Dodge Cummins Diesel Forum banner

NV4500 5th gear AGAIN!

10638 Views 28 Replies 13 Participants Last post by  stevezcummin
My 5th gear went out again today (starting making rattling noise). I just got done doing the head gasket a little more than a week ago. This will be the 4th tranny in 172,000 mi. first one dodge replaced at 30,000 mi. then at 104,000 mi we spent extra to get the 5th gear fix. now at 172,000 it happened again. Anyone heard of the torque king fix? Any suggestions? I may just get a black marker and mark out the 5th gear on the shifter and sell it quick. lol
1 - 20 of 29 Posts

· Registered
Joined
·
1,130 Posts
Discussion Starter · #3 ·
Yes it had an after market tail shaft and gear put in with the nut fix. From what I understand it has to do with the splines on the shaft wearing from the splines on the 5th gear, not the nut coming off. The nut coming off is caused by the gear splines getting loose making gear wobble and that makes the nut loose and then it would back off. They fixed the nut coming off but that i feel is a symptom not the cause. I wish I could convert to an auto. lol
 

· Registered
Joined
·
1,130 Posts
Discussion Starter · #5 ·
go to quad 4x4's website. Good info on the 5th gear problem. From what I understood the nut coming loose isn't the problem. it's the splines on the mainshaft that cause the nut to come loose. if thats the case welding it wouldn't help.
 

· DieselAutoPower.com
Joined
·
7,491 Posts
go to quad 4x4's website. Good info on the 5th gear problem. From what I understood the nut coming loose isn't the problem. it's the splines on the mainshaft that cause the nut to come loose. if thats the case welding it wouldn't help.
I've already read up about it there. Tack welding the nut would keep it from backing off. The spline allows too much slack allowing the nut to back off. Tack welding it would lock the nut in place. Course if there's any issues later on, you'll need new shafts.
 

· Registered
Joined
·
22 Posts
i put a half inch tack from a tig welder so it didnt get hot and i got over 600hp and its been great so far knock on wood
 

· Registered
Joined
·
231 Posts
I have done this to mine twice... about every 100,000 miles. It is the angle the splines are cut at. The manufactutere...(GM of course..haha) screwed them up on some of the tranny's. If I were you, I would take that sucker back 99bigred to the place where they fixed the issue. A new shaft would FOR SURE fix the issue. I'd say someone is playing you.

WHat happens is the lock nut (pathetic design) loosens due to the torqueing on and off of daily driving. Once it comes free enough it will allow the 5th gear to actually free spine on the main shaft shreadding the splines on the main shaft where the gear is supposed to be holding on too. Thus the neutral feeling. Spot welding will allow it too hold yes, BUT... if you are running around 650...plus hp then you better not stomp it in fifth under load... it will snap it right off. AND the harmonic driving action will probably crack the weld over time anyhow...
 

· Registered
Joined
·
206 Posts
had the same problems and the spline on my gear had gotten so bad that welding just the nut wouldnt have helped so me being tight with my money i welded the gear to the shaft. well that fixed it for about 6 months then it eat the weld right out but it wound up spinning the gear where there was no more splines left. so i had ot do the new mainshaft and gear. i got the shaft gear new nut and bearings with shipping for $360 so i just went ahead and swaped everything.
 

· Registered
Joined
·
231 Posts
DAM...where did you find that deal?!?!?!!
 

· Registered
Joined
·
206 Posts
DAM...where did you find that deal?!?!?!!
ANAHEIM GEAR or there number is (800) 477-1103 . didnt seem like a bad price to me at all, nad they seemed to be some really good people just from talking to them.
 
  • Like
Reactions: Broke Down

· Registered
Joined
·
1,130 Posts
Discussion Starter · #12 ·
what kinda a shaft was it? Anything like the "Torque-King design? Where the splines only provide torgue to the shaft and not trying to hold the gear straight too?
 

· Registered
Joined
·
206 Posts
no it ended up beening one with full splines and a lock ring then a washer adn a nut with set screws and there are places in the shaft to make the back end of the nut fit into with a few hits of a hammer and a chisel. my factory one had over 200,000 miles on it before it went out so i figured i would see how long this one last. and plus i could by a few of these for the price of one torque king. and i know alot of people use the torque king and say it works great but i was looking at it and i see they have a different design but they also have 3 nuts that go on behind it and i have done alot of mechanical work between cars adn trucks to copper and gold mines and saw mills, and if we dont want something comeing off we just double nut it. i dont know i was gonna go with torque king but the price and seeing that they had triple nuts to do it made me wonder how great the fix on the splines really was. now i know i will have someone not likeing what i just said but, its just my opinion.
 

· Registered
Joined
·
360 Posts
i got the torque king kit off quad4x4s site. never had a problem with 5th gear since, although the tranny builder that did mine was a complete moron :banghead: and didnt put it together right for the second time!...its now at another shop that ive herd does great work.

but ive put about 60k miles on the torque king mainshaft before i broke 3rd gear...havent had a problem with 5th yet.
 

· DieselAutoPower.com
Joined
·
7,491 Posts
had the same problems and the spline on my gear had gotten so bad that welding just the nut wouldnt have helped so me being tight with my money i welded the gear to the shaft. well that fixed it for about 6 months then it eat the weld right out but it wound up spinning the gear where there was no more splines left. so i had ot do the new mainshaft and gear. i got the shaft gear new nut and bearings with shipping for $360 so i just went ahead and swaped everything.
Did you buzz it with a stick welder or wire welder and called it done?
 

· Registered
Joined
·
231 Posts
when you put it back together take a punch and mess up one area's threads behind the lock nut, then if you need to work on it again you just drill out that area and unscrew the nut
This wont work, atleast I did another truck, and they had done this... it just rocked itself right through the worn area eventually, dont know how long it took, but it came off again!
 

· Registered
Joined
·
1,130 Posts
Discussion Starter · #20 · (Edited)
if you weld the nut to the gear what keeps the gear from working against the shaft and fretting? That seems to be the problem. If the gear wears against the shaft it starts to wobble and then break the weld? That torque king shaft has a shoulder on the front and rear that holds the gear straight. Then the splines only have to keep it from spinning on the shaft. The other designs rely on the splines to hold the gear straight on the shaft. It may not come off but it doesn't solve the wobble as far as I can see.
 
1 - 20 of 29 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top