NV4500 gear whine

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Ifyasquintitsmint

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Tons of whine from my NV4500, wondering if people think it’s the normal “loud” NV4500 or if it needs a repair.

If it needs to be rebuilt any recommendations on kits? I’ve got the repair manual /a few YT videos doing tear downs.

I’ve no idea how to share videos here so here’s a YT link w the noise:
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squaredeal91

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Check your transmission fluid level and all u-joints
 

Ifyasquintitsmint

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Fluid was filled just prior to the video, I'm running Redline as I saw some people had success with it.

U joints seem good, but I've never checked Ujoints for play before
 

squaredeal91

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That does sound pretty rough the more i listen. When at a resting idling in N how much sound does the transmission make when letting out the clutch. Do you hear bearing noise then or is it pretty quiet like it should?
 

Ifyasquintitsmint

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That does sound pretty rough the more i listen. When at a resting idling in N how much sound does the transmission make when letting out the clutch. Do you hear bearing noise then or is it pretty quiet like it should?

Its pretty quiet in neutral with the clutch out, the noise is only in gear and moving
 

SquareRoot

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I just rebuilt a 4500 with premium parts from Torque king. Inspected and mic'd everything and put it together with perfection. Got it installed along with a new 205 T-case and took it for a spin. I was immediately disappointed. The noise was no better than the worn out 4500 that I replaced. I was at a loss because I knew for a fact it was put together right and everything was new. Internet research revealed no less than 50 threads about the exact same issue. The consensus is these transmissions are VERY noisy by design. The way the gears are cut, the extreme weight of the massive parts, a steel case and a huge countershaft full of gears that freewheel all contribute to the noise. Most folks, including myself, just accept it and move on. After I put in sound deadening material, insulation and new carpet it's livable. It does make me wonder if the first trans was actually bad now that I know even new ones are noisy as hell.
 
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Ifyasquintitsmint

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I just rebuilt a 4500 with premium parts from Torque king. Inspected and mic'd everything and put it together with perfection. Got it installed along with a new 205 T-case and took it for a spin. I was immediately disappointed. The noise was no better than the worn out 4500 that I replaced. I was at a loss because I knew for a fact it was put together right and everything was new. Internet research revealed no less than 50 threads about the exact same issue. The consensus is these transmissions are VERY noisy by design. The way the gears are cut, the extreme weight of the massive parts, a steel case and a huge countershaft full of gears that freewheel all contribute to the noise. Most folks, including myself, just accept it and move on. After I put in sound deadening material, insulation and new carpet it's livable. It does make me wonder if the first trans was actually bad now that I know even new ones are noisy as hell.
Yeah, I've heard these transmissions are pretty loud. I posted in a NV4500 page on FB and got conflicting responses there on if the sound warrantied a rebuild vs just a loud transmission. Does the video seem to portray my transmission as being roughly as loud as yours? I also have new sound deadening and new carpet over it, but theres a 6" square hole in the floor that I'm sure doesnt help.

I've driven a bunch of different manual transmissions and none sound like this so I just want to verify its good before I drive it 50 miles to get tuned.
 

SquareRoot

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The whine isn't of concern, that's gear noise. Bearings failing have a scratchy, rough, grinding sound. I have over 1000 miles on mine and I just drained a fluid sample and it looks as good as new. The old trans had the GM unobtanium, $30/quart fluid in it and the new one is Redline. I noticed no difference in noise or performance (except $$$). How does yours shift? If it ever had conventional gear oil in it the carbon syncros are bad and will eventually make it impossible to shift.

Do you ever recall how loud the UPS/FedEx trucks used to be? Most of those had 4500's in them. Now it makes sense...lol.
 

Ifyasquintitsmint

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It doesn't shift great, can take a bit to find the gear. Doesn't struggle to get into gear however.
 

SquareRoot

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They make brass synchros. It probably won't shift butterfly smooth like the 4500 is known for but one could use regular gear oil in it. I'd bet that would reduce the gear noise drastically. It's just a labor intensive experiment to find out.
 

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