Hot NV5600 !!!

[Lmoore1624]

While doing a short Easter vac from Las Cruces to Tucson and back, I noticed my trans temp gauge climbing really hotter than I would like. Pulling TT approx. 7500lbs. Going over, outside temp approx. 75 degrees with trans around 200-210. Coming back, outside temp approx. 85 degrees with trans around 220-240.

>Dual FastCoolers installed.

>Running 7 quarts Redline MTL.

I'm worried when summer hits out here with 100+ outside temps, that my NV5600 may melt into a puddle of molten cast-iron!!



Has anyone tried a different cooling method for the 6-speed manuals?



thanks ... ... ... ...

 

[steved]

Sounds pretty normal to me... I have seen 235*F empty without coolers before. I see around 200*F empty with 100*F ambient temps and coolers now. I could easily see the 40*F increase towing 7500#s.



The fluid should handle it... check with redline and see the max temps it can handle, but its probably more than 300*F.

 

[SMorneau]

Seems like there would be a good market for an add on cooling system for these trannies. A pump, pickup, filter, exchanger and some simpleton controls. Maybe the pickup and return could be built into side plates to make it a bolt up affair.

Since no one has done it, it must not be necessary.

 

[04blackcherry]

I've heard both sides about how much fluid is too much in the NV5600. Some say overfill and some don't. The don'ts say overheating is possible with too much oil. Look at the blogs and maybe call some transmission shops that know this transmission to get an educated idea. I know the Redline MTL is correct for this application. I just put some in mine.

 

[SMorneau]

I debated on adding a full 6 qts or not. After not getting a full 5 quarts in tru the fill hole I pulled the shifter to take a look. There is a lot of empty space and the surface of the fluid looks to be a long way down! I can't believe the addition of the an extra qt on top of the full 5 qts is going to hurt this transmission by making it overheat. I find it very easy to believe the extra fluid is carrying heat away from the upper shafts and gears. Of course I have been wrong before.

 

[amsoilman]

I installed the Amsoil (MTF) several years ago at around 35 K as i recall (without looking it up in my records) and I put in the required amount which is 5 QTS. The fluid I installed is still in it at this time with just over 90 K miles. Transmission still shifts very nice and smooth, and does not seam to get hot at all.

 

[Curious Dave]

Smorneau, Lmoore1624,



I have had the high temp. situation before. I too have the FAST coolers. My recent service I added 10 quarts thru the shifter access. The trans is fine. During the good weather months I haul a 16k lb. fifth wheel. The trans heats up then. The FAST definitely help. I also had to slow down to @ 60 - 65 when it gets up to 220. It only takes a few miles to cool back down to 190. I made my own side covers out of 1/4 alum. plate and I have come up with a design for a filter and cooling system. I have thought about using a FASS pump. . but I can not get any information from FASS regarding the reliability of their pumps with repect to viscosity of the oil. I do know that there is a company that makes 12v pumps specificaly for gear oil though. The entire system would run @ 1k for doing the system fight. I prefer to run Earls type lines and all on all my stuff. The cooler would probably be something like a Griffin. P/U & return would be bottom of 1 side plate and top of other. You can pick up a universal spin-on filter from NAPA. I thought about the expense being 1k. . but considering the trans replacement can run 5k... It seems like a no-brainer for heavy use.

 

[Mark31]

I believe I saw something on a Nascar program a few years ago about cooling rear end oil. Maybe a racer's supply might give you some ideas. Mark

 

[Curious Dave]

Differential Fluid Cooler -- BimmerWorld Online Store



Try this - guys.

 

[jelag]

If your towing your 5er in 6th gear and are overloading the transmission expect 6th gear failure at around 160K miles... . we tow a 20K lb trailer with our 04 and did the transmission in around there...

We had a temperature gauge on the transmission but never saw the temperature as high as your reporting... anything much over 250*F will damage the oil and cause it to break down unless you run a full synthetic...

