NV5600 and quart overfill = hotter trans?

[steved]

Whereabouts on the cover?

Mine is in the cover itself... we drilled and installed (brazed) portion of a pipe collar into the lower half of one of the covers before I had fast coolers.

 

[steved]

Gotcha. . what fluid are you running? Have you tried amsoil, supposed to be good to 300*F...







Did you buy 2 sets? My Fast coolers only came with one tapped cooler.

Redline MTL works the best in my application... Amsoil lasted around 10k before it started going the other way. Amsoil was not much different than any of the others... I installed the Fast Coolers at the same time I tried Amsoil. The Amsoil had a single trip from PA to Key West (with the slide-in camper and small trailer) and shortly afterwards started falling off... and it was only in from October 2006 to January 2007 (not exactly hot months).



I have ran:



Amsoil MTF (whichever one is there synchromesh version)

Pennzoil Synchromesh

Royal Purple Synchromax

Redline MTL

25% Redline MT-90 and 75% Redline MTL blend

25% Royal Purple Max Gear 75w140 and 75% Royal Purple Synchromax Blend.



I have also tried the limited slip differential (LSD) additive and Lucas transmission additive without much improvement.



In ****my**** trans, Royal Purple was the worst performer and Redline has been the best (in longevity of shifting qualities). I qualify this statement with "my" trans because others have had good luck with fluids that don't work for me... I actually run RP in both the differentials (85w140 Max Gear) and the transfercase (Synchromax), so its not like I have anything against their product.

 

[Gary - K7GLD]

... is that sending unit just epoxied to the case? Steve, how are you getting your readings?

Mine is secured by a thin film of Silicon cement - I've verified accuracy with a laser type infra-red external gadget - but reading case temps is likely less reliable and accurate than using an actual sender in direct contact with the lube.



My sampling setup, as can be seen, is a wired digital unit that only reads as high as 156 degrees - and I've only seen it go out of range twice, in summer temps of about 100 degrees ambient, as we were towing our trailer up long steep grades - and even at that, it was only out of range for a couple of minutes, since it only went out of range as we crested the hills. It then quickly dropped back down to the 40-50 degree or so differential vs ambient.



I placed my temp sensor on the transmission case slightly away from the covers, rather than on the covers themselves, because I suspected the lube temps right on the heat sinks might be artificially lower, IF the coolere ARE significantly reducing lube temps. Although, the transmission case itself likely provides the largest and most effective heat sink for cooling the lube.



I'd like to be able to more accurately read the actual lube temps - but really don't want any more permanant gauges installed than I already have, and these digital types are easily moved from one location to another, and probably accurate enough for the level of checking I'm usually involved in.



I make no claims as to "laboratory" type accuracy - but feel that what I *do* come up with is accurate enough to suit my purpose, and doubt there is any radical difference between lube temp and transmission case temp - it probably just takes a bit longer for case temp to match lube temp...

 

[steved]

It really doesn't matter what temperature guage you have, it is nothing more than a baseline as most are so inaccurate they probably are not even really close.

 

[JHorst]

drilled and tap the fast cooler that did not have the fill plug so both had sensor ports. The one sensor is analog and the other is digital. The digital is also switchable with the engine oil temp via toggle switch. So I know this sensor is reading in the correct range (also calibrated before install). The analog is on the passenger side and reads the same. I think the lube is moving around a lot when driving that the location in the coolers or behind the coolers, side to side, etc is all the same temp. When I stop with the engine off, the side with the fan cools down at a faster rate then the other side.

 

[Diesel Gunner]

NV 5600 Overfilling

I just serviced my trans. Removed Fast Coolers and drained as much as possible of the Mopar lube that I had installed when I put them on. At that time I only filled to fill port on trans. It seemed to be getting grouchy more often and thought that a drain and refill would be a good idea.



The $20/qt of the Mopar lube dulled my enthusiasm. So I decided to give the Red Line MTL a try. After Fast Coolers were reinstalled I filled to the service plug. Re-installed the service plug and poured 2 more quarts through the shift tower.



Well, the trans runs at the same temp as the dif and nothing is coming out of the vent or other places. I have towed the TT and ran it hard. The shifting is much better (seems fresh fluid does this to most of them) and I even changed the reverse switch without any fluid coming out. It might be just bit quieter. My temp sensor is located in the botton of the Fast Cooler.



So far (about 1500 miles) I would say that I would do it the same way again.

 

[MMeier]

I just serviced my trans. Removed Fast Coolers and drained as much as possible of the Mopar lube that I had installed when I put them on. At that time I only filled to fill port on trans. It seemed to be getting grouchy more often and thought that a drain and refill would be a good idea.



The $20/qt of the Mopar lube dulled my enthusiasm. So I decided to give the Red Line MTL a try. After Fast Coolers were reinstalled I filled to the service plug. Re-installed the service plug and poured 2 more quarts through the shift tower.



Well, the trans runs at the same temp as the dif and nothing is coming out of the vent or other places. I have towed the TT and ran it hard. The shifting is much better (seems fresh fluid does this to most of them) and I even changed the reverse switch without any fluid coming out. It might be just bit quieter. My temp sensor is located in the botton of the Fast Cooler.



So far (about 1500 miles) I would say that I would do it the same way again.

So, how many qts did yours take, doing it that way?

 

[JWadford]

i know if i overfill a pto on a 994f loader it will overheat like crazy, due to the oil is actually cooled by the metal housing, too much oil and its more volume than it can keep cool, i imagine when you overfill your transmission it will do the same thing, more oil, less surface area to sweep the heat away, i wouldnt overfill unless i was running a cooler, also oil does foam, doesnt matter what brand, cold oil will foam like crazy even with top anti foaming agents, after the oil warms up, it releases the air faster, but cold oil is like syrup

 

[Diesel Gunner]

MMeier, I put 8 qts total into my trans.

