I've been working on getting the NV4500 rebuilt, and converted to 4wd. I just finished assembling the back side of the new fully splined 4wd mainshaft and went to install the rear bearing expecting it to be "tight" and the bearing fell into place!!

I measured my old 2wd mainshaft where the bearing sat and it measure out to 1.877". The new mainshaft bearing surface measures 1.874" and the ID of the new bearing is 1.875".

Anyone else run into this issue before? And any suggestions on what I can do to fix this issue...or should I try and get a replacement mainshaft from the company I bought it from....I bought it months and months ago so I'm sure there will be no warranty, or exchange.

 

OK I think things might be usable as they are. I was looking, and thinking about things and noticed that the 5th gear rides against the inner shell of the bearing.





Once the nut on the 5th gear is torqued to 250 ft/lbs it should lock that inner shell in place.

Thoughts?

 

suprising clearance is that close with it going loose, new Asian shafts will fall either way, but the bearings will take the opposing tapered thrust when shimmed, id still check against another shaft if possible, ive seen that variation corrected with another new part

 

also, if your going with it, after the mainshaft upgrade, don't hesitate to locktite shaft nut

 

Thanks for the advice Sooty!!

I got a response from the company I bought the upgraded mainshaft from...Here's their reply.

So I guess it's good to go.

 

ive seen the same with the 5600, not so many aftermarket options yet, parts are tighter or looser, "you cant use the part we make to mate with the stock shaft" was one reply, some new parts are not available, im a lot happier when the trouble to disassemble is repeated during assembly. the tight components don't need press installations, to avoid surface scoring, ill freeze the smaller shaft, then torch or heatgun the larger gear or synchro to slip fit, it shrinks immediately to its correctly installed position without any trouble, keep things the way their supposed to be! btw when you torque the mainshaft nut, put trans in 2 gears to lock the shafts, I made a tool from a auto trans castellated bushing, that allows for insane torque, the locktite will save the finished job.

 

Thanks for the info Sooty....Glad to here that I'm not the only one to experience this issue.

 

Sorry but when I read this real quick at first I saw manshaft and um, well, the too small part and...

 

.........

 

Only issue I see with this is that you can't properly set your main shaft end play unless this bearing is torqued down with the 5th gear nut.

Since there is a thrust washer beneath the bearing that needs to be compressed tight, and the other components on the mainshaft that might shift and move once under the load from the 5th gear nut.