I fixed my 5th gear nut today. The previous nut was stripped smooth (it was the type with set screws). Mopar wanted $99.95 each for the nuts, and they had to order them and I HAVE to get my truck back on the road quickly, so I did not want to wait. I payed a visit to my machinist to have him make me two nuts (and a special wrench for them) so that I could stack them on the output shaft and weld them together. I don't see ever having to mess with another 5th gear nut on this truck.

The old nut:



One of the new nuts:



Both nuts on the shaft:



Final result. The nuts have 4 tack welds on them at 90 degree intervals:




Let me know what you guys think!

 

Nice!

Nice fix, very nice pics!

 

Awesome nice work

 

nice job always great to have a know a good machinest.

 

Nice simple fix. Maybe you could pass that along to the engineers of that design and hopefully the light would go on in their heads.

 

Wow, great fix!
So what were the specs on the bolts you had made?

 

Excellent idea! Good material will also help keep the nut threads from failing. Probably only took the machinist about 1 hour to whip that up and it looks great.

 

BTW, the nuts are made out of 4140 Chromolly. VERY strong stuff!!!

 

I'll be the sour grape. I'll bet it vibrates back off, just like the original, in less than 50k miles. The crux of the problem is that the entire spline inside the gear is not mated to the spline of the shaft and starts to wobble after awhile. The wobbling accelerates the wear on the splines to the point that no amount of tightening can keep it from vibrating loose. Hey, you wanted to know what we think.

 

Did you tighten the 2 nuts towards each other? Just curious.

 

Hey, no problem with stating your opinion, but I would like to offer a rebuttal none the less. It is physically impossible for the two nuts to come off together, so in order for it to vibrate loose once again the tacks have to break.

 

I agree I have yet to see a double nut back off. I have used double nutting in some real pain in the neck stuff.And with it welded that is one more feather in the not backing off hat.

 

I submit that by welding them together you have, in essence, made the assy one nut. I believe that if you put a wrench on the nut opposite the gear that they will come off together with a little more torque than was used to install them, thus it is physically possible for them to come off together.

 

I have not found that to be the fact, I can be proven wrong. What I have seen if the nuts come off it is because the shaft has broken.So that is the reason not to weld to the shaft.

 

Anything can come loose. But with a jam nut like that, you will be stretching the threads between the two nuts, making the torque to remove it much much greater. Looking at that design, on the inner nut, I would torque it up to spec, mark it where the key seat is in the shaft, broach a a keyway in the inner nut. Install the nut, insert a small key, then torque up the second nut, which will retain the key, and will be welded to the first nut. That looks like a nice marketable solution.