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Navigator Tow Vehicle Transmission Cooling

Indycars

Well-Known Member
I've already added a cooler with 2 fans, but it doesn't seem to be enough when pulling
an 18 foot v-nose enclosed trailer on hills with an ambient temp over 90°F. I've seen temps
reaching just over 205°F and I'm shooting for a max of 175°F.

Below is what I have now ......

FP01_DeraleCooler15840_01249.jpg

FP04_CoolerAndFilter_01276.jpg
The cooler is mounted under the passenger side rear seat with a remote filter. I also
added a temperature switch to turn the fans on automatically, a temp gauge for the
pan and a drain plug to the trans pan.

FP13_TransTempGaugeMounting_01397.jpg

FP14_WiringUnderHood_01442.jpg
Flushed 12 quarts of fluid (Big Thanks to ORF for helping!!!) and now I'm adding a Derale 40 row stacked plate cooler in front of the radiator. This all happened around September 2019.

For the full story about changing 12 quarts of fluid, adding temp gauge and the wiring involved use the link below ......

Trans Cooler Install On Lincoln Navigator | Grumpys Performance Garage

This is not without it own challenges. Getting into the nose of 2008 Navigator is easy, the
problem comes after that. I'm trying to use the OEM cooler while also going thru the radiator
to help warm the fluid in the winter. The a Derale thermostat will direct the fluid around the
cooler until the fluid reaches 180°F. There are rubber hoses connecting to the radiator and
the lines coming from the trans goes thru rubber, I would like to replace all rubber hoses.

This is where I'm headed ......

FP01_FluidLineRouting_02828.jpg
.
 
Do you leave the car in D when you go up these hills?

Got to remember that the S/ware for the trans is written to take into account the weight and power of the car ONLY. Once you add extra weight like a trailer you are changing the parameters for the way the trans should work.

The car still 'thinks' its only got its self to worry about and the pressures, shift points etc are still set to that, not the car plus all the extra weight. We get this a LOT with Range Rovers that tow horse boxes etc. Trans build after 60k and up....

A lot of modern cars with a FACTORY tow bar fitted, changes the mapping of the whole vehicle when a trailer is plugged in. This changes the map for the trans (to account for the extra weigh.) the suspension, the engine and other relevant things.

If you think about it, when pulling a trailer the car (and trans) is put under stress as it is still mapped for a car only. Some cars state in their instructions, to drive in manual shift when towing a trailer as this 'ups' the pressure and delays the lock up. Modern trans will go into lock up in second gear and up to save on emissions and fuel.

I would drive the rig in manual when not cruising along under low throttle. This way you change down manually to reduce the stress on your car, as you would in a stick shift. At the moment its like a stick shift that is in top but needs to go down to 4th or even 3rd.

As always JMHO.
G
 
Does it still get that hot if you drive it in d instead of od? I don’t like to tow anything in od, especially on hills or low speed. It puts a lot of stress on the converter. Imho.
 
A lot of modern cars with a FACTORY tow bar fitted, changes the mapping of the whole vehicle when a trailer is plugged in. This changes the map for the trans (to account for the extra weigh.) the suspension, the engine and other relevant things.
It has a tow package, but I don't find anything in the User's Manual or the Shop Manual that talks about when you plug in a trailer harness.

Some cars state in their instructions, to drive in manual shift when towing a trailer as this 'ups' the pressure and delays the lock up.
Again I have looked thru both manuals and don't find this kind of info.

From the User's Manual - Driving with a 6–speed automatic transmission
This vehicle is equipped with an Adaptive Transmission Shift Strategy. The Adaptive Transmission
Shift Strategy offers the optimal transmission operation and shift quality. When the engine is turned
off, the shift data which includes the adaptive information will be stored automatically in the
Transmission Control Module (TCM).


I did find that pressing this button will keep the trans from going into overdrive. That would mean
to me that 5th & 6th gear would be locked out since they have a ratio of less than 1 : 1 .

Use when driving conditions cause excessive shifting from O/D to other gears. Examples: city traffic,
hilly terrain, heavy loads, trailer towing and when engine braking is required.


upload_2021-8-13_16-30-18.png
.
 