We currently tow at above 55 mph on straight and level in 6th and move to 5th as soon as we hit a grade or below 55 mph... we don't load the transmission in 6th... we also run a full extra qt of oil poured in from the top... . and for us that seems to have worked...

We had a F550 with a 6 speed that used ATF and that transmission actually ran the oil to a cooler in the radiator, and in the return line we installed a 10 micron filter... once a year we'd change the filter...

Geno's has a kit to remove the PTO covers on the side and install an enlarged cover with cooling fins and extra capacity... I'd do that first before I tried to pump it around... .

Hope this helps. .

 

[steved]

I debated on adding a full 6 qts or not. After not getting a full 5 quarts in tru the fill hole I pulled the shifter to take a look.

If you pull the covers, there is a "sump" in the bottom of the trans that holds about 3/4 of a quart of oil if you only pull the bottom PTO cover bolt.

 

[SMorneau]

I drain trough the bottom bolt hole but then pull the side cover to clean and inspect. Still wouldn't hold 5 quarts... probably about 4 -1/2.


My neighbor has an older 7. 3 PSD and it's manual has a cooler loop. Apparently the pump is built into the transmission.

 

[SMorneau]

Dave,

I think the fass pumps would be too expensive. Especially, since a pump failure would not be critical.

If you just recently did the 10qts I would be interested to know how that impacts your temperatures.

 

[steved]

I drain trough the bottom bolt hole but then pull the side cover to clean and inspect. Still wouldn't hold 5 quarts... probably about 4 -1/2.





My neighbor has an older 7. 3 PSD and it's manual has a cooler loop. Apparently the pump is built into the transmission.

If you swab the contents out, they hold five quarts... but it takes time to do that. I usually use a gob of paper towels and wring them out several times.



I thought someone had built a lube pump, cooler, filter circuit for the NV5600 a few years back?? IIRC, it was basically a drilled/tapped the PTO cover for the supply and return, a large hydraulic cooler, and a spin-on hydraulic filter. Do a search on here, maybe in the 2nd gen forum, but I know this was discussed at length.



Lube pumps run right about $100, and they should survive quite a while if placed on a thermostat switch.

 

[SMorneau]

I found this: http://www.atsdiesel.com/additional...310-910-INST Force Cool Instructions v1.0.pdf

$1200! I don't think so.

 

[SMorneau]

Here is a pump that should work for $180.

Tilton Engineering 40-524 - Tilton Transmission and/or Differential Oil Cooler Pumps - Overview - SummitRacing.com



Here is a cooler with fan that for under $200.

Derale Cooling Products 15850 - Derale Cooling Products Atomic-Cool Remote Fan Mounted Oil Coolers - Overview - SummitRacing.com



Figure another $200 for some nice lines and automotive grade wiring components and temp switch.



That would be about $600 in parts for a non-filtered system. I would have a disable switch in the cab for the cold weather season, a relay that turned the power off when the ignition was off, and a temperature switch mounted thru a side plate that would turn on the pump and fan, via a second relay, when the temp hit about 140F. I may just have to do this...



If anyone is well versed in thermal transfer maybe they could give some feedback on cooler size and gpm.



Scott

 

[Gary - K7GLD]

We currently tow at above 55 mph on straight and level in 6th and move to 5th as soon as we hit a grade or below 55 mph... we don't load the transmission in 6th... we also run a full extra qt of oil poured in from the top... . and for us that seems to have worked...

Much the same as I do, except I've also added a FastCooler on one side of the transmission case, and a filter on the other, plus added cooling fins:



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Here is a pump that should work for $180.

Tilton Engineering 40-524 - Tilton Transmission and/or Differential Oil Cooler Pumps - Overview - SummitRacing.com

If I was doing lots of heavy hauling/towing, I'd sure go for something like that!



