NV4500 Mystery Noise
 

Hello!
Wondering if anyone has heard of this before. I have used a chevy NV with a dodge input shaft (read my sig)
First,
The noise sounds like a bad bearing and is very prominent in fifth at 60+mph with a noticable vibration. It is definately caused by backlash/thrust like when you are just at the point of accel/decel. It shifts fine but also has a slight rattle that comes and goes when warmed up and in neutral idling. The clutch is a new South Bend and a new throwout/pilot. Also the Gear Vendor is currently off the truck and out of the equation.

Second,
I had bought a used NV for the build hoping for the best but it made the noise right out of the gate. I didnt have time to tear into it so I bought a rebuild from a local rebuilder. I told him what it was for and needed a chevy NV with a dodge input, he said no problem. I now have the same noise in the rebuilt NV. He said it must be coming from somewhere else. Everything else checks out whithin the drivetrain. The noise is definately in the tranny. Just wondering if it might have something to do with the input shaft change that the rebuilder might not know about.

Third,
I found some time to take apart the old NV I originally had. I found that the rear mainshaft bearing was a loose fit on the shaft and the race was spinning in the case. Also found the rear countershaft bearing was doing the same. Used some bearing retainer on both, reset the endplay to .002 and back in it went. Didnt fix it, I have the same noise. The only thing left could be the countershaft front bearing race spinning as well or something with the input shaft, but everthing looked fine when apart with nothing noticibly wrong that could be making that much noise.

So what do you think?:humm:

Wow, I have had these transmissions apart a couple of times myself. It is really hard to say with out tearing into them. So you have had 3 transmissions and all are doing the same thing?? Have you checked the clearance at the driveshaft output yoke. what about having the drive shaft checked for balance? Ive seen driveshafts get warped.

Stumper... I know. Its been three times in and out with two diferent trannys. drive shafts are new and professionally balanced. End play checks out. I"ve also had the t case apart looks fine and had bought another used one, tried it with the same results. Im baffled, and its not ust a subtle noise, it sounds like the whole thing is going to crap out when i hit 75mph.

This sounds like what just happened in my jeep in December. ended up being a cracked and eventually shearing input shaft. no idea what caused it either. Might want to actually tear into one of the transmissions before it does go boom.

Yeap I agree ^ Last one I had apart has actually broken a tooth off the input shaft and off the cluster gear. seems odd for two transmissions to do the same thing.. Not sure where you get your trans parts. I've had good success from Anaheim gear. anaheimgear.com
Hope they're still in business, its been a couple years since I've ordered from them.

Ive had the used one apart and the shop had the supposedly rebuilt one apart.... inputs are fine.
I currently have the used one in the truck now with all the bearing races retained with permatex thinking it was the races spinning. everything else inside checks out.

Rebuilding one of the NP205's next.