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Thunderbolt's avatar
Thunderbolt
Explorer
Feb 01, 2016

Silverado Whining above 40 mph (UPDATE)

I have been chasing a whine in my truck for about 7,000 miles now on my 03 Chevy 2500HD with no luck. When driving the truck above 40 mph it is there is a whine that sounds similar to the pinion bearing. It goes away if I let off the gas or shift to neutral and it sounds like it is coming from the transmission or torque converter. It hadn't been getting worse until yesterday and now it seems a little louder. Two different shops have drove it in the past and said it is not the transmission. Could a bad pinion bearing transfer sound that much ? Any other ideas on what to look for would be appreciate it.

Transfer case is apart and man did I dodge a bullet ! The only damage is the rear output bushing and the cause of the problem is the pump failed. My buddy said I was lucky I stopped driving. Everything else in the transfer case looked good. New pump and bushing on the way. I am also going to put another new driveshaft yoke on.
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31 Replies

  • Thunderbolt's avatar
    Thunderbolt
    Explorer
    Feb 22, 2016
    Well I pulled the rear driveshaft and drove the truck in 4 hi. The noise is still there so it isn't the differential. The fluid that came out of the t case looked dark again. Looks like the t case is coming out again. The transmission fluid looks like the day I put it in and the t case fluid looks dark. I know it will be dark under a normal change, but this t case was just disassembled. It has to be a bearing or something.
  • Thunderbolt's avatar
    Thunderbolt
    Explorer
    Feb 19, 2016
    It isn't good to drive it far, but won't hurt it to try and find the noise. It is hard on the auto-trac transfer case, but I don't have that. The Transfer case has the proper fluid in it.


    {tpc} wrote:
    Just a quick question...how can you pull the rear driveshaft and drive it? I mean I assume you could put in 4x4 mode but I suspect this might be a very bad thing to do.

    Servicing the front and rear diff fluid is almost as easy as the transfer case. With the transfer case did you use the proper fluid? I know some call for the ac delco stuff, some its something else.

    If your going to drain the front diff to check for debris, be sure to remove the fill plug first before the drain, just so you know you can get the fluid back in. I suppose the same can be said for the rear but I think replacement diff covers are easy to get if needed.
  • _tpc_'s avatar
    _tpc_
    Explorer
    Feb 19, 2016
    Just a quick question...how can you pull the rear driveshaft and drive it? I mean I assume you could put in 4x4 mode but I suspect this might be a very bad thing to do.

    Servicing the front and rear diff fluid is almost as easy as the transfer case. With the transfer case did you use the proper fluid? I know some call for the ac delco stuff, some its something else.

    If your going to drain the front diff to check for debris, be sure to remove the fill plug first before the drain, just so you know you can get the fluid back in. I suppose the same can be said for the rear but I think replacement diff covers are easy to get if needed.
  • Thunderbolt's avatar
    Thunderbolt
    Explorer
    Feb 19, 2016
    Transfer case in and guess what ? The noise is still there ! We had it on the hoist and can't tell if it is the transfer case or the rear differential. We can hear it in both places. My mind says it is still in the transfer case, but I am going to pull the rear driveshaft and drive it to see what it does and pull the diff cover to see what it looks like. It needs the fluid change anyway. I am getting frustrated. My biggest problem is money ! If I could afford it I would just leave the truck and say figure it out. My buddy is doing this as a favor and trying to help so I don't expect him to spend a lot of time on it when he has plenty of work already.
  • 72cougarxr7's avatar
    72cougarxr7
    Explorer
    Feb 12, 2016
    When I worked at the local Chevy dealer, the sealant that was used on the transfer case mating surface was called "anaerobic sealant".
    It looked like Loctite and cured from pressure, not exposure to air.
    Permatex and Loctite both make it.
  • GeoBoy's avatar
    GeoBoy
    Explorer
    Feb 09, 2016
    I won't use silicone on those cases, when I worked at a Yamaha dealership in my younger days we used a product called Yamabond #4 and it worked great no leaks and no pieces floating around like silicone sealant.
  • Thunderbolt's avatar
    Thunderbolt
    Explorer
    Feb 09, 2016
    Warning to all those who repair pump rub themselves. DO NOT use too much silicone on the case halves. Silicone debris plugged my pump filter causing it to fail. I was lucky ! The shop found a couple other parts with wear and the bill is 384.00 plus I have to buy another new driveshaft yoke for 120.00 as well as put the t case back in the truck. Very costly learning experience, but it could have been worse.
  • GeoBoy's avatar
    GeoBoy
    Explorer
    Feb 08, 2016
    Perrysburg Dodgeboy wrote:
    GeoBoy wrote:
    You should use a synthetic lube like Amsoil Torque Drive and over fill the transfer case by 1 quart. To overfill remove the switch in the top of the case and add the lube there.


    Why would you ever overfill any component? This will cause seal failure any could cause the component to fail also. Not a good idea at all!!!

    Don

    This was recommended by the people that rebuild these transfer cases. I did overfill per their recommendations and it never leaked a drop in 30+ thousand miles.
  • Perrysburg_Dodg's avatar
    Perrysburg_Dodg
    Explorer
    Feb 08, 2016
    Adding more capacity like a larger/deeper oil pan is OK as it does not raise the oil level inside the component itself. This is usually done to add cooling capacity but the downside to that is longer warm ups in the winter.

    Don
  • RCMAN46's avatar
    RCMAN46
    Explorer
    Feb 08, 2016
    Perrysburg Dodgeboy wrote:
    GeoBoy wrote:
    You should use a synthetic lube like Amsoil Torque Drive and over fill the transfer case by 1 quart. To overfill remove the switch in the top of the case and add the lube there.


    Why would you ever overfill any component? This will cause seal failure any could cause the component to fail also. Not a good idea at all!!!

    Don


    It will also cause more friction and churning up the oil and may lower the lubrication ability of the fluid.

    Overfill your engine by 50% and find out what will happen.

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