Well, I have a Silverado on top of my Camaro, and its been having some issues. I tried to get on the Silverado forums, but theres no where near the user base that thirdgen has, and everyone just knows more and you get more help here. So, here goes...

I have a 2001 Silverado LS Stepside standard cab with the 4.8L V8, 4L65E, and the manual transfer case, 172,XXX.

Everytime the transmission shifts out of first into second, it gives off this screeching, grinding noise like rubbing two coins together. It only does it if I shift at under 2,000RPM, and if I shift above 4500RPM in second to third under heavy throttle, which makes me think that could be the one or more of the many heat shields under the cab.

I got underneath the truck today, and I saw that the rear main seal is leaking from the back of the transfer case, but not too bad.

I am wondering if the transmission and the transfer case share the same fluid between the two units, or if they both use the same fluids, and well what could be making the noises I'm hearing.

I checked the fluid levels in the transmission and they are full, but I do not know how to check the fluid level in the transfer case.

The transmission itself shifts good, nice firm, crisp smooth shifting, but it just makes this noise.

I checked for play in the driveshaft and the u-joints appear to be alright without me taking the driveshaft off the truck, and the transmission mount also looks good, so the whoe drivetrain is at the right angle, and the u-joints can't really be doing much to it to make it do this.

Also, when I am driving on the road with 4WD on, when I slow down to stop it makes this weird clearly audible noise from either the front axle or the transfer case.

So my thoughts are that I need to fill my front axle, and transfer case, replace the rear main seal in the transfer case, and possible replace the u-joint for good measure.

Does/has anyone else had these issues with their trucks in the same way I am? What does everyone else think I should do? I would like to get this fixed so I don't damage anything. Using the 4WD isn't an issue right now, theres no snow or anything but I do want it to work if its there.

I would appreciate any and all help, advice on this, thanks guys!

 

U-joints are a cheap fix and dont take more than an hour or so... I'd knock them out 1st and see what happens from there... you'd be surprised what kind of stupid noises they make lol

 

They can even make a grinding noise? haha

 

Well I replaced the u joints and the noise is still there...