On a warm day, they all get hot. On an 80 degree day running empty down the highway at 65-70, my 5600 will see temps around 170-180. Towing that same day will run it up to 200 and higher easily.

Running in 6th gear will make it run warmer than 5th gear will. Myself, when I tow heavy on warm days, I keep my eye on the trans temp and downshift and run 5th for awhile to bring the temps down when it gets a little warm.

How hot does yours get? I have seen mine at 220 as well as others I know of. Are you running the stock fill amount or over filled. It makes a big difference on temps.

Jeff

 

I'm running empty no load.70 -75 mph at 2400rpms.It gets hot.then hard to get in 2 and rev.stock fluid level with the chrysler trans. oil.
Ive read alot of problems with the nv5600.Do you know anything about High Gear Transmission in Memphis Tenn. or about changing the type of oil.

 

recalls are mainly for safety issues

 

Stock fluid level is not enough for these transmissions.

There is a oiling issue on a bearing in the rear of the transmission when running stock levels. It will get oil but not enough so you have to over fill it.

6 Quarts is the norm for an overfill. The easiest and for that matter the only way to get it all in there is to pull the shift tower off from inside the cab and pour it in the top. The over fill will take care of the oiling issue and provide it with plenty of lube.

Type of oil is personal preference I guess. The stock fill from the factory in my truck was dumped at about 20,000 miles and I have used either Redline MTL or Amsoil MTF. Out of the two, I prefer Amsoil. I find the trans shifts better for me anyways and seems to not make as much noise.

There are going to be guys on here that say the factory Mopar oil is all that should be in these transmissions. Using aftermarket oil, I'm over 200,000 miles on my pig and a good chunk of that is towing and the trans works and shifts better than new.

I would recommend a transmission temp gage, it's amazing how much heat these lumps will make in 6th gear compared to 5th. Just because you can pull a hill under load in 6th doesn't mean your not heating the trans up.

On flat land pulls, I've down shifted to 5th and run for upwards of 30 minutes to bring the temps down before eventually shifting back up to 6th.

Problems with these transmissions, sure there are. But the units with problems compared to the ones without is about the same as every other truck problem, some have them, some don't.

Jeff

 

thanks for the info,

 

"Some new info on the NV5600 after I had to have mine replaced! My trans guy is pretty well known for being an excellent mechanic and he let me in on a few points of interest re: the NV5600.

1. There is a modified case with an opening at the rear right lower corner that allows fluid to the rear gear. This occured around late 2000, this allows fluid to the back so these trans won't really benefit from an extra qt. Unfortunately you'd have to pull the transfer case to find out. If you don't know the extra qt can't hurt. Rebuilds have 2 or 3 1/2" holes drilled in this location if the rebuild shop is a competent one.

2. The wrong fluid is what kills the backing plates (synchro's) in these trans. It doesn't take a whole lot of driving to accomplish this. My new trans will run the Texaco/Chrysler fluid until the warranty is up, when I'll switch to the Amsoil version or the Redline. I haven't investigated enough yet to make a decision. The wrong fluid is usually put in at the local Quickie lube, the tech sees a big cast iron case and just assumes gear oil is the required lube.

3. Towing by the front end can mess up the backing plates in a hurry if the trans is in neutral and the driveline is in place. When towing these rigs, make sure the wrecker drops the drivelina at the rear end and straps the driveshaft up. I got a $45 bill for this and consider it very cheap for the headaches it could cause down the road if it reduces the useful life of my trans.

4. You own a truck that was made primarily for pulling a lot of weight. The more I have in mine the easier it shifts and the smoother everything is. A trailer increases this feeling even more. The trans is not meant for racing or flying thru the gears, it's big, heavy and almost bulletproof but needs a moment to line everything up before smoothly slipping into the next gear. When going from a stop or forward gear into reverse push toward the 'R' and count one, two, three and it should slip right in. Forcing it just causes stress on the internals.

5. My truck was purchased used w/53K miles on it and my past experiences w/ 1 tons and larger trucks made me notice the trans shifted kind of hard and toothy but from what I've read on here I assumed that was pretty normal...wrong! My new trans shifts very smoothly and I was very surprised the first time I drove it that I had been driving it the past 2 years with damaged internals.

By the way, My old trans was pretty much destroyed during disassembly, some of the components were so tight that a lot of heat and a huge press were needed to get it apart effectively rendering the main shaft useless. I was amazed at the size of the mainshaft in this trans and my trans guy said that I couldn't possibly break it but the wrong fluid is like cancer to these trannys. Good luck with yours!"
https://www.dieseltruckresource.com/d...0-t156149.html

 

I have had good luck with mine. I have about 135K on it with not 1 problem and only 1 clutch so far at about 80K. I don't tow anymore, but did for a few years tow a 10K race car trailer. I have always overfilled by 1.2 quarts and used the manual trans filter on the passenger side PTO cover. Make sure to put some teflon tape on the fill plug b/c with the extra capacity it will leak out some if you don't since the fluid level sits above the fill plug hole (I pour the fluid in through the shift tower inside). The PTO filter also increases capacity another .2 quarts or so. I also have changed the fluid every 30K-40K miles and use the Pennzoil Syncromesh fluid. I swore I would never purchase Pennzoil, but this is good inexpensive fluid. Most people are morons when it comes to this transmission including people that are paid to work on vehicles for a living. In fact the dealership that did my clutch (did a rear crank seal on warranty - I had them do the clutch at the same time) put in regular Dodge trans fluid. When I picked the truck up it shifted like crap, so I knew immediately what was wrong and changed it as soon as I got home. It then shifted like brand new. I also use 1st gear even when not towing as this seems easier on the drivetrain and clutch. I like the idea of adding a temp gauge, but since I don't tow currently I will hold off. These are very strong and reliable transmissions if you take care of them with fluid changes, overfiling, proper fluid use, and waiting a split second before shifting for all the big parts to line up. I still hear about people driving without a clutch and then they are the same ones that complain when they have to pay to fix the gearboxes.

 

I have an 02 3500 NV5600, about 60k. It drives and shifts like new. I tow my fiver and utility trailer, up to 14k. I have 4.10 gears, I am sure this helps with temps pulling heavy.
It sounds like that by 02, most improvements had been made and maybe running 1 qt over may be good, or possibly not needed. I plan on refilling with the Penzoil Synchromesh shortly.
Does this sound about right?

 

The way I have always looked at is that oil is cheap compared to a rebuild. Whether you run stock oil level or overfill, it's still better to change it often and do what you can to take care of the trans.

Jeff