Just lost 5th gear this morning. First suspected the clutch cause I had a South Bend CON OFE put in two weeks ago but realized I had all other gears.

I assume 5th nut slipped? I've had to change the seal at the driveshaft 3 times so does that mean I have a worn main shaft too???

Your opinion on where I should go from here?

 

Just went through this, since you are a 4X4, I would either recommend the updated mainshaft and the 5th gear nut retainer that is out, or if your shaft is still in good shape, the updated nut and the 5th gear nut retainer. I got mine from the company that sells them on Ebay, but there is another one out there as well

http://fifthgearrepair.com/nv4500repair.html

I was all ready to double locknut mine and call it good, glad I didn't now, because I had the updated shaft in mine already, so I doubt just the double nut would have worked.

 

Thanks for the info Patdly!

Called Vern at fifthgearrepair and have their $145 part being shipped.

Asked them about how their device was better than the latest Dodge locking bolt kit ($80 local dealership). They said they still see failures from that kit.

He said if my original bolt looks fine I can put it back and slip their device over it for a permanent fix (until the shaft wears out).

We'll see what happens.

 

I wish I would have taken pictures before I buttoned mine up, but things are going to have to go awfully wrong for it to come loose ever again. Essentially, the locknut is trapped by the splines, and the transfer case prevents the retainer from sliding off.

Make sure you get a new locknut as well if your kit didn't come with one. Mine didn't, but I already had 2 of the nuts waiting.

 

The chances of ANY 5th gear fix working indefinitely is slim to none. In saying that, there is some that have but the chances of them failing a second time is great. The ONLY real and true fix for the 5th gear problem is to replace the 5th gear shaft with a "fully" splinned shaft. The fact that the OEM shaft isnt fully splinned is the whole reason the gear falls off.....not because of the nut. The reason the nut falls off is because the leverage against it is to great since there isn't enough splines under the gear to keep the gear from rocking. Lugging in 5th gear and poor driving habits in 5th gear is the main reason the gear wants to rock on the shaft. And holding the gear on the shaft with whatever or however you can is simply only "holding" the gear on by force, whereby a new fully splinned shaft would be retaining the gear as it should. And the problem with all the fixes out there is that once the gear falls off the shaft then it compromises the gear and shaft splines which further aggravates the problem even more and places more stress on the remaining splines.

 

I disagree, the fix the OP purchase would be hard pressed to fail. Interlocks the nut with the transfer case splines, these means either the splines or the ears would have to break off. I doubt either would happen with out alot of abuse.

 

The "repair solution" fix from FithgGearRepair.com doesn't interlock the nut with the transfer case splines. I'm not sure what you meant by saying that because the tranny and transfer case have no relation to each other regarding this issue, not to mention that doing what you said would not only be physically impossible.....but it would be excluding the obvious that if the TC was involved then this fix wouldn't be available for 2wd trucks.

I'm not saying this company is wrong either or that their claim is just that.....a "claim". But it obviously depends on who you talk to and what transmission shops that have tackled this issue. Not sure why but if you look up their actual business website, there's nothing about their other repair website and they seem to specialize in automatics, not manuals. Thats not saying they dont know or work on them but ya would think there would be more about manuals if they have a website specific to fixing this particular manual tranny.

Throughout all the years I've read about new updated nuts, locking collars, welding the nut, or whatever backyard fix someone thinks up, the only REAL fix is to replace the shaft with a fully splinned shaft. I dont care what new and exciting concept someone comes up with to hold the nut in place. The nut is NOT the problem. If you read in my last post why I say this.....it only makes sense. You cant solve the problem by patching the issue. If NV would have fully splinned the 5th gear shaft from the beginning then we wouldn't be having this conversation.

 

Have you ever had the transfer case off a NV4500, the shaft is splined, this interlocks with the nut and makes it so the nut can not move. It seems pretty cut and dry on how it works, it immbolize the nut from moving

 

Yes I agree with you and I'm not trying to argue with you either but just stating actual reasons why.....

