Engine/Transmission (1998.5 - 2002) NV-5600 cooler and filter

[Gary - K7GLD]

Nothing earthshaking - just a pictorial showing one half a NV-5600 with a Fast Cooler, and the other half with a filter installed. The Fast Coolers and transmission lube filters are available thru Genos thru this board.



The purpose of the coolers are to both provide added transmission lube cooling and also add lube capacity for better overall transmission operation and lifespan - looks like this installed:



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The added PC-type heatsink was done as an experiment to see if it added any significant cooling effect to what the Fast Cooler already is supposed to provide - I have NO illusions as to any vast benefit, just figured it was worth a try. As can be seen, I also have mounted a heat sensor to monitor the case temps in down-the-road situations - perhaps not the same as an actual temp sensor bathed my the lube, but all I have at the moment. The addition of these 2 items, plus a little overfilling allowed 6 quarts in the transmission.



The other side - the filter side also has an added heatsink - and the filter obviously deflects a percentage of operational lube flow into a cavity, then thru a small filter, then back out to the main transmission case.



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Reports from users indicate the filters really catch lots of crud, and I also added a powerful magnet inside the filter cavity of mine for some added benefit in attracting and retaining damaging ferrous materials. At 50K miles, and several lube changes, this was the first time I'd had the side covers off and attempted to clean out the transmission sump and magnet - both were very filthy, and certainly needed cleaning!



A couple of 50 mile runs over a pair of local 5000 foot mountain passes while towing my 12 foot fishing boat and gear delivered a nominal 50 degree temp rise - ambient outside temps were 75 degrees, the transmission monitor registered +- 50 degrees higher - I'm very curious what other users with a setup like mine - or just the coolers alone, typically see in terms of temperature rise in varying situations?



My digital temp monitor tops out at 156 degrees, so I'm pretty certain a hot summer day towing our 5th wheel will put it well off scale - but I also have an infra-red handheld temp monitor to use at higher temperatures...



Any comments?

 

[ILIANBG]

Hey Gary, what type of transmission fluid did you use? Did shifting change after having more fluid? I am thinking of adding fast coolers. I already have the filter.

 

[Gary - K7GLD]

Hey Gary, what type of transmission fluid did you use? Did shifting change after having more fluid? I am thinking of adding fast coolers. I already have the filter.

After testing a couple of substitute transmission lubes a few years back, I found they provided significantly poorer shifting in my specific transmission than the OEM stuff - so went back to, and have been using it ever since. I don't really HAVE any shifting problem - just the typical minor characteristics of the 5600 - "notchy", tight shifting, and the very minor tendency to "catch" a gear in the 2-3 and 3-4 shift when first starting out on a cold morning if shifted too quickly - and even that disappears within a couple of blocks.



My primary goal here, as an RVer, was to provide for longer transmission life by providing more and cooler lubrication - along with the advantage of the filter and cleaner lube. Now, what I need to do, is drive it under varying conditions and temperatures, and see how my temp readings compare with other users who have done varying mods of their own, to see if my efforts are providing any visible benefits.

 

[Froadin]

Might want to think about a simple heat shield to keep that exhaust heat from getting those heat sinks hot.
Be a shame to have the exhaust actually put heat IN your transmission.

 

[fkovalski]

Might want to think about a simple heat shield to keep that exhaust heat from getting those heat sinks hot.

Be a shame to have the exhaust actually put heat IN your transmission.

Furthermore... might want to have the fins pointing in a downward direction such that water and other schmutz can fall out.

 

[Gary - K7GLD]

Might want to think about a simple heat shield to keep that exhaust heat from getting those heat sinks hot.

Be a shame to have the exhaust actually put heat IN your transmission.

Actually, the position and location of the added heatsink on the exhaust side is well away, and out of line of airflow from the exhaust at that location - as well as pretty well of of line of road trash - the pic showing the transmission case shows what it has managed to attract on 50K miles of travel - not much!



I chose the horizontal fin positioning as to (hopefully!) get more airflow along their axis than presumably would occur if they were vertical - but on the other hand, the size and location of the heatsinks will quite likely not add a great deal of cooling anyway...

 

[6naline01]

NV5600 cooler and filter

Gary that looks really good. What kind of sealant did you use? Did you use any type of gasket. Mike

 

[Gary - K7GLD]

Gary that looks really good. What kind of sealant did you use? Did you use any type of gasket. Mike

I used a Suzuki branded grey colored hi-tech sealant left over from my motorcycling days, very expensive at over $25 a tube when I bought it - but now I think the grey Permatex is lots cheaper and probably the same stuff - this stuff NEVER leaks, and stays pliable for later removal if needed - no gaskets on the cooler side, but a pair on the filter side. I used JB Weld to attach the heatsinks, and a heavy weight to maintain good contact metal-to-metal for best heat transfer.



