NV4500 no 5th gear

been a while since I started a new topic but here goes, My 99 2500 with NV4500 lost 5th gear yesterday at 236K
so it sounds like the sliding gear nut has come loose. When I had the origional Trans fail from Lube issue at about 165K I found a new in the MOPAR box trans on line and received it and put it in and on the packing in the box I found a small card saying "5th Gear Mod" so I assumed that keeper nut collar had been done. So my question since it has been so long since I have been in to one is what is the best sliding collar nut fix that is still available? I am planning on pulling the transfer case as it has a small leak from between the case halves and I have the new gaskets and seals for that so I think I can pull the cover from the 5th/reverse area while trans is still in the truck after draining lube and put the 5th gear nut fix on and re-assemble????? Any information would be appreciated!!
gtwitch in wyoming

 

Take your pick of repair kits, here:

https://torqueking.com/category/5th-gear-kits-1994-2002-dodge-nv4500hd/

There is a ton of tech. info on the subject, just click on the links provided. I do advise you torque the nut to 400 ft. lbs v/s the FSM @ 280.

 

I installed a modified 5th gear and retaining nut in my first NV4500. Worked really well. Yes, you can do it without removing the transmission.

 

I tried a fifth gear retainer and it doesn’t keep the nut from still working loose and let the gear move just enough to ruin the main shaft gear . The best thing I’ve found is the nut with the brass lugs that go across the entire width of the nut then green loctite on the gear the shaft and the nut and then tighten the nut as tight as it will go

 

SA, Where did you get the nut with the brass lugs?

Thanks for al the input here! I downloaded the link above from Torque King and I have been to their place in Montana when it was in Roberts and talked with Dan and have bought several gaskets sets and other items. They are great folks and sorry to see them discontinue the full kit with the new full splined shaft but after reading the whole 10 page download I can see why as the NV4500 was a possible poor design as it evolved from a four speed transmission and it worked OK for lower torque gassers but when put behind the 5.9 Cummins, the torque and harmonics got to it, so we do what we can to keep it going for another few years!!

 

I used to get them through Allstate’s gear in Texas you have to specify the nit with the big Brass lugs not the one with the three round pucks

 

https://www.allstategear.com/NV4500-Main-Shaft-Super-Nut-Kit-p/nv27133.htm
I green loctite the bore of the gear the shaft splines the bore off the nut the brass lugs and the set screws and let the hole thing set overnight if you have the split washers on your shaft with metal ring I loctite that too

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I used a kit from Torque King that included a new 5th gear with more spline area and a double locknut setup. It even came with the tools and loctite formulas. Great kit! It worked well until I completely disintegrated 5th gear!
I then went to Standard transmission in Texas and got a complete rebuilt unit with the fully splined mainshaft. So far, so good.............

 

I have used the fully splined main shaft before it still won’t hold . The one quad 4x4 sells will work with the double but he has thats the way to fix it for good but I have good success with the super nut and gobs of green loctite the shaft that has the split washer with the ring that holds it in place is also very good . It Is also a good idea to not tow heavy in 5th I tow empty or up to about 20,000 using fifth but when I put a load on it stays in 4th

 

Correction, it was the Quad 4X4 version I used. Couldn't remember the name..................

 

Quad 4X4 is now Torque King, "Dan the Gear Man" backed out and family took over and moved to Billings form Roberts MT. I was on a trip about 10 years or so to Canada skiing and stopped to get parts in Roberts and had a nice visit with Dan and was impressed with his running of Quad 4X4 and later have bought from them and now Torque King a number of times!! Thanks Dan and family!!
gtwitch in wyoming

 

I have had 2 fifth gear failures in my 96 3500 4x4 in 20 years. First time in 02. New gear and upgraded Mopar retainer. Fat forward to 2014 and it drops off again. Gear still had to be tapped onto shaft and i reused retainer with new lock screw. I also added the fifthgearrepair.com kit and so far everything is fine.