Clayten

c25 you can also go into what is known as spray arc. It can only be used on the flat position. To go into spray arc you have a higher voltage setting. The wire is already molten before it hits the parent metal. The real telling sign that you are at that stage is you get a whistling sound as you weld. Keep a bit of stick out at this voltage it is very easy to put your cup into the puddle and screw it up.

Valv

I used my old reliable miller arc welder with a bad fan, set it up to 105 and BZZZZT, BZZZZT, BZZZZT, 3 spots, that's it.
I had some creosote/ceramic C4 coated rods, but I thought they were a little too strong, so I used the old reliable manganese/plutonium 88 gold plated with glass filling.

I think she ain't gonna move....

Scramblinman

Since your signature indicates that you have a 2WD, the toughest thing for you will probably be breaking the nut for the u-joint yolk lose. I busted a 2WD one lose with a large 3/4" drive ratchet, but that was with the transmission strapped to a work table with the top cover removed and the transmission shifted into two gears at the same time to keep the mainshaft from turning. Doing it in the truck, you'll have to find some way of keeping the transmission from turning as you break that nut lose.

TIMMY22

The object of the weld is to lock the nut to the shaft so I can't back off. The nut and the threads are actually taking all the strain, the weld is just to prevent the nut from turning/moving.

If you were actually joining the gear to the shaft, you would be correct.

Scramblinman

There are some very good articles on Quad4x4.com about the whole NV4500 5th gear issue.

Clayten

Yes I understand that but. Once a crack starts in a highly stressed environment they tend to grow.( wire feeds with just straight wire/gas are notorious for this) For example, working on high pressure piping, even a stray arc from a welding rod on the pipe will bring about a cut out and replacement of that area. This is because of microscopic cracking. Any way usually by the time I am this far into a welding topic, I am well over half way through the fourth or fifth tall glass.

Scramblinman

I do not believe that the 5th gear nut qualifies as a highly stressed environment. It just needs to be prevented from backing off, not blown off the shaft by some highly pressurized or explosive force.

Clayten

Well I might think that any thing getting 600 + lbs of torque should qualify. But the vibration is the real kicker. Or should I say the real cracker. And it is not the nut that will crack but the shaft, and being as how it already on threads, just like notching a piece of wood to split.

TIMMY22

the biggest issue with welding the nut is you're adding metal/weight in one spot.

this can cause an out of balance problem on the shaft. That may lead to vibration and or excessive wear on bearings etc.

If it were me, I'd weld it just like Box5 did. You can't always follow the book on everything.

Clayten

I liked what Forrest brought up, Put on 2 nuts tighten and weld the nuts together.

Box5

yea, I was gonna leave just one little bead, but thought it'd help to balance out by laying the same size one on the opposite side. I'm no experienced welder, but I think it's alot stronger than just the nut sitting on the threads.

Scramblinman

I think that if anything lets go it would be the weld itself. So what. Arguing the semantics and academics of welding in this application is pretty much pointless. It's not like this has not been done before. If the job is going to done the absolute correct way, you might as well forget welding altogether. Locking nuts, double nuts, triple nuts, welding, whatever, they are all just band aids that do not address the real problem: The fact that 5th gear is not properly supported. Now matter how the nut is secured from backing off, the splines will eventually wear and allow the 5th gear to wobble, eventually accelerating wear and ultimately resulting in a trashed and probably broken mainshaft. A fully splined mainshaft is the ONLY way to correct the actual problem.

I think Box5's fix will do just fine for what it is. It will more than likely last for the remaining life of the transmission at which point the more proper fix can be employed during a full rebuild.

Box5

yep ^, case closed lol.

but anyone have any info on the oil, should I be fine just filling it up with the clear mopar stuff I bought?

Clayten

I totally agree with you, on the end result. But I was not trying to argue, I was just trying to bring experience and knowledge to the table. And that this could possibly lead to a path in the right direction in the future when this type of band aid has to be applied. As I stated in earlier posts, I would usually have this type of discussion with tall glasses and high percentages in the glasses. All to be taken with a grain of salt.

Bluetick

With that much thread showing on the shaft. I would be tempted to buy another nut mill it down and use it as a thin jam nut. If it would clear the housing.