I'd sure like to see some random temperature readings from guys here who have transmission temp sensors installed, so I have something to gauge my setup against... Oo.

 

[Gary - K7GLD]

Still no comparative readings from other NV-5600 guys with temp gauges installed?



ANYWAY, towed the 5th wheel over the same two 5000 foot mountain passes within the last few days, and saw a max of about 60-65 degrees above outside ambient - not too bad with the 70 degree or so weather we're currently getting - but I have little doubt the higher summer temps will put my temp gauge over it's 156 degree limit.



I'm pretty sure several guys have posted transmission temps over 200 in heavy summer towing - guess I'll have to do a search...

 

[Gary - K7GLD]

OK, a search gave some good readings - here's one thread:



https://www.turbodieselregister.com...on-1998-5-2002/76853-how-hot-your-nv5600.html



This is a good quote from that thread:

Stock lube, one Fastcooler, truck @ 7600lbs:

90 degrees ambient air temp, cruising 65mph: 150-165 degrees

below 50 degrees ambient air temp, cruising 65mph: 125 degrees

towing 7000 lb. TT 90 degrees cruising 65mph in 6th gear: 185 degrees

towing 7000 lb. TT 90 degrees cruising 60 mph in 5th gear: 155 dregees

Thank God for a good search feature on this board! Oo.

 

[EricBu12]

Gary,



I have the fast coolers on mine and I like the heat sink idea... .



I have a temp probe that is in the top of the fast cooler. . don't know if it only gets splashed with lube but it must at least... I use Amsoil MTL fluid and it is overfilled a bit too. .



I have a 36' 5th toyhauler and a 14' utility for another toy and I top out at 210 going up a steep hill in warm weather like 87 deg. I have a horton fan so pos. airflow happens when pulling



Otherwise, running solo, it runs between 150 to 170 dep. on temp outside.

 

[Gary - K7GLD]

Gary,



I have the fast coolers on mine and I like the heat sink idea... .



I have a temp probe that is in the top of the fast cooler. . don't know if it only gets splashed with lube but it must at least... I use Amsoil MTL fluid and it is overfilled a bit too. .



I have a 36' 5th toyhauler and a 14' utility for another toy and I top out at 210 going up a steep hill in warm weather like 87 deg. I have a horton fan so pos. airflow happens when pulling



Otherwise, running solo, it runs between 150 to 170 dep. on temp outside.

Thanks Eric - the more info, the better. I'll have to rely upon transmission case temps for my readings - I already have too many monitoring gadgets competing for attention - but surely the case temps follow lube temps pretty closely...

 

[PAckley]

Trans cooler/fluid/temps

Gary:

Thanks for the posting, I should be able to supply some interesting data for you shortly. I tow a 24x8' race trailer, and depending on what car I race, weighs 7-8,000#



Bought truck used, $9k, and added lots of after-market, including a rebuild from Standard Transmission, FT. Worth, TX NV5600. Old trans had not 6th synchro, and towing to VIR temps went to 210* and then I heard bearing noise. I managed trip, stopping to let cool, replaced fluid at track, and made it home and had trans pulled and exchanged. I also upgraded to 1 3/8" output shaft, 13" (HO) flywheel and Con OFE SBC clutch.



Short tow last week saw temps go to 208* when ambient was 90* without coolers and Amsoil synthetic trans fluid recommended by Standard Trans.



Installed coolers and over-filled trans and will be towing to Cincinnati this next weekend.



I also will use less brute force torque in 6th gear and use 5th on occassion to see what difference it makes. Previously I have noticed the temperature just steadily rises with no ability to reduce temp, so hopefully coolers will do something material, as I feel <200* is my target zone, and hope I can maintain 190*.



The trans exchange opened my eyes:



1. I avoided auto as the stories of failure scared me away

2. Lots of NV5600 problems reported here

3. NV5600 1 3/8" trans are becoming difficult and expensive to find for rebuild, new can be located for $5600!

4. Most of returned cores to Standard are worthless, I was fortunate and got my $1,000 core refund. Also was able to trade up from 1 1/4" to stronger 1 3/8" output shaft which may not be possible for others.

5. I have done everything for trans longevity, except avoid high-torque 6th gear charges up big hills which supposedly really strains 6th gear. I have been able to keep EGT below 1200* in all cases, but Virginia does not have Colorado mountains!

