Alright my question is this. I have a 2002 Dodge Cummins with the NV5600 Trans. It has a dual disc clutch in it, and the hydraulic upgrade. The trans had gotten to where it would grind alot and wouldn't down shift, so I put the hydraulics on it. Well now for whatever reason from time to time when I get in the truck after it has been sitting over night, it feels like the brakes are locked when I try to back up or pull up when first moving it for that day, but it frees up and goes on. What could this be? Also today, I have been pulling a gooseneck around with 6 tons on it. I unload the trailer and head home, pull up to a redlight and push in the clutch pedal, everything feels good, start to let the clutch out in first gear and the truck acts like the brakes are locked and it wont go, just jumps, so i do the usual trick to get it going, and pull it out of first, let the clutch out in neutral and try again. But today with the truck in neutral, I let the clutch out and it trys to choke down, what the crap? So I press the clutch back in, and the truck comes back to normal idle, push it in first and decide it is going to move or break, start letting the clutch out and building rpms, and when it gets almost out truck jumps and hops like the brakes are locked, or the trans is bound up. Once all this is done and it rolls off, it shifts perfect all the way home. It does this whether I am pulling or just driving with no load, but does not do it on regularly, just now and then, but often enough to be a problem. My question is what is causing this?!?

Sorry for the post being so long, I hope that I explained this good enough that it is understandable. Thanks for any and all help on this one!

 

Stop driving it, The nv5600 has a problem with the rear bearings on the output not getting enough oil and it will cause the tranny to sieze. Which in turn causes the bearing race that is pressed into the cast iron case to spin and tear the crap out of the case. If that happens you are shopping for a new case and they are pricey. So check the fluid in it, It should be above the fill plug, I always fill to full then add 1 qt through the shifter plate to stay safe.

 

Thanks, figured someone would know what the deal was, how do i check that rear bearing?

and it is parked for now!

 

I have a manual for it if you need.
Is it time to change the fluid out? How many miles on the oil and on the trans too? If you can drain it (Just pull one of the PTO covers / plates off the side of the trans. They are held on with 6 bolts (I think!) ). If it has any steel ground up inside in the bottom you may have a problem. A bit of brass flakes / small chunks are normal. They are from your synchros. Inside the PTO cover in the center of the trans is a magnet laying in there. This will help to grab and hang onto any ferrous metal in the oil.
Let us know what you find!
Dan

 

Well sorry for not getting back to this sooner, I took the truck to ProStreet Diesel last week, and hopefully will have it back this week. All the synchros were shot in it. Looked like the bearings were all still good, and gears were all good. While it is out he is going to put all new synchros in it, all new bearings, and new fluids, plus a set of Fast Coolers on it.

Was trying to decide if I wanted a short shifter in it also, but couldn't bring myself to put that money on it right now on top of all the other. Maybe later, what are others opinions on the short shifts for this trans, is it worth the money or just stick with it stock?

Well hope to have it back soon, and it should shift better.