NV5600 failures...heat related?

[steved]

After reading all the NV5600 failures as of late, I am considering getting Fast Coolers for mine...



I know they work to reduce heat (that's not what I'm asking), but are they really needed? I mean, these failures I have read about seem to be mechanical and not overheat related...



Is it actually going to help or is it $190 of shiny aluminum that does very little to prevent a failure??



EDIT: Oh and as a side note, overfilling my NV5600 by 3/4 quart made it shift worse and run hotter... using the same (but fresh) fluid. I'm going back to PZ Synchromesh and be done with it...



steved

 

[steved]

No one has an opinion on this huh?



I pulled the fill plug on my NV5600 tonight and drained the "overfill" oil out... took about a quart out... it is now even with the fill hole...



I am wondering if the oil is acting more like insulation... the transmission ran (when driving empty) at 230* in 85* ambient air when it should have been closer to 190*...



Another diesel head had the opinion that maybe the oil was so high that it was either foaming because it had submerged gears or possibly deep enough that it wasn't getting slung around (if the NV5600 relies on oil slinging for lubricating)...



I also was wondering if the added oil was "flooding" the sychros possibly causing my hard shifts again... drained the oil 3k ago, added the same oil (only new... using redline MTL) and the shifting has been stiff ever since... maybe if that top portion relies on slinging, the synchros weren't getting enough oil??



Thoughts??



IMO, if the NV5600 really needed to be overfilled, then why aren't we (this board) seeing more bearing failures because of oil starvation? Maybe it doesn't need overfilled?? Of course, how many people are actually running a temp guage to see a difference between a normal fill and quart+ fill...



Oh, I did buy the fast coolers today... as well as some Amsoil MTF to give that a try... if the MTF doesn't suit me very soon in the filling, then I'll resort back to the original Synchromesh...



steved

 

[GWBourne]

i have had my fast coolers for almost 2 years now... they are sitting in the box still... oops



been too busy to get them on. i plan on a temp sender when i do it all, and that is part of the problem as well. time and money... .

 

[Briman]

I've used pensoil SM for over 90K miles. Changed it three times and the trans shifts as good as it ever has. I did have a NV5600 failure when my truck was two weeks old, but that was because New Venture left some parts out of mine. I have run Red Line in another NV5600 and found no benefits whatsoever over the Pensoil. The pensoil is certainly less expensive. I have never overfilled either. I don't know what temp my trans is running, although I would like to monitor it. I do tow 10K lb once in a while, sometimes in summer in southwest heat. I've not been concerned because the trans has not made any unusual noises or shifted any different even under tough conditions. I am not inclined to spend almost $200 on aluminum extrusions.

 

[steved]

Well, this is sorta interesting:



I drive 50+ miles one way to work... this is my "test" run. A good portion of this is interstate with some "heavy traffic" areas (lots of shifting)...



Monday, the transmission was about 200* by the time I got to work... same temps (ambient air) outside as today... same type of driving.



Outside air temps make a significant difference in the readings on the transmission... typically, the hotter the outside air is, the hotter the transmission runs... however, they are not two parallel lines... there is more spread the hotter it gets outside... for instance, at 110*F outside, I should run around 230*F or about 120*F above ambient air. At 70*F outside, I normally run 150*F or about 80*F above ambient air. And it is very predictable knowing the trend.



The trip to Tennessee I took a month ago, it was 85*F outside and the transmission was running 230*F... that's how I knew something had changed!



Today, the transmission never broke 150*. I even ran 75mph and not my normal 65mph (so things were really cooking along with 4. 10 rears at 2500RPM)...



I also noticed within a couple blocks of the house that the transmission was shifting better... it goes into EVERY gear much easier, just like new fluid should feel. Before it was almost grinding 5th... it was hard to get into 2nd. And again, all I did was pull the fill plug and drain the excess oil out...



