---- Thanks in advance for any help with this! ----

Before I forget, my truck is a 2WD 1998 24V Ram 3500 DRW, has a little over 230K.


I got this truck last week, and on the way home (~130 miles on the highway) the truck was absolutely fine until I got close to home. About 5 miles from home I got caught at a stoplight, and after the light went green, off I went, right through the gears- that is until I rowed to 5th and the truck quit pulling. Well after shopping for a late 2nd gen Dodge for over a month, I had already heard about the nut that holds 5th gear in place on the mainshaft sometimes falling off, so as soon as I got in the door I started searching the web. Found all kind of great info, and this morning finally got around to pulling the tail housing off the trans. I should also add that this transmission appears to have been recently rebuilt, but I have no records with the truck. When I removed the housing, I was VERY surprised to see that 5th gear appeared to be exactly where it should be and the nut (an updated type) was tight.
There was some evidence of rubbing in the housing from the 5th synchro gear so I took a closer look at that and the snap ring shot off like a rocket. I guessed it had been half cocked and that kept 5th gear from locking in when the shift fork tried to engage it. SO I reinstalled the parts and the snap ring and put everything else together, filled the trans with gear oil and hit the road- still no 5th gear. :flamingmad:

So, anyone got an idea what could it be? Until it stopped working, it was totally fine. I didnt lug it in 5th at all and havent pulled anything with it. The gear oil I drained out was in great shape, like I mentioned above the transmission has evidence of being rebuilt in the past few months so I am surprised this would happen... but I really need to get my truck back on the road!

(uploading pics now)

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IDK, but it sounds like a crappy rebuild.

 

does it actually shift into 5th and does it make any noise when in fifth? The reason I ask is the splines may be rounded off on the shaft and the fifth gear and not show any signs outside untill you pull the gear off. The nut looks like an old style nut also.

 

OK well after messing with it today I am left wondering if I have to rebuild it, who sells affordable rebuild kits? After all, I did just pay for the truck, now having to do a major repair is gonna hurt a little. Does anyone still offer a NV4500 mainshaft that will solve the common 5th gear problem? If I have to go that route, I only want to go there once, know what I mean. Also- are the aftermarket short shift kits I have seen for sale worth messing with? I would love to tighten up the shift throw a little bit.

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Yes the shifter moves into 5th but when I let the clutch out, nothing. No noise that I can hear.

The nut has 2 or 3 small set screws, I realize this is not the split style nut sold by the dealerships but my understanding is that the factory nut would not have set screws in it.

 

This will help check it out
https://www.dieselbombers.com/dodge-...ar-issues.html
I belive southern gear sells shafts here in atlanta.

 

Is noone else thinking that the problem may have something to do with the wear present on the inside of the tail housing?

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I will take a look, thanks for the link!

 

Southern Gear Co. - The Standard Transmission Professionals

 

The picture you attached to post #19 in that thread is a good shot to get a comparison against what mine looked like today. I just dont understand how if my 5th gear nut is tight, and my 5th gear is in place, what could be keeping it from engaging? I understand your suggestion that the splines might be gone both on the gear and the shaft, but there was ZERO visible metal in the gear oil I drained at all and when I spun the shaft by hand 5th gear was engaging its synchro gear properly. If the splines stripped I would expect excess play in the 5 gear and at least metallic filings in the gear oil...

The parts held on by that snap ring on the 5th synchro gear, does anyone know what they are and what exactly they do? Could something be wrong there (or further in the transmission) causing loss of 5th gear and the wear inside of the tail housing?

Forgive my ignorance, 11 years of mechanic work and I managed to avoid tearing into a standard transmission... and now I have no choice!

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Jet- this is beginning to make more sense now, but I really hope it isn't the case.


I know its hard to tell from the pictures, but this appears to be a full splined shaft, grooved for thrust washer, with an Aftermarket Nut (3 Set Screws and Brass Pads).

According to what I have read:

Trouble is... I had no loud noise at time of failure and could see no metal in the gear oil that I drained. And I am not deaf or blind (yet). Also the gear did not freely move independant of the shaft.

Maybe I didn't beat it hard enough, perhaps I should go start the truck up, put it in fifth gear and sit in the driveway idling for 10 minutes, then tear it down again tomorrow and have a look.

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This 911 help section is a great idea BTW, thanks DB.

 

get the updated nut from dodge also check the shift dogs make sure none are broken

 

The outer sychro ring is installed backwards.Caused the rubbing on the tail shaft case.the bevel of the ring should be aft.