Engine/Transmission (1998.5 - 2002) NV5600 Blown for the Second Time!

[J Trade]

Just blew my second Six speed! I have a 2001 Dually with the NV5600. About 8 months ago at 121000 miles, I had the transmission rebuilt including a new 6th gear set which cost me $2500. The shop was a reputable shop and seemed to do good work.



Well. . I was down in MS on I-10 cruising along at about 70mph, and the darn thing locked up again! I was not pulling anything either! I honestly thought I lost the front wheel it hit so hard! The truck now has about 130k on it. It is stuck in gear, if you let the clutch out the engine dies. The gear shift moves, but nothing happens. No leaks of any kind. I had to drop the drive shaft to move it.



The transmission shop has agreed to make good on the problem, the question I have is, are there parts out there that are better than factory parts? What transmission fluid should I run? Is there something they need to look for or check out that is a problem area? Is it possible they put the wrong transmission fluid in?



I buy and sell boats, so pulling 5-15k is very common, but mostly highway miles. I don't typically back boats in the water with this truck. I installed a Edge Comp box about a month ago (along with pyro & boost gauges) and run on level two. Clutch has never slipped pulling, put a new LUK clutch / Pressure plate when the transmission was rebuilt back in March this year. Honestly don't think the chip has affected the transmission in any way. This truck is not abused!



I need some guidance. I want the job done right this time. I really like my truck, and don't even want to think about getting a new one, but I want it to last, and I don't want to get stuck again 400 miles from home! By the way the truck is still in MS, working on a way to get it back to Atlanta, GA.



The NV5600 seems to be a reliable transmission, at least there are not a lot of threads posted with problems. What gives?!?!?

 

[Sageair]

I believe yours is actually the first post I ever read about a 5600 failure. I hope you have luck in fixing it for good.

 

[BJMarshall]

Hey man shoot me a PM and I'll give you my number. I'm in MS and could probably help you get it home. I've got a shop at my house and access to a big gooseneck. Could bring it here and pull the trans, or could help you get it back to GA.

Barry

 

[Phillipe]

greetings from the wilds of western co.



believe your problem is the 6th gear runs dry.

believe it is in the back of the trans.

try over filling the trans and use sys oil.

 

[J Trade]

Wonder if adding a fast cooler with the ability of adding more transmission fluid would help??

 

[COWBOYDUALLY]

Damn man thats hard luck, my dad has logged 356,000 miles on his 2001 dually. he has used his 1 ton for hotshot trucking since the day he has bought it. ive personaly seen oversized loads pulled on his 48 ft minifloat. we pulled his transmission for a checkup and sent it off to his buddy to have a look at it and he was thrilled to see that it has held up so well to the torqe that the cummins has trown at it. thats one of the reasons i purchased my 2002 dually 6 speeder. you cant kill them PERIOD!!!!! as for you the case of bad luck strikes and it doesnt sound like manufacturer error. What type of fluid was in it during the lockup casualty? my old man put in synthetic, it was a heavy oil but dont quit remember what it was(i will get back to you on that). with the weight you pull heat wouldnt be the big issue either unless it was to low for the assembly to sling the oil up into the rotating mass. i really hope you nail this problem! like Phillipe said try to over fill the transmission. Have you thought of the Fast Cooler? it holds more fluid!!!!and ive been pleased with it so far!!!! Jeremy

 

[J Trade]

The more I think about it, this may be a fluid level thing. I had the fluid changed at 98000 miles with Mopar fluid. About 20000 miles after that it blew the first time. The sceond time it blew it had 10000 more miles on it. I am not sure what type of fluid they used the second time, but it is worth asking. I know there are a ton of posts out there with transmission fluid types, but should I go back with the Mopar fluid or go with a synthetic like Red Line or Amsoil???



Still need a good parts source for transmission parts, or should I go back to Dodge?!?

 

[JKinney]

Mine has 50,00 on it and the fluid has been changed twice the last time was 20,000 miles ago, I just pulled the plug and fluid ran out so it must be full?