Does it still get that hot if you drive it in d instead of od? I don’t like to tow anything in od, especially on hills or low speed.
No I have not tried using 4th gear. My choices are Drive, 3rd, 2nd and 1st, so I can't manually drive
in 4th or 5th. I'm usually towing at 70 mph and the trans seems to select an appropriate gear. It will
downshift 3 gears when needed to maintain 70 mph, the rpm will be about 4300 rpm before it shifts up.

First Gear 4.17
Second Gear 2.34
Third Gear 1.52
Fourth Gear 1.14
Fifth Gear .87
Sixth Gear .69

Rear Axle Ratio: 3.73
 
Even so the adaptive system is still based on the weight and needs of just the car. Skip shifts are common these days. Which trans is it?
 
No I have not tried using 4th gear. My choices are Drive, 3rd, 2nd and 1st, so I can't manually drive
in 4th or 5th. I'm usually towing at 70 mph and the trans seems to select an appropriate gear. It will
downshift 3 gears when needed to maintain 70 mph, the rpm will be about 4300 rpm before it shifts up.

First Gear 4.17
Second Gear 2.34
Third Gear 1.52
Fourth Gear 1.14
Fifth Gear .87
Sixth Gear .69

Rear Axle Ratio: 3.73
I’m not familiar with your particular transmission. I wish that I could offer more wisdom specific to it. You are right to be concerned with the temperature. Does the operation manual recommend to do anything special to tow with it? A lot of vehicles have a tow/haul mode, which changes shift points and delays or avoids converter lock up or od. Maybe there’s a programming update that would help. Best of luck figuring it out, I’m sure you will.
 
Even so the adaptive system is still based on the weight and needs of just the car.
Here is some more info, very long but I have highlighted anything to do with towing. I don't know where the info came from, but looks like this person did a copy and paste.

Zf6hp26 Six Speed Autmatic Transmission - Australian Ford Forums

ZF 6HP26 six-speed automatic

The six-speed automatic is a compact and lightweight, high efficiency, high torque capacity
transmission with a low first gear, higher top gear and smaller, more graduated steps between
each gear.

“With a larger spread of ratios, the six-speed transmission offers real-world benefits in the
traditionally divergent areas of performance and fuel consumption,” Calibration Supervisor
Tim Postgate said. “The low first gear greatly improves launch feel, while the larger and tighter spread of ratios
delivers livelier performance, especially at wide open throttle, along with the added benefits
of smoother shift quality and reduced fuel consumption.
“Gear shifts between the top few gears are often
imperceptible, while the smaller steps between 3rd, 4th, 5th and
6th also ensure less ‘busyness’ within the transmission as it
determines the right gear.
“The end result of the transmission being in the right gear at
the right time is both an improvement in vehicle performance
and a reduction in fuel consumption.”
Improved transmission cooling capability in the six-speed
auto, by virtue of a heat exchanger, ensures rapid warm-up of
the transmission fluid and a more stable operating
temperature.

As well as contributing to a reduction in fuel consumption, the improved cooling also enables
the maximum towing capacity to be utilised without requiring additional transmission
coolers.

Gear train

The six-speed automatic transmission is based on the Lepelletier gear set, which is
constructed by connecting a planetary gear to a Ravigneaux gear – a double planetary gear set
commonly used in four-speed automatic transmissions.

The sun of the planetary gear is connected to the housing and cannot rotate, while the carrier
of the planetary gear is connected by clutches to the large and small sun wheels of the
Ravigneaux gear.

The input shaft is always connected to the ring of the planetary gear and can be
simultaneously connected to the carrier of the Ravigneaux gear using a separate clutch.
The output, or driven, shaft is connected to the ring of the Ravigneaux gear.
Hardware changes that have been made to the six-speed automatic transmission to suit Falcon
and Territory include:

· Unique transmission main case
· Unique torque converter
· New transmission cross member attachment compatible with both ZF six-speed and ION four-speed automatics
· Transfer case compatibility for Territory AWD application
· Unique output/driveshaft flange
Ford has engineered two versions of the six-speed automatic transmission – a standard
version with a torque capacity of 450 Newton metres and a performance version with a
torque capacity of 600Nm.

