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

Status
Not open for further replies.
I think changing the fluid often is just going to be a bandage, honestly. I kinda think these things are going into like a thermal runaway situation where the heat is
1. Lowering the viscosity of the oil to the point the gears are breaking the flim and increasing the friction and heat input into it.
2. Expanding everything, which increases the preload on the bearings, which increases friction further.

Agree Redline is probably the best product.
 
Originally Posted By: Colt45ws
I think changing the fluid often is just going to be a bandage, honestly. I kinda think these things are going into like a thermal runaway situation where the heat is
1. Lowering the viscosity of the oil to the point the gears are breaking the flim and increasing the friction and heat input into it.
2. Expanding everything, which increases the preload on the bearings, which increases friction further.

Agree Redline is probably the best product.



Possible, but the question remains WHY? Even with the small fluid sump, these things are not *supposed* to be loaded until front wheel slip occurs. Makes me wonder if there's a lot of drag in the rear decoupling mechanism or something. I have a hard time believing that its all due to radiant heat from the catcon too, although that could be a lot of it.
 
No, they are pushing power though it much more than than just wheel slip. I watched a video on YT of a Explorer Sport taking off with a fancy display showing the power disposition.
He stomped the gas from a standstill and like 80% of the power went to the rear and slowly drifted back to the front as it sped up until it was about 50/50.
Although that was WOT. But it didn't go, "OH wheelslip is over I can pull it all back to the front now." There was at least like 40% going back there even at the end of the pull.
Can anyone here with that display capability confirm how much of the time power is going to the rear in less aggressive situations? Like cruise?
 
The PTU cooler on the Police Interceptor and SHO Perf Pkg reduces the fluid temp by 75F according to an article from Motor Trend. The coolant is routed to a cooler integrated into the passenger side casing of the PTU. There's a drainplug on those PTUs, but not on the regular PTUs.
 
That's massive cooling ......
and really value for money ..... and appears to me a 'must have' in this application.
blush.gif
 
Originally Posted By: metroplex
The PTU cooler on the Police Interceptor and SHO Perf Pkg reduces the fluid temp by 75F according to an article from Motor Trend. The coolant is routed to a cooler integrated into the passenger side casing of the PTU. There's a drainplug on those PTUs, but not on the regular PTUs.


If you look back a page, that was what I posted pictures of. The PTU covered in fluid had that cooler and still failed.
 
Originally Posted By: bdcardinal
Originally Posted By: metroplex
The PTU cooler on the Police Interceptor and SHO Perf Pkg reduces the fluid temp by 75F according to an article from Motor Trend. The coolant is routed to a cooler integrated into the passenger side casing of the PTU. There's a drainplug on those PTUs, but not on the regular PTUs.


If you look back a page, that was what I posted pictures of. The PTU covered in fluid had that cooler and still failed.


Yep! Which is the oddest thing. If the flash point on Motorcraft 75W-140 is just shy of 400F and the PTU cooler sheds 75F of heat, then the PTU must be reaching somewhere near 500F?
 
At least on the Pursuit Utility or whatever they want us to call the police Explorers, they have one of the manicats rights next to it cooking it.
 
You have to remember an increase in speed will increase the heating. So if they are running them as hard as you think they would, then how much higher is the temperature getting than someone tooling around? Obviously enough to negate that cooler.

Like we were talking about, they should all be getting the integrated cooler, and the police cars (and SHOs) should be getting the $3000 heavy duty cooling option that Im super super curious to get pictures of and see what it actually is.

Also, it doesn't have to be that hot. If it was hitting the fire point, you would know it. I think if it was in the 300-400 range long enough it would turn to sludge like that.
Thats where my money is if someone installed a temp sensor in one.
 
Last edited:
Depending on the quality of oil seal materials in use, the oil seals would've hardened and failed (and require immediate replacement due to excessive oil leaks) at 250-350*F range
......... well below lubricants typical flash point and fire point.
blush.gif


Edit:Flash point
 
Last edited:
Just found this thread after posting something about my '14 Explorer Sport.

Having a problem finding a PTU filling location. Has a drain plug, no fill plug and the top sensor is covered by a metal shield. Have heard of people using the vent hole but not sure where that is located or how to get at it...
 
I saw a YouTube video review of the 2013 SHO done by Autoweek and they showed a temperature scan of the PTU with and without cooler. The integrated PTU cooler reduces the temp by 16%, with the non-cooled PTU maxing at 284F while the cooled PTU maxes out at 266F. I wouldn't say this is a huge difference at all.

The Police Interceptors have the PTU as an option, 52B, and only on the 3.5L EcoBoost models. Ford says it is recommended for EVOC training and extended track usage.
 
Originally Posted By: buck91
Just found this thread after posting something about my '14 Explorer Sport.

Having a problem finding a PTU filling location. Has a drain plug, no fill plug and the top sensor is covered by a metal shield. Have heard of people using the vent hole but not sure where that is located or how to get at it...


With the engine reasonably cool ya gotta reach above the PTU from behind. Its there.
 
Yes, the exhaust and catalytic converters are basically sitting right below the PTU case. On the Explorers with towing packages, there is a duct that directs air onto the PTU case from the front bumper (you will see some Explorers with a cut-out on the lower air dam on the passenger side). On the Taurus/SHO, the belly pan has a shape that directs air flow onto the PTU area. None of these are real solutions though but Ford obviously knows about these problems.
 
No, 190 at KV@40C 365 cSt isn't too thick here .....
for a quality HD 85W140 has an equally strong KV@40C of 333 cSt.

Originally Posted by metroplex
I saw a YouTube video review of the 2013 SHO done by Autoweek and they showed a temperature scan of the PTU with and without cooler. The integrated PTU cooler reduces the temp by 16%, with the non-cooled PTU maxing at 284F while the cooled PTU maxes out at 266F. I wouldn't say this is a huge difference at all.

These temperature zones should be avoided at all cost (never mind what the OEM says) , other than a high capacity cooler a higher KV@40C gear oil in Ams SAE 190/250 would be my selection.
 
Last edited:
On my Explorer Sport … I wrapped the exhaust with titanium header tape … That shuts down most of the heat …
 
Status
Not open for further replies.

Similar threads

S
2021 Ford Edge AWD TU Drain and Fill
Replies
6
Views
1K
SureshR
T
Ford PTU, rearend, transmission flush and change,
2
Replies
31
Views
3K
thejudges69
N
Substitute Motul Gear 300 75W-90 for BMW G1 75W85?
Replies
1
Views
639
oldhp
ensoniqman
Mopar 75w-140
2
Replies
26
Views
4K
benjy
havingabadhairday
2017 Ford Explorer XLT 3.5 Duratec PTU mods.
Replies
4
Views
3K
havingabadhairday
Back
Top