nv4500 rebuild

[skyhigh4by]

Got a 2000 nv4500 from a buddy for a case of beer because he blew it up. He never opened it up to figure out what it was but told me that it had been making noises for quite a while and then suddenly one day on the highway it went BANG and then there was nothing in any gears.

I opened it up to find that the main gear on the input shaft is gone...wiped right off the shaft and nothing but shavings to be found. The bearing is completely cooked and wiped smooth. Anyways besides that everything else looks good and seems to function smoothly. The gear on the countershaft has a bit of visible wear but still looks pretty good.

Could I have gotten lucky and maybe its as simple as a new input shaft and maybe just a kit to freshen it up (bearings/synchros)

 

[sweetk30]

no expert on 4500 but have read this is common and also wrong fluid oil . and factory they were little low and every one says 1/2 to 1qrt over fill threw top is best .

 

[1-ton]

The problem is going to be the counter gear to that main gear on the input shaft, which was wiped out. When the inputs main gear went "bang", it had to do something to its counter gear, and when one counter gear is damaged, then the whole counter gear shaft has to be replaced.

 

[tRustyK5]

I rebuilt a NV4500 that had a wiped out input. I ended up replacing the input, the entire countershaft, every bearing, every seal, every synchro. Really the only part I could re-use was the mainshaft.

The heat generated by an input failure melts a bunch of stuff, then the debris created wipes out a bunch of other stuff. Not a cheap rebuild...

 

[82355]

I tried to replace just the visibly worn parts in an NV5600, and it came back to bite me in the ass.

Martin

 

[rompinstompinmudmonkey]

Same story here. I siezed the input bearing and broke the input shat clean off and blew just a few teeth off the gear. I replaced the input shaft and bearing because the countershaft looked good. A few hundred miles later I was pulling the trans again because the teeth on the countershaft broke, taking the new input shaft along with it.

The shock load from when the input bearing siezed had put tiny stress fractures in the countershaft that I couldn't see

 

[bigred81]

On some of the nv4500 transmissions I have been able to replace the main gear on the counter shaft all I needed was a press to press it off and the new one on. The main drive gear on the countershaft is available think it started in about 92 and some 96 nv4500. Agree with the others replace the countershaft it is good insurance and money well spent just so you do not have to do the job again.

 

[tRustyK5]

'95 and newer the counter shaft is one piece. It's only the early versions that were two piece.

 

[skyhigh4by]

Not the news I was wanting to see but oh well thanks anyways. Guess I'll just start collecting new parts for it.

 

[tRustyK5]

Seeing as you're on the island, give Kyle at Northwest Fab a call. He got me all the NV4500 rebuild parts I needed at a very good price. I think he is in Qualicum still.