So, IMO, overfilling might not be such a good thing to do, regardless of whether the transmission shop tells you to do it or not... and I only got an extra quart at the most out, which IIRC, is all the extra I put in. And FYI, 50 miles only proves how much longer it is taking to heat up, it takes me several hundred miles to actually get it to "operating" temperatures, to the point it will stop climbing... but in this fixed distance and more or less fixed route/conditions... it is pretty clear the difference.



Hopefully I have the coolers by Friday... I'll install them this weekend and they will get tested in a week or so as I got a run to New Mexico at the end of this month...



As for not running coolers... I look at it two ways: Keeping the oil cooler will cause the oil to last longer and keep the seals happy (and generally with gearboxes: the cooler it runs, the longer it lasts), however, it might also keep the oil cool enough that it stays "thicker" and cost you fuel mileage at the same time... and again, how many owners are actually running with a temp guage in the transmission to know what is going on??



steved

 

[05mxdiesel]

Steve, thanks for all the info, what is your opinion on the filters for the 5600 that Geno's sells. They state they will not work with the fast coolers. Or is your thinking that heat is more of a killer than the small debris that the magnet won't catch? I was told by a few people to overfill it as well, but it shifts so smooth now that I am not even worried about it. Thanks

 

[steved]

Steve, thanks for all the info, what is your opinion on the filters for the 5600 that Geno's sells. They state they will not work with the fast coolers. Or is your thinking that heat is more of a killer than the small debris that the magnet won't catch? I was told by a few people to overfill it as well, but it shifts so smooth now that I am not even worried about it. Thanks

I'm not sure what to say about the filters... everytime I have drained my fluid it has been crystal clear... except the time I had the problem with the RP Synchromax. I sort of feel that if it is brass or aluminum floating around in there, it is softer than the material the bearings and gears are made of... that brass/aluminum should not hurt the hardened steel surfaces... the magnet will hopefully catch any iron particles that could potentially hurt the bearings/gears. I am currently running a better magnet than the one provided by DC/NVG... it comes out almost clean everytime.



I know the one thread I read about the filters showed that the filter does indeed work as it was completely covered with nasty looking stuff... and most guys that want to run the fast coolers AND the filter run a single fast cooler on one PTO opening and the filter on the other PTO opening...



I am also not sure about heat... how much is too much? What is "normal" for the NV5600? What is considered "hot"? I know the one oil I ran said it was stable to 400*F... so what's happening to it at 230*F?



After seeing the results of running my transmission overfilled and then running it full, I will not run it overfilled again. I would also expect that if starving bearings was an issue (running it at normal full) in the 5600, then we would hear of it happening more often??



steved

 

[05mxdiesel]

I'm not sure what to say about the filters... everytime I have drained my fluid it has been crystal clear... except the time I had the problem with the RP Synchromax. I sort of feel that if it is brass or aluminum floating around in there, it is softer than the material the bearings and gears are made of... that brass/aluminum should not hurt the hardened steel surfaces... the magnet will hopefully catch any iron particles that could potentially hurt the bearings/gears. I am currently running a better magnet than the one provided by DC/NVG... it comes out almost clean everytime.



I know the one thread I read about the filters showed that the filter does indeed work as it was completely covered with nasty looking stuff... and most guys that want to run the fast coolers AND the filter run a single fast cooler on one PTO opening and the filter on the other PTO opening...



I am also not sure about heat... how much is too much? What is "normal" for the NV5600? What is considered "hot"? I know the one oil I ran said it was stable to 400*F... so what's happening to it at 230*F?



After seeing the results of running my transmission overfilled and then running it full, I will not run it overfilled again. I would also expect that if starving bearings was an issue (running it at normal full) in the 5600, then we would hear of it happening more often??



steved

I agree with you on everything you said, but to really know what is going on inside the cases and the oil why not send a sample in. That way you know if the oil is being sheared down or oxidized from the high heat. With all the oil draining that you've been doing it sounds like an oil analysis could be the answer to your problem. Hell I am even curious to see what an analysis would like on it, but after three vehicles and a bike it gets expensive just to see how far you can extend oil chnages and see wear metals.

