

 

[Whimsey]

Originally Posted by SanMan
Sorry for the stupid question, but Redline sells 2 different 75-140 gear oils,

1. 75W140NS GL-5: https://www.amazon.com/Red-Line-571...;qid=1559446842&s=gateway&sr=8-2

2. 75W140: https://www.amazon.com/dp/B0045FCE5U/ref=psdc_15719351_t1_B0006HKN6S

Which one is correct for the PTU?


The 75W-140 is the correct one to use. The 75W-140NS GL-5 is meant for manual transmissions and transaxles.

Whimsey

 

[DoubleWasp]

I've mentioned this before, but there is an older and wider situation of a small capacity power transfer unit: Marine outdrives

The Mercruiser ones in particular are known to operate at around 280°F on the upper end of the gearcase because it is out of the water when at speed.

50 hours of running this temperature is enough to turn new gear oil into black soup in these drives.

People use a product called a drive shower that directs water to shower the upper gearcase. Lowers temps by about 40°. That's with water at below ambient temperature.

I wouldn't expect directing hot engine coolant to the Ford PTU to do a better job, so I'm not surprised the PTU cooler isn't doing much at all.

 

[SanMan]

Originally Posted by Whimsey
Originally Posted by SanMan
Sorry for the stupid question, but Redline sells 2 different 75-140 gear oils,

1. 75W140NS GL-5: https://www.amazon.com/Red-Line-571...;qid=1559446842&s=gateway&sr=8-2

2. 75W140: https://www.amazon.com/dp/B0045FCE5U/ref=psdc_15719351_t1_B0006HKN6S

Which one is correct for the PTU?


The 75W-140 is the correct one to use. The 75W-140NS GL-5 is meant for manual transmissions and transaxles.

Whimsey


Ah, thank you!

 

[4WD]

My Explorer PTU was right above both exhaust tubes … so in stop & go traffic they don't get to cool like they should … and that cooling duct I had was just road speed air induced … (scoop intake)

I did wrap the exhaust with header tape … cheap and easy …

 

[metroplex]

I found out that there is a datalogging parameter available for the Fusion Sport for the transfer case fluid temperature using FORScan. So I logged it after a normal commute home.

Ambient 70F
Transmission Fluid Temp was about 160F and rising
Engine Coolant Temperature was about 200F and rising
Transfer Case Fluid Temp was 145F

I'm fairly positive that the Fusion Sport's PTU is the same as the Escape and 2.3L EcoBoost Explorer PTU, while the 3.5L/V6 Explorer and Edge PTUs are the ones with the overheating issue. I don't see how a transfer case fluid temperature of 145F is going to overheat in 30k miles just with normal driving.

 

[bdcardinal]

I had the service department do the oil change on my mom's Fusion yesterday along with new tires, Michelin MXM4. While it was in the air I had the tech do a drain and fill on the PTU using Amsoil 75W140. The car had just over 40,577miles and the fluid looked not ideal, but not as bad as some of the Explorer Police Interceptor PTUs.

 

[4WD]

Don't know what temps it reaches on the earlier FWD>>AWD ecoboost 3.5L's … but a half quart is not enough fluid change capacity.
The LEO's mechanic on the internet says he gets around 14 oz out before he "glugs" that amount back in via an air vent hose.

 

[metroplex]

Interesting... Since the Fusion Sport's PTU has drain and fill plugs, I often wondered about installing some kind of gear oil pump and external cooler/reservoir... So that I could drain the system, and remote fill it from the engine compartment while adding extra fluid capacity and maybe run another heat exchanger.