So I recently bought a 2001 Silverado with a 6.0 and 4l80E swap. I drove it for about 1,000 miles and than the transmission was making a grindy noise in 1st but went away in 2nd. It still shifted fine and I didn't feel any difference. I took it to a trans shop anyways and they said the trans was on it's way out. So I spent $3,000 and had the whole thing rebuilt at 110,000 miles.

The shop than told me that the noise didn't go away and I decided to drive it a few days and see what it's all about. The shop said they would swap it for a different trans that was rebuilt the same way for free if I didn't like the noise.

When I picked up the truck after I had it rebuilt to hear the noise that was still there it was a different kind of noise. Instead of a grnd ish noise it was a whine. Not a light whine that I hear people talking about these make. But a whine like you are in a big city bus or a newer school bus is what I compare it to almost exactly. It fills the cabin with noise almost like it is super charged or something. Maybe I have super sensitive hearing or is this the whine people commonly talk about these having. (I don't know if they put straight cut gears in or not the shop has a really good rep but for $3,000 this thing should be perfect)

 

I had that happen in an 80e I had at one point. Pretty sure the pump was about to go out.

 

So did getting a new pump make the whine go away?

 

I cant remember exactly since I had a lot done on the rebuild, but I do believe the sound was the pump.

 

My last 4L80 whined in first gear, did that for 5 years before it died. New transmision does not seem to whine tho.

 

The shop offered to swap it for a transmission they have and swap over the Torque Converter and my Shift Kit but I don't know about this mystery transmission and I would hate to have the down time on the truck again.

 

After doing a google search that whine seems to be common and not really a problem. When my last 80 died I dont think the whine had anything to do with, I heard and felt a loud boom grinding and it left me walking close to home. I wouldn`t worry about it unless its so loud that its really annoying.

 

I guess I'm asking how loud is the normal whine because I also saw that it is normal but mine sounds like my truck is super charged in 1st gear. I don't know if that level of noise is what everyone else has hears. Guess I'll rock with it unless someone posts something other wise. If it blow I'll be back on here lol