 

[steved]

I agree with you on everything you said, but to really know what is going on inside the cases and the oil why not send a sample in. That way you know if the oil is being sheared down or oxidized from the high heat. With all the oil draining that you've been doing it sounds like an oil analysis could be the answer to your problem. Hell I am even curious to see what an analysis would like on it, but after three vehicles and a bike it gets expensive just to see how far you can extend oil chnages and see wear metals.

First, I did have an oil analysis done on the BAD royal purple... it was "within specs" and they found nothing wrong with it. It was "chemically" the same as the sample they had pulled from that batch run... to bad I had to force the shifter in and out of gear... to me, obviously the oil analysis said one thing BUT what I was actually seeing was totally different... so why "waste" that money if they are going to tell me the oil is fine?



As for the redline and this most recent issue, if it was an oil problem then dropping the level down in the case should have done nothing...



The only reason I have changed oil so much is to flush out old oil when changing brands and when I had the problem with RP... to date this transmission has seen 8 different fills... most of which were in a 4k period.



steved

 

[Buffalo]

Steved,



I believe the picture of the filter with all the nasty stuff came from Quad 4X4. If memory serves me right, that filter was on a trans. that was destroying itself. The picture shows how much debris can occur. It was a mess!!!



I have installed on of the filters on my NV-5600 but, so far, I have not changed the gear oil so I have no idea how much "junk" the filter is collecting. I figured that having a filter on the trans. "can't hurt".



Joe F. (Buffalo)

 

[Buffalo]

Just another thought.



I would think that running a synthetic gear oil would handle the heat better than a conventional gear oil.



Joe F. (Buffalo)

 

[dgieson]

I have Fast coolers on my NV5600 took off 50* towing on a 90* day and I did not like to see my trans at 250* don't think the trans should be hotter then the engine. My diffs never have exceeded 170* under the same conditions. I think a lot of folks think the diffs will get hot and put on Mag hitech covers etc to get them cooler, but I don't see that as a problem. I have had one trans failure at 20k not heat related.

 

[ASchwartz]

I have had the fastcoolers on for over 60,000 miles and can not get the temps above the engine temp. They normally stay around 185*. IT does take awhile to get there though. I was running Amsoil 5w30, the same oil I run in the engine. It was a bit expensive so I switched to the amsoil syncromesh and noticed my temps were about 15-25* hotter with the Syncromesh, however, it does shift better.



Avi

 

[steved]

Buffalo:



I agree, any filter is better than no filter. I was unaware of the source of that picture, as I thought it was posted by one of the members of this site. IIRC, all synchromesh is supposed to be synthetic, although as we all know, there are varying degrees of synthetics and some are definately better than others...



dgieson:



I know what you are saying about the rear temps... After returning home from a 300 mile run I was under the truck with minutes checking something or other... while the trans was too hot to even begin to place my hand on, the rear was only very warm to the touch. Might be that there is more airflow around the diff (more open and just plain more air) and that the axletubes act as heat sinks to pull the heat away from the diff?? Either way, I'm sure the trans being sandwich in between the tcase and engine and stuffed up high in the frame doesn't help with cooling (being cast iron does't help much either).



ASchwartz:



When I install the coolers I'll be running Amsoil as well, although my transmission has never seen 250* (only ever maxed out at 230*) but I have not towed reall heavy either. I had heard of guys running 5w30 in the 5600 with good success... wonder what's different between it and the MTF??





As a followup, on the ride home yesterday outside was near 75* and the trans never got above 150* and shifting has significantly improved... so IME, overfilling might not be a good thing as I have shown in this thread.



steved

 

[BJMarshall]

The ZF's in the Fords have a small pump and an external cooler. System works real well to control temps, but will pump all the fluid out in short order if a line gets broken.