 

[COWBOYDUALLY]

JTrade,

man if i was you i would definitly investigate the type that they put in the transmission, its something that you need to know and when they tell you what type it was look at the jug and read to see what characteristics the oil has.

what type of oil should you use? well it goes back to what works and has worked for many years that has been PROVEN to work, i myself i your situation would go with a med-heavy synthetic. if you go with factory fluid,sure its in all the trucks new and yes people who are not maintence freaks like us will go 150,000 without changing it or God forbid even checking it!!!! the type of fluid from the factory is chosen for use in all climates in the USA. its lubricating characteristics are meant for cold and warm weather. but when you start putting heavy loads on it lubricates to a point then heat becomes a big issue with the factory stuff. ive had no problem with my factory fluid in the transmission but when initial break in was done i dropped that stuff and put in the good heavy synthetic. your going to have alot of people tell you to run this and that and preference is up to you but always at the end the facts will come out and you will better understand what is needed for your application, keep browsing the TDR site and probably you will find the guys who are experts at this issue and they will be glad to tell you what you need to know Jeremy

 

[J Trade]

I think we may be on to something here. Does it sound reasonable that there was not enough fluid getting up to 6th gear! Or would the wrong fluid casue the damage!



When it went out the second time, the truck was only running for about 20 minutes and under no load. Although the previous couple of days I was pulling about a 6k enclosed gooseneck trailer for 400 miles.

 

[COWBOYDUALLY]

yea i think your right! im in Bahrain Saudi arabia,(US Navy) i was able to call back to TX a little bit ago to talk to some of my Cummins friends and yes if the fluid isnt at a correct level this will cause damage of coarse. when the transmission is filled at the factory the oil is filled from the top of the transmittion. therefore when you first purchased your Cummins if you have ever checked it after you bought it it would drain out of the fill hole RAPIDLY. I was told to tell you that a excelent common practice is to be sure to fill as much as you can(with in reasoning,you know dont fill to much). if it is to full the rear seal in the transmission has a weep hole which can tell you two things #1 youve filled it to much and #2 the back seal is about to take a crap. the fluid situation on the other hand how much did the people put in ? did they just fill it to where their finger can just touch it or what? was it on level ground? i was told by my buddy that yes it can make a big differents!!! the 6th gear would go out with improper lubrication! damn i really wish i was back in the states i could explain it a little better :-laf the type of lubrication is the next factor and if i could only remember to ask it would be a bigger help for you!!! GO SYNTHETIC!!! and a name brand,once you get the beast rebuilt again you yourself watch the fluid being added and when YOUR comfortable with the level let it sit and idle for 2-4 min,check level again and so on until there is no drop in level. make sure to over fill a bit that way you know fluid is being displaced properly to the components that need it. its a damn shame to see these 6 speeds have a problem and this really doesnt mean that its a faulty transmission,stick with your guns and im sure you will find the problem,hopefully we have solved it or else i sounded like a rambling fool :-laf Jeremy

 

[J Trade]

When they rebuilt it the first time, I wasnlt trhere to watch them put in the fluid. I gurantee I will be there this time though!!! I will probably have to buy the fluid myself, since they will probably only put in a factory fluid or compatible, but I am OK with that. So you are saying fill the transmission from the top until it comes out the weephople??? Where is that located so I can get a visual here.

Thanx!

 

[COWBOYDUALLY]

no dont fill it untill it comes out of the weep hole,that is there incase it is to high or the seal is going out. when you pour the fluid in and it gets to the toplet the fluid sit for a minute or to and watch it them when it has stopped comming out of the fill hole put more in and try your heart out to cram more in without it going all over you and the transmittion. then put the screw the fill plug in and start for 2-3 minutes shut the truck down and just unscrew it until fluid bearly comes out then your at the spot.

 

[COWBOYDUALLY]

J Trade, i gotta go man and get back to my ship, we are getting underway in the Persian Gulf for a couple of days, i will check in periodically to see whats up,ill talk to you later... Jeremy

 

[J Trade]

Thanx Jeremy!

 

[J Trade]

Just found out the traqnsmission shop that did the work is out of business! Therefore I am totally screwed! Guess I need some reccomendations on used or rebuilt NV5600 trans. There is one on E-bay for $1500 plus ship, seems aweful cheap?!?! User id is kormextransmissions . Any suggestions?!?!?!