oldblu

posting for my dads truck. He was pulling 24' gooseneck trailer and whoom. no 5th, so he's heard of the common 5th gear nut problem so dropped to 4th called me and i told him keep driving home. Well all was great untill another 30 miles down the road and stopped at toll booth, put in gear to proceed and then nothing. Truck wouldn't move in any gear including reverse. Truck is 01 3500 4x has superchip () and sb dd 3250. Have had rear end redone recently also so thats rulled out. Truck has 140k not tons of miles but a farm truck so not easy miles.
He said never made any horrid noises, clangs, bangs or nothing at either event. My thoughts is input shaft but im not real familiar with the nv4500s
hope someone will have thoughts or ideas.
thanks

Tate

Has he made sure the t-case wasn't slipped into neutral? I wouldn't think the input shaft would break silently

oldblu

yea because tried it in 4x hi and low and back to 2wd.
any more ideas? im stumped
gonna unload it off trailer and start by taking back tailshaft section off to look at 5th gear delima

patdaly

Welded nut gear? I would think it had to be something on that order.

oldblu

Nope, bought truck new and this is it's first attempt at the 5th gear nut failure.

oldblu

Update, figured out truck will move in fourth. But 4th only
So no I'm really stumped...

patdaly

Wow, that's a new one. Looking at the NV4500 diagram, almost looks like 2 problems, first 5th gear nut pops off and then at some other point, the mainshaft breaks in front of 4th gear, that sure looks like the only way you would have only 4th. It feels like it is shifting thru the gears?

Purplezr2

I would plan on pulling the whole tranny, sounds like you have bigger issues.

oldblu

Yea I don't know much about them, but sure doesn't make sense to me.
I read a post somewhere about similar symptoms and the cause was the shifter poped out of the rails. So I took shifter top off and it was just fine and it felt fine before just wanted to double check
Moved each rail with bar without top and they all seem normal
Guess gonna call tranny shop in morn
Thanx for all the help guys.

98fargo

If memory serves fourth is the only gear that doesn't use the countershaft, so possibly a problem with it? Someone correct me if I'm wrong. That would explain only the fourth gear as it is direct on the mainshaft, all others use the countershaft.

Tate

You beat me to it. Sounds like the gear on the input shaft or the front gear on the countershaft has failed. If you lost teeth, you should be hearing a lot of noise in there, so possibly the countershaft sheared. 4th engages the mainshaft directly, so that will work as long as the input and mainshaft are intact.

Post some pictures when you get it dug out.

rich

had this happen on my nv4500 about 5 times. You sheared the teeth on the gears in the main box on the upper and lower shafts. Once you get it repaired run an extra qt of oil and put transcoolers on it to help prevent this from happening.

oldblu

ok dads gonna call local reputable tranny shop and see when can get it in. appreciate all help. and will post pics when get it all appart.

rich-dont guess by chance you remember roughly what cost you to repair?

Pinkston

I spent $1500 on my 4500 recently replacing a broken countershaft, bearings, and having it rebuilt.

dieselfreak21

That is what mine cost at well. You have a couple choices on the main shaft replacement. Standard Transimission's fully splined shaft or QUAD4X4 Torque King shaft (more money but best solution) Sounds like the conter shaft broke as well. Depending on the load and the engine torque when the 5th went caused problems on the counter shaft. That could raise you rebuild cost a little as all of my gears and counter shafts were in great shape. My guess is with the break this truck regulary see's over 21k lbs.