The performance version features upgraded clutches, with extra plates in the clutch packs, to
increase the torque capacity for use with higher torque output engines. Falcon, Fairlane and
Territory models using the Barra 190 engine will be fitted with the standard version, while
Falcon and Fairlane models using either the Barra 230, Barra 245T or Boss 260 powerplants
will be fitted with the higher torque capacity performance version.

Software and calibration

“The ZF transmission is able to tailor its responses to individual driving styles courtesy of a
number of software functions and Driver Recognition features, all designed to deliver
increased transmission functionality and performance, and a refined shift quality,” Postgate
said.

The Sequential Sports Shift feature introduced on BA Falcon continues as a key element of
the new six-speed automatic transmission, offering the same style of adaptive and
performance automatic modes as well as total manual control through sequential manual
shifting.

Torque converter clutch lock-up is available in all six forward gears, not just in the top two
overdrive gears. When towing heavy loads at low speeds, such as in city driving or through
hilly terrain,converter clutch lock-up in all gears assists with better transmission cooling and
reduced fuel consumption.

Electronic control of all gearshifts in the six-speed automatic transmission is via clutches
rather than bands, delivering a more direct and refined shift quality.
The internal Transmission Control Module (TCM), which is mounted on the hydraulic
control valve assembly, or mechatronics unit, has been matched to the transmission's valve
body.

The TCM and the valve body are an exact matched pair, with the TCM being calibrated to the
specific valve body during assembly, which ensures accuracy of operation and a more refined
shift quality. Calibration features of the six-speed automatic transmission include:

· Grade Control Logic (Automatic modes)
When driving downhill, with sufficient brake pedal pressure, the transmission will
downshift to provide increased engine braking.
Introduced with the four-speed automatic on Territory, Grade Control Logic operates
in an even more refined and subtle manner with the six-speed automatic transmission,
as the gap between the gear ratios is smaller and the execution of gear changes is
smoother.

· Upshift prevention at zero throttle (Automatic modes)
When coasting downhill from rest, this feature inhibits upshifts beyond 2nd gear with
zero throttle pedal input, to prevent a ‘running away’ feeling.

· Emergency downshift (Manual mode)
When in manual mode, if the throttle pedal is pushed through the detent to activate the
kickdown switch, the transmission will downshift to a lower gear (depending on
vehicle speed) to provide acceleration in an emergency situation. The transmission
will then revert to full manual control, remaining in the kickdown gear and requiring
the driver to input for upshift.

Transient rpm limit

The transient rpm limit allows the engine to momentarily exceed the prescribed rev limit
during upshifting. This enables wide open throttle upshifting of gears to be scheduled at an
engine speed closer to the rev limiter than would otherwise be possible.
The transient rpm feature allows the engine to exceed 6000 rpm – up to 6250 rpm – while the
transmission is completing the gear change, thereby taking full advantage of the high rpm
performance of Barra 190 and 245T engines.

Driver Recognition

A host of advanced features are accessible to the driver as part of the Driver Recognition
software with the six-speed automatic transmission.
“Driver Recognition matches transmission performance to the current driving style by
considering acceleration and deceleration rates, brake and throttle applications, and cornering
speed, to ensure the vehicle is in the right gear at the right time without undesired gear
shifts,” Postgate said.

“The transmission ‘learns’ the driver's style and assigns a theoretical count system to certain
driving scenarios to determine the activation point of particular features.”
The count system extends from a “base” fuel economy bias (0 counts), through stages such as
“sporty” driver (100 counts), up to “enthusiast” (200 counts).
The transmission software recognises various performance-based actions, such as rapid
acceleration / pullaways, enthusiastic cornering, pushing the accelerator pedal through the
detent and moving the shift lever into performance mode, and increases the number of counts
accordingly.

By moving the shift lever across from adaptive to performance mode, the driver recognition
function increases by 100 counts instantly, making the advanced features more accessible. If
the transmission had already learnt to 40 counts in adaptive mode, then when the shift lever is
pushed across into the performance mode it would become 140 counts.
In performance mode, driver recognition can learn from “sporty”, representing 100 counts, up
to “enthusiast” (200 counts). Counts can be gathered quickly as increases occur in blocks, while
a more graduated, single point decrease in counts occurs when you return to a less sporty driving
style.

