I can get my NV5600 to shift if i am creative enough but it always wants to grind on upshifts. Notably worse between 1st and 2nd, 2nd and 3rd, 4th and 5th. 6th has never ground on me, and rarely a 3rd to 4th shift will. It never grinds on downshifts though. Also there is a rattling sound when idling second, usually when i am turning slow speed through a parking lot...but no rattling when accelerating while going straight. I am positive the sound is coming from the transmission. Any clues? :confused:

Sounds like its time to pull back that transmission at look at the clutch assembly. Grinding gear is usually cause by a clutch that not dis-engaging or a polit bearing that is going bad on you. Now if it only 1 gear that grind it would be a syncro for thaty gear...But I'm not a Tranny guy... But this is the little tidbit I can give...

I kind of feared that. I don't have much of a work area at the moment that this truck really fits in and I have heard that this transmission is around 300-400#. I am going to try changing the fluid in the transmission and hope for the best. Hopefully if fluid doesnt cure it a new clutch kit, slace, and master will. I suppose if this trans is shot I might swap out to the nv4500 since this nv5600 is an early model as far as I know. I can't find parts for the early models. It's just so odd that it's only upshifts.

Well fluid changes are always welcomed... When you do take the PTO plate off and mop out as much fluid as you can. Make sure you use the proper fluid back in the transmission too.

Have you owned this truck since new????? Is it the original clutch/tranny?? You are correct, the NV5600 is a beast and weighs about 450lbs. It is a truck tranny and is not made to shift fast or speed shift. You need to shift almost like you're driving a big rig.......slow and deliberate to let the synchros do there job. However, these trannys are known to be somewhat tempermental. Could be your hydraulics going out also.

I purchased the truck with 203k on it. I have no previous knowledge of the clutch or transmission on it other than what i can see by looking at it.

I purchased the truck with 203k on it. I have no previous knowledge of the clutch or transmission on it other than what i can see by looking at it.

when you stick it in first while at dead stop do you feel a drivetrain jolt? or, perhaps the truck will even start to move w/ clutch pedal to floor, and in gear? or hard to take out of gear when shifting?. . . this would be indicative of a clutch not fully disengaging. which would cause your symptoms. your clutch may not be disengaging completely, but with that many miles it could be time for a synchro/bearing rebuild. upshifting and downshifting use different "sides" of the synchro teeth, and since your tranny has undoubtedly seen thousands upon thousands more upshifts than downshifts, it is possible that you only experience the problem on an upshift. . .also you may have chunks comin off of your synchros hence the rattle. i think your best bet is drainin' tranny fluid into a nice clean container, and check it out for metal chunks/large flakes. if you have any chunks i'd be willing to bet that it's time for synchro/bearing rebuild. if there are no chunks or the metal is minimal, move on to clutch inspection. if clutch is ok then it's time to crack the tranny open. good luck.

I can get my NV5600 to shift if i am creative enough but it always wants to grind on upshifts. Notably worse between 1st and 2nd, 2nd and 3rd, 4th and 5th. 6th has never ground on me, and rarely a 3rd to 4th shift will. It never grinds on downshifts though. Also there is a rattling sound when idling second, usually when i am turning slow speed through a parking lot...but no rattling when accelerating while going straight. I am positive the sound is coming from the transmission. Any clues? :confused:

My wife's truck does this between 3rd and 4th if you try to shift directly from 3rd to 4th without a momentary pause. I drained the transmission and overfilled it about a quart or so with Pennzoil Synchromesh. A drain and fill is way cheaper than a rebuild. Try changing the trans. oil and over fill a quart and see what happens. It took a few days of driving my wife's truck after the oil change but it seemed to help improve the shifting. Its not perfect but it is noticably better.

when you stick it in first while at dead stop do you feel a drivetrain jolt? or, perhaps the truck will even start to move w/ clutch pedal to floor, and in gear? or hard to take out of gear when shifting?. . . this would be indicative of a clutch not fully disengaging. which would cause your symptoms. your clutch may not be disengaging completely, but with that many miles it could be time for a synchro/bearing rebuild. upshifting and downshifting use different "sides" of the synchro teeth, and since your tranny has undoubtedly seen thousands upon thousands more upshifts than downshifts, it is possible that you only experience the problem on an upshift. . .also you may have chunks comin off of your synchros hence the rattle. i think your best bet is drainin' tranny fluid into a nice clean container, and check it out for metal chunks/large flakes. if you have any chunks i'd be willing to bet that it's time for synchro/bearing rebuild. if there are no chunks or the metal is minimal, move on to clutch inspection. if clutch is ok then it's time to crack the tranny open. good luck.