If you want to get right down to it, if ANY of the fixes "should" work then it would be welding the nut to the shaft. How could it get any better than that????? But nonetheless it still can fail. Why?.....Because as I've said and you will also confirm if you do more research, the nut isn't the problem. Here's a couple links that can confirm what I'm saying:

http://quad4x4.com/NV4500%205th%20Ge...0Solutions.htm
http://www.standardtransmission.com/dodge.html
http://www.drivetrain.com/parts_cata...rhaul_kit.html

The last one even shows their nut and tool to be EXACTLY like the repair solution website BUT.....they go on to say that the fix isnt the nut but the new shaft. So.....in saying this, anyone can do whatever they want and I understand that saving a buck is top priority these days but there is a difference between fixing and repairing.

 

Katoom, then why did mine fail within 500 miles of getting the fully splined mainshaft?

I do not disagree having a fully splined mainshaft is a good thing, but obviously it is not invincible. Time will tell with the retainer idea, but after being in the Glass Industry for 35 years, I have seen bulletproof, and the retainer is as bulletproof as I see any way to be.

Welding the nut to the shaft creates a heat affected zone, and there is no practical way to get around that.

And yes, the retainer only works on 4X4 units.

 

Correct, it slides onto the mainshaft splines and keys into the recesses on the retaining nut, stopping it from backing off......then when the tranfer case is installed, the t-case input keeps it from moving rearward. Time will tell if this is a good repair......I'll let you know!
Katoom, you are correct.....a new mainshaft is the best way to go, however, it will add considerable cost. $500+ for the shaft, plus disassembling/reassembling the trans (which many folks have to farm out to a shop, adding labor costs). Compared to $150 for this fix.....I figure if it doesn't work I'm out the $150 + my labor only.......and I'll call it a lesson learned.

 

Sounds like an improper install to me. Who did the install and did you take it back? Better yet.....are you even sure whomever did the job actually installed the fully splinned shaft or just a new OEM shaft? And just because the shaft is fully splinned doesn't mean that someone can get away with not properly installing the nut as well, otherwise the gear will still wiggle off the shaft. The real drawback of this design is that the 5th gear shaft has no support on one side since its an afterthought design.

And yes, welding is a poor solution but a good weld from a professional welder would be best.....instead of the backyard 110 wire feed, which is probably more common than not.

I guess I'm just not understanding you guys since the TC input doesn't come off the tranny 5th gear shaft. The TC input mates up to the tranny main output shaft so I cant figure how the TC can help hold the new repair solution nut in place. Even if the TC was somehow involved in retaining the nut, what's it riding on? It cant just ride against the case.

And I understand that cost is definitely a factor. No matter, do make sure you give some feedback on how it works.

 

Professional welder or not your not going to have good luck welding on a hardened shaft as it has been tempered and welding it will change this and most likely crack. The gear is hardened as well so yeah, it can be welded and you could bring it by my place, I'm a professional and I'll weld it for you and give you a 5/50 warranty. 5 minutes or 50 feet.

Katoom, the idea behind the fifth gear locking device is old school. I've seen this on old Cats, bolts with the metal locking tabs, before they had lock nuts. Fold one ear down and one ear up against the bolt head and it's not going to back off. The fifth gear fix is the same concept. It slips over mainshaft splines and interlocks with the splines, then the outer portion of the lock interlocks with the nut. When you put the cover back on the back of the tranny the transfer case or yoke it keeps the fifth gear lock from moving backwards. So, as somebody else said, you'll have to strip the slines off the lock, off the mainshaft or something to get this lock off the nut in order for it to turn. By that time you'll have wadded the trans anyhow so loosing fifth gear won't be a big issue.

 

Got it. Thanks for the discussion guys. Interested to see if it truly holds up.

 

Just thought I'd add some updated info on this fix..........
I have approx 2000 miles on this repair so far, with @ 400 of that towing. I realize that's not really very much.....but no issues so far.