About a year ago I built a setup for a friend using a weldon pump, a cooler with a fan and a filter. I wish I had taken some pictures. I modified an oil pickup I think came off a Honda engine and attached it to the left PTO cover. The pickup went to the bottom of the transmission nearly in the center. Very little room so it was kind of tricky to fabricate. The pickup passed thrpugh the PTO cover and I welded a -8 male AN fitting there. I ran a hose from there to the pump, from the pump to the cooler, and from the cooler back to the rear of the transmission. I drilled and tapped the rear housing and had the cool return oil spray directly on 5th gear. I think he spent close to a grand on this setup. The pump was the most expensive part at about $500.

Transmission temps have dropped over 100 degrees. He wired the pump up to a toggle switch. We were going to put in a temperature switch, but never got around to it. I can't remember the exact numbers, but I believe the original temps were running around 260-270. With the pump and the fan running, the system will bring the temp down to about 30 to 40 degrees above the ambient air.

I think this setup would work great on a 5600. It also makes it extremely easy to change the fluid. :-laf

 

[steved]

The ZF's in the Fords have a small pump and an external cooler. System works real well to control temps, but will pump all the fluid out in short order if a line gets broken.

About a year ago I built a setup for a friend using a weldon pump, a cooler with a fan and a filter. I wish I had taken some pictures. I modified an oil pickup I think came off a Honda engine and attached it to the left PTO cover. The pickup went to the bottom of the transmission nearly in the center. Very little room so it was kind of tricky to fabricate. The pickup passed thrpugh the PTO cover and I welded a -8 male AN fitting there. I ran a hose from there to the pump, from the pump to the cooler, and from the cooler back to the rear of the transmission. I drilled and tapped the rear housing and had the cool return oil spray directly on 5th gear. I think he spent close to a grand on this setup. The pump was the most expensive part at about $500.

Transmission temps have dropped over 100 degrees. He wired the pump up to a toggle switch. We were going to put in a temperature switch, but never got around to it. I can't remember the exact numbers, but I believe the original temps were running around 260-270. With the pump and the fan running, the system will bring the temp down to about 30 to 40 degrees above the ambient air.

I think this setup would work great on a 5600. It also makes it extremely easy to change the fluid. :-laf

I thought about mounting a small 24V oil pump (it would still run on 12V, just slower), hydraulic filter, and cooler w/fan on this one... I have seen the surplus parts for under $200... probably should have done that and not the Fast Coolers... since the fluid sort of "floods" the cover... should have been as simple as installing everything (everything meaning the suction and return fittings) into one PTO cover... the 24V pump I was looking at was military surplus...



I was also contemplating buying my own piece of aluminum (a 2. 5" thick plate) and cutting my own crude coolers, but it would have cost me $80 for the aluminum alone, plus the cost of the blades, hole saws, etc... was almost as cheap to just buy them already made.



steved

 

[rbattelle]

I've had fastcoolers since roughly 25k miles. Unfortunately I don't have any temperature data. There are 2 things I like about them: 1) the clear lexan cover makes fluid level checks a 2-second process, and 2) the magnetic dipsticks can be removed anytime and ferritic debris removed.



They also look pretty cool... but I'm the only one who ever sees them.



Ryan

 

[dgieson]

One more thing going for the Fast Cooler over a pump system no moving parts and it still gets a 50* or more temp drop on the trans.

 

[steved]

One more thing going for the Fast Cooler over a pump system no moving parts and it still gets a 50* or more temp drop on the trans.

This was my thought exactly... that's the reason I never pusued that idea...



The coolers never showed, so it'll be a week or so before I get around to it... the transmission is running a lot cooler without being overfilled...



I did fix the fuel tank EVAP vent issue and adjust the valves today...



steved

 

[ASchwartz]

When I had my Dual Disk clutch installed, I asked the mechanic about overfilling and he said to never do that. With the extra fluid, cavitation starts and then you get hydraulic pressures that the transmission may not be able to withstand.



Avi