I just lost 5th gear in my 96 cummins 4x4 nv4500. I have an updated nut from dodge with 2 set screws. I made a 5th gear nut tool to tighten the nut to 300ft lbs with the water jet at work. My question is, has anyone been able to tighten the 5th gear nut without the spline socket to hold the shaft? The spline socket cost more than the 5th gear nut and cant justify buying it. Has anyone made their own or has another idea on how to stop the shaft from moving?

 

Yes, I stuck the truck in fifth gear and the stuck a rag between the gears as suggested by another member here, I got it 250 with my torque wrench the move it some more with a 3/4 drive ratchet and pipe.

 

If the trans is out, remove the shift top and put it in 2 gears. If the trans is still in the truck, slip the driveshaft back onto the splines and stick a pry bar through the yoke.

 

Can't do that if its 4wd

 

Hate to be bearer of bad news but the updated nut doesn't work any better. Looks at the smooth part just behind the splines. If you can see teeth marks the main shaft is shot and the 5th gear will just rock and break the nut again. Mine failed with the updated nut. Put a new on on with 2 tack welds and it made about 250 miles towing and broke again. You might look at a place called quad4x4 in montana i think. They have a solution if the tranny is still good.

 

the tranny is still in the truck. so i can just put rags in the gears? does anyone know the size of the output shaft, spline count, and spline width and depth? i could waterjet a socket at work. also where can i get a big enough torque wrench for 300 ft lbs?

 

if someone could also give me a picture of the shaft from the end showing the splines, that would be great also. i would just have to scan the picture to the waterjet and resize it to the size of the shaft.

 

OOOOPPPSSS!!! Didn't think that far.

 

Do yourself a favor if you plan on keeping the truck long.
There is only one fix that works long term, read about it here> http://quad4x4.com/Dodge%2094-04%20NV4500.htm

I tried the "improved nut", 20k later I had no 5th again.
Know several people who have had the same bad luck welding the nut to the shaft.
The problem isn't the nut or gear, it's the shaft they ride on.

 

Yep, the problem is worn splines on the shaft. I have replaced shafts in 2 trans where someone had welded the nut to the shaft and then the shaft broke In cases where the owner didn't want to spend the $$$ on a new shaft, I have welded the nut and washer to the gear, but never weld on the shaft.

 

what about to nut that goes over the splines of the shaft? i think a place in california makes it?

 

http://www.standardtransmission.com/dodge.html has fix that involves wedges but I know nothing else about it.
Standard Transmission is a top notch outfit, I'm certain whatever fix they sell works long term.

 

https://www.dieseltruckresource.com/...7&d=1286939317


That is what my old one looked like that wasn't fully splined and the fully splined is what is in my truck. I will probably regret some day not going with the quad4x4 set but for now it holding and I only 9k mile on the truck last year and only 2k since the rebuild. All towing of course.

 

why hasnt someone made the 5th gear threads LH yet? that would better

 

The problem isn't the nut or gear.
It's because the mainshaft isn't splined long enough.