Driver Recognition
A host of advanced features are accessible to the driver as part of the Driver Recognition
software with the six-speed automatic transmission.

“Driver Recognition
matches transmission performance to the current driving style by
considering acceleration and deceleration rates, brake and throttle applications, and cornering
speed, to ensure the vehicle is in the right gear at the right time without undesired gear
shifts,” Postgate said.

“The transmission ‘learns’ the driver's style and assigns a theoretical count system to certain
driving scenarios to determine the activation point of particular features.”
The count system extends from a “base” fuel economy bias (0 counts), through stages such as
“sporty” driver (100 counts), up to “enthusiast” (200 counts).
The transmission software recognises various performance-based actions, such as rapid
acceleration / pullaways, enthusiastic cornering, pushing the accelerator pedal through the
detent and moving the shift lever into performance mode, and increases the number of counts
accordingly.

By moving the shift lever across from adaptive to performance mode, the driver recognition
function increases by 100 counts instantly, making the advanced features more accessible. If
the transmission had already learnt to 40 counts in adaptive mode, then when the shift lever is
pushed across into the performance mode it would become 140 counts.
In performance mode, driver recognition can learn from “sporty”, representing 100 counts, up
to “enthusiast” (200 counts).

Counts can be gathered quickly as increases occur in blocks, while a more graduated, single
point decrease in counts occurs when you return to a less sporty driving style. All the Driver
Recognition features are available on all models fitted with the ZF six-speed transmission,
although certain features are more accessible on the sports XR models through a more
performance-biased calibration.

Enhanced adaptive shift strategy

The refinement of Ford's adaptive shift programming that occurred on BA Falcon has been
further enhanced on BF Falcon and SY Territory.
“The sheer capacity of the ZF transmission to allow for the real-time calculation of a variety
of parameters has enabled us to further refine the shift strategy, shift schedules and shift
pressures to cover the whole gamut of driving scenarios,” Postgate said.

“With corner, grade and load recognition, the transmission is able to adapt its functionality to
suit the situation as demanded by the driver.”

Adaptive modes include economy, performance, sports, uphill, downhill and towing.
The transmission software compares wheel speeds to infer lateral acceleration, as well as
longitudinal acceleration versus flat-road acceleration to infer uphill/downhill operation. It
then uses this information to assist the driver by inhibiting upshifts or enabling earlier
downshifts.

When towing, the transmission perceives the load as a hill and employs gear hold logic. At
highway speeds, it will cruise in the appropriate gear to account for the load being towed,
which could be 4th, 5th or 6th gear, depending on the precise situation.

The result is improved vehicle performance and fuel economy, as well as improved engine
and transmission efficiency.

Accelerator pedal detent and kickdown switch

An accelerator pedal detent feature has been introduced on all automatic Falcon and Territory
models, which provides physical feedback when accessing the kickdown switch.
When the accelerator pedal is pushed through the pedal detent to the floor, the kick-down
switch (which is integrated into the accelerator pedal mechanism) activates the kickdown
feature.

Depending on vehicle speed and the current gear, the kickdown switch will trigger a single or
double downshift. However, to prevent potential damage to engine or gearbox, no downshift
will occur if the engine speed is already too high to permit a lower gear from being selected.

Revised accelerator pedal map

The accelerator pedal map has been revised for more refined foot rotation versus engine
throttle-plate calibrations, which has improved driveability and resulted in more linear
vehicle performance.

Remote transmission oil cooler

The new remote transmission oil cooler fitted to all automatic I6 Falcon and Territory models
is a heat exchanger mounted to the engine block with a three-way coolant thermostat.
It serves the dual function of using engine coolant to provide rapid warm-up of the
transmission fluid during start-up, as well as improved cooling of the transmission under high
load/high temperature operating conditions.
“The rapid warm-up feature delivers a significant reduction in friction losses within the
transmission, contributing around 1.5 per cent to the overall improvement in fuel economy
within the BF program,” Postgate said. “The remote oil cooler also delivers further refinement
to shift quality, as well as reduced fuel consumption, due to better control of the operating
temperature of the transmission.”
 