 

[Gary - K7GLD]

MMeier, I put 8 qts total into my trans.

YUP - about the same as I'm running in mine...



By the way, how's things back down there in my old Vacaville stomping grounds?

 

[kkreigh]

I have had a Westach guage and sending unit ( sensor in Fast Cooler port) on my NV5600 since 2001. I have never overfilled my transmission. I have always run the Mo Par Manual Transmission Lubricant NV3500 part # 04874464, MS 9224. I have recorded transmission temperatures keeping records of load, speed, Type of highway, A/C on or off/ ambient air temperature, elevation above sea level. I have found consistently the outside ambient air temperature is the main factor in elevated transmission temperature.



The highest NV5600 temperature I have seen is 175* at 80 mph sustained interstate highway, 867 feet above sea level, 97* air temp, with 3000 lbs on trailer.



An examlpe of Outside air temperature effect is the same highway as above with 70 mph, trailer loaded with 13,000 lbs, outside air temp 55* resulted in 155* NV5600 temperature.



I offer this info as some possible help with a base line for comparison. Hope it helps

 

[AH64ID]

I'm due for a fluid change so I am bringing this back up. .



I did 7 qts on my last fill, with Fast Coolers and will probably go back with that, but wanted some more current opinions.

 

[blacksheepdiesel]

The reason for overfilling by putting in 7 qts total is to lubricate the rear bearing, not to make the transmission run cooler.

It would be great for someone who knows about metallurgy of bearings, gears and shafts to weigh in here so we know what temp is too high. I really think that the temps mentioned in the above posts are nothing to worry about.

What I have learned from the rebuilders is that the times temperature is a problem is because there is no lubrication for the bearing.

Godspeed,
Trent

 

[steved]

The reason for overfilling by putting in 7 qts total is to lubricate the rear bearing, not to make the transmission run cooler.



It would be great for someone who knows about metallurgy of bearings, gears and shafts to weigh in here so we know what temp is too high. I really think that the temps mentioned in the above posts are nothing to worry about.



What I have learned from the rebuilders is that the times temperature is a problem is because there is no lubrication for the bearing.



Godspeed,

Trent

The original point of this thread was whether overfilling was causing something that was lubricated at a normal fill to run hotter because it was flooded. So the increased temperature would be indicative of a potential lubricant starvation issue, and a very real reason for concern.

 

[AH64ID]

I am still undecided on if its from lubrication starvation or too much fluid... I still look at that 90% or more of NV5600 owners go by the book, and its known to be one of the stouted 6 speeds out there.

 

[macdaddy]

I am still undecided on if its from lubrication starvation or too much fluid... I still look at that 90% or more of NV5600 owners go by the book, and its known to be one of the stouted 6 speeds out there.

I try to stay out of these threads dealing with the "extra" oil in the 56 honey's. I work in the oil industry and deal with allot of lubrication issues, pertaining to gear boxes.



Any gear case I have ever seen that is filled beyond what is considered a normal level (either by accident, or intentional) causes emulsion (foaming). This always causes higher temperatures, and premature gear wear.



The higher temperatures that all of you are experiencing are from emulsion. I as AH64ID states am one of the "By The Book" people. I have 98K on mine with no problems. I only tow 10K, but run my lashup every summer from So Cal to northwest Washington state every summer non stop 22 hours without ever shutting down my motor.



Maybe mine is about ready to fail who knows.



Mac

 

[Kirwin]

My NV5600 temperatures

Well, I'll add my experience. I've had two NV5600s with temperature probes installed. One has a fast cooler on one side and the manual transmission filter from Genno's on the other side. The other one has only the manual transmission filter installed. I pull a 12K Holiday Rambler travel trailer with both trucks. I run the Mopar specified lubricant in both transmissions and they are filled to the level as specified in the service manual.



I see temperatures around 180-200 F routinely at 95 F ambient. On one trip in Texas with a 75 MPH speed limit, and ambient just over 100F, transmission temperature got above 260F, which is the highest temperature that my Cyberdyne digital gauge reads. Now understand that this happened over several hours. I was tracking it very closely. I have found that the NV 5600 temperature runs very close to engine ambient when pulling, this takes several hours at interstate speeds to achieve. As soon as you slow down temperature falls off in just a few minutes.

On another topic the rear differential is also quite warm when towing and it seems to warm up faster than the transmission. It is also very sensitive to hill climbing when pulling. I've seen it over 220 F when climbing, normally it's about 180-190 F. Its temperature reaches equilibrium faster. I am running a Mag-Hytec rear cover.

The transfer case runs around 140-160 F. about 60 F less than the transmission. My transfer case drain plug is fitted with the sensor.

My $0. 02. Ken Irwin

 

[Prairie Dog]

Very interesting info Kirwin, 260 would concern me and if I towed heavier, I would have a temp gage for sure.

 

[AH64ID]

Kirwin, do you see different temps from the fast cooler truck to the non fast cooler truck?



I am doing to mods to the truck this spring and one of them is going to be to wrap the exhaust down past the xcase to keep heat away from the trans/xcase while towing hard.

 

[steved]

The higher temperatures that all of you are experiencing are from emulsion.



Mac

Its not foaming in my case, I already checked for that several times... the oil contains no air bubbles when checked within 30 seconds of driving for several hours. I run either Reldine MTL (straight) or a blend of Redline MTL and MT-90 (1 quart of MT-90 and remainder MTL).



I just rolled 242k. Only part of those miles was run significantly overfilled. I overfill by a quart now, but I also run FastCoolers which make the added volume less than adding a quart to a stock trans.