Nv4500 issues (surprise surprise)

zenzen_427

zenzen_427

Scuba Steve
Joined
Feb 27, 2010
Messages
155
Have gone through 3 nv4500s in my 98. Broken countershaft, broken 3rd gear, Wore out syncros. All different instances. Soooo I went down to ATS to get the built nv4500 . I swapped inputs as I run a comp dd. Something was off though, unlike stabbing the input where everything went smooth and the input still spinning freely after housing torque it was SUPER hard to turn by hand. Thinking that maybe I wasn't seated into gear in front of the pancake bearing I tapped the input in with a dead blow hammer. Under 3000 miles later countershaft overdrive gear lost all of it's springs and struts making the overdrive sleeve uncontrolable as the shift fork somehow lost its place. I took the input out to put the stock size in to warranty the trans. upon removal all the cylinders fell from the pancake bearing and the thrust bearing was a little messed up too. LUCKILY ATS warantied the trans no questions. I restabbed the input today and although much easier to install (no tapping this time) it is still very hard to turn by hand after housing torque. Any Suggestions? Only thing I can think of is the Race bearing on the input is not pressed on enough at this point and somehow backed off from a previous trans failure. Thanks in advance!
 
you cant just stick a random input in a nv4500. the reason the input was hard to turn is because the trans was built the that original input there are shims in the rear of the transmission that sets end play. the input that you are trying to install has different tolerances and need to be shimmed to that input.. i know alot for guys out there are going to say they put one in with no problem but sometimes you run into this issue.. make sure that the input bearing is all the way down against the input.
 
Guess I'm gonna have to pull the top off yhis trans and check clearance. I read somewhere that you want it in the .005 ballpark. Ill get it figured out tomorrow. Not a random input shaft, billet 1 3/8 valair shaft for the nv4500. Installed hassle free on stock trans...
 
Ran into the same problems as you took it to a good driveline and tranny shop and he helped me get it lined out
 
I ended up ordering a shim kit which should be in tomorow. I have no beef doing it myself! Just got to go get a feeler guage that goes below .006 as that's the smallest feeler I have.
 
Scratch that, I have the dial indicator I need. Thanks for the insight again everyone.
 
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