On the way back across contry 5th gear made some terrible noises and stoped working. I called a dealer and he said i could get home in 4th as long as i did not go over 55 mph. So that is what i did.

Now i hear there may have been some kind of defect in the 5th gear of the model??

Any info would help as it still does not work and want to make sure I get fixed what needs to be, and if it is some how coverd by dodge so much the better.

Thanks. )

 

This is truth and pretty EZ to fix ..pull the tail shaft and replace whimpy nut with new and better nut. END OF PROBLEM(for most)

 

Thanks for your reply. I thought that nut problem was gone with the 2001 3500s.

1) Not to sound stupid but do you have to take the tranny all the way out to do this?

2) What will prevent it from doing this agin???

3) will it also mean a new gear?

4) Will it need some kind of new sync gear?

thanks the wind.

 

If its 4wd of course pull the t.case, then just the tailshaft .the nut is a weak point and they make a newer improved one.(I have even herd of the nut being tac welded in a couple of spots,-make sure you unhook the batt.) So thats about all you need unless thy come up with a newer version??

 

I also have a 5 spd and I worry about the 5th gear problem, too. What has happened is 5th gear is not located with the rest of the gears internally on this tranny. It sits by itself and the gear shaft isnt supported but on one side. The shaft also isnt fully splined and the engine lugging pulses of the Cummins can vibrate the nut loose causing the gear to back away and stop working. Theres are a few other reasons but thats the basics. There is supposedly a few ways to keep it from happening. Dont lug in 5th gear by keeping rpms up around 2000 and dont tow in 5th. If you must tow in 5th then keep the rpms up around 2000 and higher. There are two ways to fix it if it goes bad, too. You can go back to Dodge and they can replace the orginal gear nut with a better locking one or you can take out the tranny and have the whole shaft replaced with a fully splined shaft. The last fix is supposed to be permanent but requires total tranny disassembly. Some guys have good luck with the new nut, some dont. Some guys have never had a 5th gear problem. Not really sure what the secret is, some think its the tolerances in the tranny apon assembly. Good luck.

 

Only the splined shaft will stop the 5th gear from moving back and not meshing, like it has been mentioned 5th gear is outside the cast iron case and the locking nut versions 1-5 may not be enough to hold the gear on. The full splined shaft is not that expensive it is just a lot of work to put it in especially a 4x4, converting to a 6 speed is a solution but expensive and work intensive. If 5th gear had been a straight cut gear all the torque would be transferred vertically, seeing as it is bevelled when excess torque is applied it also applies horizontal torque which in turn tries to push the gear off the shaft. The torque values the little Cummins generates sometimes exceed what the nut can hold ie: max torque 1600-2000 rpm in any version. We have also experienced the large thick torque washer behind the nut splitting and going down through the tranny causing damage. There also guy's with 400+ HP who have not experienced any problems towing, driver technique I would say is the key. The updated nut is not perfect as it is a split nut with an allen cap screw to be tightened, if the install procedure is not exactly right the nut may not make 100% thread contact on the shaft and won't hold. We had to spot weld one nut to stop it from moving, this creates a soft spot on the output shaft. PK

 

when you say convert to a 6 spd.-do you mean my preasent trany could be redone??

 

Some of the guy's are taking the NV4500 out and buying the NV5600 6spd and updating.You will need all the corresponding parts and a bigger tranny jack as it weighs 360lbs. PK

 

that was my question do I have to get a hole new tranny????getting it out is not the problem -I belive there might be a $$$$ issue here if a whole new trans is involved.?
Clue Me In EVVVVVEN

 

Yes Thumper the only way is to spend the $$$$ to get a trans that is bigger and rated for more torque. Without being a master machinest the NV 4500 is still basically a 4spd with a 5th over tacked onto the backend. The NV5600 is engineered properly with all the gears inside the cast iron case and bigger bearings. Other trannies will fit behind the B5.9 but will not fit under the Dodge cab or between the frame rails. For some old truckers a 9 or 10 speed would be real nice but the race oriented boys would hate a non-synchro counter shaft transmission. I have seen some talk of converting to Roadrangers but no pictures. Personally a RR tranny with overdrive would be great, 400 rpm splits and no clutch worries from over torque. PK

 

For all those who feel the 6 spd is superior over the 5spd, you must take into account that the 6 speed has had its fair share of troubles. It's not bullet proof. I just think its gotten more attention to fix the problems since its going to stay where as the 5 spd is no longer available. If the 5 spd was fitted with a fully splined shaft, straight cut teeth, or even a reverse thread on the shaft then we probably would have heard of a lot less 5th gear problems. The 5 spd is prefered for around tow driving, where the 6 spd is harder to shift. For towing I could see where the 6 spd would be better because of the extra gear. If I get a new truck I will be happy to have a new 6 spd, but I still like my 5 spd.