In any case, temps s high as the OP stated certainly do NOT sound right - even in the WORSE heavy towing in long steep grades, the outer case temp on my 5600 rarely exceed 160 degrees with my setup, and that only for a few minutes - I also am running about 8 quarts of lube, with the extra cooler/filter capacity and overfilling - NO transmission issues so far...

 

[Grizzly]

If your towing your 5er in 6th gear and are overloading the transmission expect 6th gear failure at around 160K miles... . we tow a 20K lb trailer with our 04 and did the transmission in around there...



We had a temperature gauge on the transmission but never saw the temperature as high as your reporting... anything much over 250*F will damage the oil and cause it to break down unless you run a full synthetic...



We currently tow at above 55 mph on straight and level in 6th and move to 5th as soon as we hit a grade or below 55 mph... we don't load the transmission in 6th... we also run a full extra qt of oil poured in from the top... . and for us that seems to have worked...



We had a F550 with a 6 speed that used ATF and that transmission actually ran the oil to a cooler in the radiator, and in the return line we installed a 10 micron filter... once a year we'd change the filter...



Geno's has a kit to remove the PTO covers on the side and install an enlarged cover with cooling fins and extra capacity... I'd do that first before I tried to pump it around... .



Hope this helps. .

Great post Jim. I'm reading this thread with much interest since I too have an NV5600, 6 speed and tow a 10K lb 5th wheel in the Rocky Mts.



So far I take a temperature reading with my Fluke 62 Mini Infrared Thermometer at each stop, which hasn't shown anything higher than 150* F. What transmission temperature gauge is recommended.

 

[SMorneau]

In any case, temps s high as the OP stated certainly do NOT sound right - even in the WORSE heavy towing in long steep grades, the outer case temp on my 5600 rarely exceed 160 degrees with my setup, and that only for a few minutes - I also am running about 8 quarts of lube, with the extra cooler/filter capacity and overfilling - NO transmission issues so far...

I have seen temps of 200+ running empty in 80 degree weather. It takes several hours but it easily gets there. With a load another 35-40 deg should be easy to attain. I would rather have a powered cooler than a fast cooler. The only downside I see is exposure to loss of fluid from damage to the external plumbing or cooler A lot of careful placement and guarding should minimize that risk. I had something break a temp sending plug off once already. Fortunately I caught it before it had leaked any appreciable amount. Pure luck, if I had been on a trip I would have lost the transmission.



I would like to make this trans last forever... the truck has had a total of 5 different transmissions in it and that's not counting the first time it failed and the dealer "fixed it". :{

 

[Gary - K7GLD]

I have seen temps of 200+ running empty in 80 degree weather. It takes several hours but it easily gets there. With a load another 35-40 deg should be easy to attain. I would rather have a powered cooler than a fast cooler. The only downside I see is exposure to loss of fluid from damage to the external plumbing or cooler A lot of careful placement and guarding should minimize that risk. I had something break a temp sending plug off once already. Fortunately I caught it before it had leaked any appreciable amount. Pure luck, if I had been on a trip I would have lost the transmission.



I would like to make this trans last forever... the truck has had a total of 5 different transmissions in it and that's not counting the first time it failed and the dealer "fixed it". :{

I can only guess that individual transmission internal tolerances cause such high temps - and even though my own measurements have been taken at the case, rather than an internal probe submerged in the lube, I can't believe there would be a consistent 50-100 degree difference in the 2 methods - my first pic shows the probe and mounting location.



Sorta makes me wonder if there ARE internal tolerance issue that have, and are, affecting the lifespan of some of the premature failing NV5600's - also evidenced by the widely varying shifting characteristics from one transmission to another, and extreme sensitivity to type and brand of lube used.



I've monitored my own for as much as 1300 towing miles in mixed mountain and flatlands travel, 650 miles in a single day with nothing but bathroom stops - verified temp readings with my infra-red temp gun - and seen a typical 40-50 degree rise above ambient in the flats, and about another 20-30 in the hills - but the temps always quickly return to their lower readings once the grades are past...