This trans is used in R rovers, BMWs etc. We have rebuilt hundreds of them and are an official ZF Protech member. They are a good transmission without doubt.
The zf 6 has problems with the E clutch and also the bushes which wear and allow loss of pressure. They tend to have around a 100K life in normal usage.

One thing to remember is that the ZF Lifeguard fluid is engineered to the trans. Slip coefficient and chemical make up is specific for the ZF 6 and should be changed around 60000 miles along with the filter, which is part of the plastic sump.

They also have a tenancy to leak where the wiring harness sleeve, goes through the casing and this slowly reduces the fluid level. The converter lock up is blown OFF not ON as older trans did.

No matter what the above says towing will always put extra strain on the trans. This is why more sophisticated modern cars have the facility to remap when a trailer plug is connected.
 
official ZF Protech member.
Uh ???

They tend to have around a 100K life in normal usage.
I just turned over 100K !

One thing to remember is that the ZF Lifeguard fluid is engineered to the trans.
Lincoln says to use only Mercon SP.

upload_2021-8-14_22-6-21.png

ZF 6 and should be changed around 60000 miles along with the filter, which is part of the plastic sump.
I changed all 12-14 quarts, filter and then added a remote Wix filter and Derale cooler at 89,488 miles just after I bought the vehicle.

FP01_FilterInsideView_01399.jpg
FP01_FilterInsideView_01402.jpg
FP01_FilterInsideView_01403.jpg
FP01_FilterInsideView_01404.jpg

Below is what the remote filter showed after an additional 8485 miles.

FP01_WixRemoteFilter_02387.jpg
FP01_WixRemoteFilter_02390.jpg
FP01_WixRemoteFilter_02391.jpg


FP07_TransFluid_88488_Miles_01327.jpg
 
The website only allows 10 uploads, so .......

Can't have enough magnets, so I added these.

FP10_FilterVsMagnetLocation_01352.jpg

Not a good overall view of the first trans cooler, but it located under the passengers rear seat.

FP14_WiringAtTheFans_01414.jpg

The fans and temperature sensor for the fans also need wiring.

FP14_WiringUnderHood_01442.jpg
.
 
ZF Protech is a membership scheme by ZF for specialists that includes tech help from them by phone or site visits and regular courses on their latest transmissions.

Vid is in Spanish but you get the idea. Only 1 minute long.


I assume mercon SP is a makers version of Lifeguard. The steel sump and replaceable filter have been around for a long time. Range rover sports are built in such a way that you can not replace the sump without lifting or removing the body. We drop the plastic sump as far as it goes and then cut the suction pipe in half to allow the sump to be removed. Once done replaced with metal version. Some cars come with metal sumps from factory but I dont know which in the USA. In the UK some Audi,s have them.

We have known warranty claims to be rejected because the fluid is not ZF Lifeguard. I have been told its DNA marked.
 
Finally got the TBucket electrical system working like it should, so now I'm back to the Navigator transmission cooling project. I figured out that the connections for cooler in the radiator are metric so I needed to find a Metric-to-AN adapter, the Russell #670560 fitting was exactly what I needed. What was NOT obvious with a thread gauge is that 11/16-16 and M18-1.5 are almost the same thread. When the US thread did not work, I ordered the metric adapter. I did know for sure until I tried the metric M18-1.5 in the radiator.

FP03_MetricToANAdapter.jpg

FP02_2861
FP02_UpperTransCoolerLine_02861.jpg

BTW, the OEM cooler in the radiator has an internal gasket. Be careful when removing the fitting, it could easily fall inside and all your coolant will come gushing out. I found this out when I tried to install a NPT to AN fitting and was pushing in to install the new fitting.

The O-Ring on the fitting does not seem to be needed, but I put one on any way. I drove the vehicle without the o-ring and had zero leaks.\

FP02_2859,2862
FP02_AN_vs_OEMFitting_02862.jpg
FP02_UpperTransCoolerLine_02859.jpg
FP02_UpperTransCoolerLine_02861.jpg
I cut the barb off the OEM external cooler and used a compression fitting to AN adapter. My goal was to convert all fittings to AN in the front grill area. I would not give me a second chance at converting OEM external cooler, the tube was very short.