The clutch "feels" fine while driving. Still grips and doesn't slip even with the Edge turned up. First doesn't cause a jolt at all, however it is hard to get it into gear sometimes. This goes for all the gears, however putting it in neutral and letting the clutch out then putting the clutch back in will let you get it into the gear. This is only while stopped though. It will go into the next gear without a feel if you know how to get it to go, it just won't shift straight in like it should.

My wife's truck does this between 3rd and 4th if you try to shift directly from 3rd to 4th without a momentary pause. I drained the transmission and overfilled it about a quart or so with Pennzoil Synchromesh. A drain and fill is way cheaper than a rebuild. Try changing the trans. oil and over fill a quart and see what happens. It took a few days of driving my wife's truck after the oil change but it seemed to help improve the shifting. Its not perfect but it is noticably better.

I am getting ready to change the fluid, if for no more a reason to forestall the rebuild a little longer till i have the money, space, and time. If the transmission is an older unit, which i believe it is i might end up replacing it altogether. I heard that 2000.5 got the improved NV5600. However since mine has made it this far maybe it is the better of the two lol.

http://dodgeforum.com/forum/dodge-cummins-diesel/112548-diy-transmission-work-nv5600.html Found this if anyone is interested on how to get into to one of these beasts of a transmission. Doesn't look that bad if you have the right equip. :thumbsup

http://dodgeforum.com/forum/dodge-cummins-diesel/112548-diy-transmission-work-nv5600.html Found this if anyone is interested on how to get into to one of these beasts of a transmission. Doesn't look that bad if you have the right equip. :thumbsup

Holy cow that is one for the books... I would love to have that whole write up here... Wow! :wow 8|

your synchros sound like they are grabbing. "flick" third before you put it into first and it should go right on in. same goes for reverse, flick third then hit reverse this will make your synchros line up better to put into the harder gears. first and reverse are the hardest gears to get into because of the nature of innards and synchro function, this should help ya out.

Or double clutch it... That also works too... I've driven a lot of old non-syncro fire trucks and water tenders...

Well it appears that the cost of rebuilding despite the parts needed may actually be worth it over replacing the unit. More so when you figure the hassle of returning a core charge mail order.However this is what i have found so far. The newer models supposedly require a spacer for the starter, however i can find no mention of this in the swap kits they sell for converting from the NV4500 to the NV5600 even though they are using the revised transmission. The only way to tell that i can find is to look at the top of the transmission for DEE which means its revised, or DEA which means its an early model.If the transmission is a pre-revision model then i will have to purchase:Bearing Overhaul Kit with Synchros26-tooth Input Shaft 1 3/4"40-tooth Late-Style 1st Gear39-tooth Late-Style 2nd Gear28-tooth Late-Style 3rd Gear25-tooth Late-Style on Cluster 5th Gear57-Tooth Late-Style on Cluster 6th GearLate-Style Reverse GearJust to complete the transmission to the new style it would be around $2000, however i am looking for some lower prices as i got these from Drivetrain.com.I would also need a new pressure plate and clutch. After market this would add at least another $1000-$2000 depending on the setup. So its getting expensive quick. Really i don't race or pull excessively with my truck i have even been thinking about converting it to a SRW for better ride and mileage so a Hays replacement clutch around $500 may just cut it for me.

That's the thing about Transmission parts as soon as you get into it the part as spendy...

Well it looks like the secret formula people have found is overfilling by 1 quart with Pennzoil Synchromesh or GM Synchromesh and adding a pint of limited slip. It sounds somewhat ok on paper, but i am wondering if the better route would be to buy the GM Synchromesh with friction modifier part no. 12377916. I think i am going to give it a shot if its not too expensive at the GM dealership down the street, otherwise if it is i may just go with the limited slip as the Dodge mechanics have recommended this in the past.

Well the overfill part has been suggested a for a few tranny I know of because of not getting enough oil to lube input shaft bearings and such. As for the mixture of oils and limited slip... Lets see how it works for you...

Well i put 6 quarts of Redline MTL in her tonight. The old stuff looked like hot cocoa and smelled like burnt ATF. I took it on a drive and it felt a little less notchy but and but third is still picky. I guess i will see if things smooth out over the next few days, since after all i changed the fluid in 35* weather so everything was cold when i was driving the short trip that i did.I have never noticed it before because i usually rest my arm on the center console (back of seat) but when shifting i had my hand resting on the shifter for a moment in 2nd and it felt like it was wobbling?I am wondering if this thing is just absolutely shot.

Well I hate to say it but I don't thinkg you got everything out of it. Did you open up the PTO cover and mop up the left over fluid looking for debris???

Yeah i took the drivers side pto cover off and cleaned up in there and resealed it with silicone. I will see if it smooths out any today since it is warmer. This thing has always been tough to shift in the cold. There really wasn't much in the transmission besides nasty tar like fluid and a few metal flakes. My Dakota had more metal in it than this thing and it shifts perfectly.