When in 4-Low second gear and up there is a humming noise around the middle to front of the cab that increases with the speed of the Jeep. It sounds more like humming or the "winding up" of some toy rather than "grinding" so that is why I have the question: Should I replace my transfer case fluid / seals or my front differential? Or could it be something else?

Thanks for the help :D

You shouldnt be going very fast in 4lo, but what you're hearing are the planetaries in the transfer case. Nothing to worry about, but do check your fluid to make sure its still red and full.

Thanks for the quick reply. Now, I know how to change the fluid, but if I remove the drain bolt and see that the fluid is red, have I lost enough to warrent removing the fill plug and filling it back up?

Dextron III isn't that expensive in Cali is it?

No not really I just don't have any at home so I'd have to wait until tomorrow to test it out. No biggie :)

Thanks for the quick reply. Now, I know how to change the fluid, but if I remove the drain bolt and see that the fluid is red, have I lost enough to warrent removing the fill plug and filling it back up?


Remove the top fill plug. The fluid should be level with the fill hole, so you should be able to get a good indication of the condition of your fluid from the fill hole and you won't lose much, if any fluid this way. If it looks bad, just go ahead and replace it :D

2 things.
You should be able to remove the fill plug and stick your finger in the hole to touch the fluid if it doesn't already start dripping out when you remove the plug. Level will be fine if fluid is present.
Also,
I am running a Dana 20 transfer case and I use 90 weight gear oil so make sure what fluid you are using befoer you add.

Its DextronIII ATF or whatever. Just pull the top fill plug, stick your finger in, and look at whats on your finger. Also make sure you dont have to dig for it, if its not at, or near the level of the fill plug you need to add it till it comes out.

Sweet, thanks :)