Like the one below.

https://www.summitracing.com/parts/sum-2200078b

upload_2021-8-26_20-31-9.png

FP05_2920
FP05_ConvertOEM_CoolerToAN_02920.jpg

The system is starting to take shape …….
FP06_2857
FP06_ThermostatMountedInNavigator_02857.jpg

https://www.summitracing.com/parts/der-54008

The cooler is a Derale 40 row Stacked Plate Cooler with -8 ORB fittings, fittings are included with cooler.

upload_2021-8-26_20-32-0.png

https://www.summitracing.com/parts/der-25719

The thermostat is also Derale #25719 with ½ inch NPT threads.

upload_2021-8-26_20-33-22.png

More to come before this operational !!!
 
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Well I ran out of time, 10 minutes is just NOT enough when you have 10 images (10's the limit per post)
Like we can't post again, it just breaks up the post so it doesn't provide as much info in a logical sequence. I could work with 15 to 16 images per post.

https://www.summitracing.com/parts/rus-670560

I was trying to include a link to the metric adapter in my post above.

I know how to make these changes to a Xenforo website, but .......
 
Ever consider using a condenser as a cooler? Maybe overkill but would provide mega surface area.
No I didn't consider a condenser, but I'm kinda concerned about how much I'm restricting the flow to the radiator with what I have now.

Wouldn't that be a kick in the ass if I have to add an engine oil cooler now to help the radiator !
 
Lincoln in their great wisdom spec'd the trans cooler lines coming from all the way back at
the trans to the front would have Rubber connections at the front. Great, so when the rubber
goes to shit, you have to try and snake that new line in around corners and between the engine
and cross-member. Probably going to need to raise the engine to get enough room. So one of
my goals for this project was to eliminate that problem. I did just that with some SS tubing.

Going from this .......

FP07_TransHosesUnderNav_02959.jpg

To something much better ........

FP07_TransHosesUnderNav_02980.jpg
SS tubing is notorious for being hard to seal, so I took some extra steps to ensure a leak
free connection !

The chamfering tool is 60° and the flare for AN fittings is 37°, meaning the chamfer is touching
in the bottom of the flare. So I had to rotate the drill around at an angle to polish the entire
surface of the flare.

Then I polished the inside of the flare on my buffer to get a really smooth surface like you
see below.

FP07_FlaringSSTubing_02967_02970_02972.jpg

Most AN hoses end with a female connection, but so does the SS tubing. So how can
you connect a hose to tubing ??? Now you can use a Coupler, and if you are going from
one size to another, then a coupler is what you will need. But it also adds another
SEALING SURFACE for a possible leak.

https://www.summitracing.com/parts/rus-660361
https://www.summitracing.com/parts/rus-661771
FP07_RussellCoupler_PN660361.jpg upload_2021-8-27_17-42-14.png

My line size was NOT changing so I was happy to see I could use a Hose-to-Male connection
made by Vibrant Performance like the one below.

https://www.summitracing.com/parts/vpe-24008
Vibrant Performance 24008
upload_2021-8-27_16-52-11.png

FP07_SS_to_HoseConnection_02974.jpg

Below is how it worked into my situation.

FP07_SS_to_HoseConnection_02982.jpg

Once I got the system plumbed, I wanted to flush the lines from all the particles created
when I cut the hose with a hack-saw. The hose has a SS layer, plus all the rubber bits that
end up in the hoses. None of it any good for the transmission.

I had an Aeromotive 100 micron filter that I had not used, so I plumbed that into my
flushing system. Otherwise all I would be doing is circulating the trash. Wish I had a
better filter, but it's what I had.

I found a few bits of what you see below. Maybe it's was not worth the trouble, what do
you think ???

FP07_FilterAfterFlush_02983.jpg

Below is my setup for flushing the new components of my trans cooling system. I did the
same thing for my fuel system, but bypassing the carburetor.

.
 
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