5th gear thread (fifth gear fix) NV4500 transmission
 

How many of you have fixed your 5th gear nut without welding it to the output shaft?
I'm thinking that installing the updated nut (which has two set screws) is a good idea.
With a good amount of the new permanent Loctite 263 on the output shaft and on the set screws. Anybody else think that should take care of it?

Has anybody seen the 5th gear fix by this company??
NV4500 Transmission 5th Gear Repair
They have some kind of special retainer, but I can't find any info on it???

Does anybody have the tool available to loan for a fee?
6743 is the number of the tool I need.

Don't like the idea of welding it... that can compromise the strength of the shaft.

Thanks!

my buddy bought the new gear and washer with the latest and greatest retention nut with set screws, he installed it all and with locktite too

6 months later when that one backed off too I told him to bring the truck to me

here is what I did to fix it and the truck is still on the road today

https://www.dieselbombers.com/dodge-...ining-nut.html

i myself have used two different fixes both updated nuts one was a new nut that was cut and had a set screw to clamp the two pieces together for a tight fit needless to say i didnt get much over 10k before i lost it again. My truck currently has the nut that your looking at in it with 30k on it and no problems.:tu:

I put mine on the first time but didn't get it tight enough nd lost fifth 5k miles later. I made a tool to install the nut but only made it another 200 miles before my engine grenaded. The key is to make it as tight at you can. Don't lug fifth gear it'll back right off.

I cut a piece of 1 1/2 pvc and slid it over the shaft to fill in the gap between the nut and the transfer case. That way the nut cant back off.

i always wondered why they never cut a left handed thread in the shaft that way it would be getting tighter as it rotated

This new loctite is supposed to be ultra strong for use on high vibration applications.
The nut is a solid design, with set screws, and brass pucks. The earlier design looks to be a two piece with set screws.

I may try to make one out of steel pipe.
One similar to this:
NV4500 Transmission 5th Gear Repair
Now THAT looks like a sure fire fix. It is held in place by the splines of the shaft, which makes it IMPOSSIBLE for the nut to back off.
100% solution but it is not super cheap.

I will probably use 263 loctite, one piece nut with set screws also 263 loctited, torqued to 300ft/lbs, then install the one piece nut retainer from that website.

the biggest problem I see when peeps do the set screws is they dont cowboy them up, for those that dont know this means there is a backer setscrew behind the first one that actually doing the setting, the second set screw holds the first one from backing out from vibs......the new nut has 2 holes for set screws 120* apart

That would be too easy, right! LOL
Manufacturers of engines and drivetrains always do things that make owners and mechanics scratch their heads... :humm:

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I pay close attention to detail and have been prone to overtightening fasteners. I don't know if anyone has ever stripped out one of these but I have honestly told myself I will torque it rather than going apesh!t and damaging something LOL.

A few thousand miles back my 4500 got a rebuild...:bat: Seems the guy that owned the truck before me fixed the 4500 by welding the nut in three places. I came off the light towing a Geo Metro of all things and therer was a big bang. A real big bang. No forward, no reverse, no 4wd...dead right there. Got it on the hoist and took it apart. The output shaft had sheared off clean at the welds. Darn near perfect clean cut. You could see the penetration well into the shaft. Ran it over to the T-shop and the brought her back to life with all new guts, top plate, and updated shaft and nut. I would have to say, keep the welder out of there.