6. The SHO VP44 puts ample power out, use Edge mileage or Tow settings only occassionaly while towing and get 14 mpg with 4. 1 axle and no attempt to reduce consumption (stay at 55060 mph)



Hope I can help with trans study!

Phil

 

[Gary - K7GLD]

ANY info you can provide will be appreciated Phil - in my case, towing a similar load to yours, I see a worse case temp rise of about 60 degree above ambient - and that is when pulling some pretty decent local grades - too bad I didn't do the "before" temp test. but you have that covered, and I appreciate it - looking forward to further readings from your setup.

 

[PAckley]

Gary et al:



So I am back from a long tow from DC to Nelson Ledges, 24' trailer weighing probably 7000#



The new (Standard Transmisison late model 1 3/8" output shaft, SBC HO flywheel, Con FE clutch, Genos' fast cool) or whatever you call the "radiators"

that go onto the PTO area, with Edge w/juice trans temp sensor.



Ambient temps were high 70's-low80's



Towing at constant 65-70 mph at 2200-2300 rpm.



Temperatures just constantly creep up and after two hours temps are over 205 degrees, and continue upward to an eventual high of 238*



I found I could slow down to 60 and ease up the hills (Alleghenies foothills are no match for Rockies) and keep temps around 220-225*



I was hoping the fast coolers would make as substantial difference but they did not seem to, although the extra Amsoil must have helped.



A short pitstop (I drove the whole 6 hours on one tank=14 mpg/63 mph ave) of 5 minutes lowered the temps 30 degrees, then the upward creep all over again.



I called Standard Transmission (ST) and they say these trans always run hot and expect 25-30* more than engine temperature. In any event, these temperatures are actually much higher than the transmisison that ultimately had to be replaced.



I wonder if the Dodge fluid for these is better? Amsoil is what ST recommended. It shifts smoothly.



So I continue concerned, as this is my first replacement trans, and they are $4400 expensive, plus installation. My only next comparison is to change fluid to the special Dodge or equivalent fluid. Any thoughts? 60 degrees above ambient seems like nothing (90+60=150!) I am way above that!

Phil

 

[PAckley]

Trans temps get even hotter than imagined before. I have seen 245* on long towing trips through gradual hills at high speed. I have concluded that unless I can actively cool through either pump or fan, I will have to stop the vehicle and let the oil cool. Returning from Mid-Ohio race circuit, temperature dropped from 240* to 180* in one hour while refueling truck and dinner break for one hour. Amsoil claims they are good up to 300 degrees. The only other experiment would be to change fluid to see if temps change. Most people do not monitor trans temps so perhaps this is TMI Too much Information! Any other input would be apprecaited here

 

[Gary - K7GLD]

Trans temps get even hotter than imagined before. I have seen 245* on long towing trips through gradual hills at high speed. I have concluded that unless I can actively cool through either pump or fan, I will have to stop the vehicle and let the oil cool. Returning from Mid-Ohio race circuit, temperature dropped from 240* to 180* in one hour while refueling truck and dinner break for one hour. Amsoil claims they are good up to 300 degrees. The only other experiment would be to change fluid to see if temps change. Most people do not monitor trans temps so perhaps this is TMI Too much Information! Any other input would be apprecaited here

HMMmm - the driving tests I did were only about 50 miles, and a couple of decently long and steep mountain grades - might have to test again on a longer run for added data...



Thanks for the info.

 

[Grizzly]

What would be a safe temperature for a NV5600 while towing a 10K 5er? Which transmission runs cooler the NV5600 or the G56 while towing the same 5er? Both cases with stock oil.

 

[PAckley]

Gary:
Your tests are not long enough for proper evaluation. If I were to post temperatures after 50 miles they would be equal or less to your numbers. The transmission temperatures just rise steadily over time and effort. The transmission is a heat sink, and not like the engine that either cools or does not cool (a 50 mile test is appropriate). So on this latest 7 hour tow, after 1. 5-2 hours I am doing fine at approximately 200 degrees (ambient was 90+ degrees) The next hour the temp gradually increased from 200 to 225, increasing to 235+ at hills.

 

[Grizzly]

Gary:

Your tests are not long enough for proper evaluation. If I were to post temperatures after 50 miles they would be equal or less to your numbers. The transmission temperatures just rise steadily over time and effort. The transmission is a heat sink, and not like the engine that either cools or does not cool (a 50 mile test is appropriate). So on this latest 7 hour tow, after 1. 5-2 hours I am doing fine at approximately 200 degrees (ambient was 90+ degrees) The next hour the temp gradually increased from 200 to 225, increasing to 235+ at hills.

Can anyone tell me what a safe temperature is for an NV5600 towing a 10K 5th wheel with stock oil?