Front Diff Fluid Change

[AppocAlexx]

I've had a few problems with 4x4 not engaging or disengaging on its own. Also while in Auto setting it set off a light for the 4x4. Luckily haven't had to use it much since that stuff happened. So I decided to change the fluid. I was told that the fluid was changed in the front diff before I bought it and after this fluid change idt that was the case. I'm at 103K miles with an 07 Tahoe. Check out the pics and give me your input and thoughts. I feel that there was a little bit too much metal shavings in this fluid. More than I have ever seen. Granted this is the 3rd time I have changed the front diff fluid on a vehicle, but I have always been told that metal shavings is always bad in any oil. Maybe this is normal for 100k miles for the front diff? Especially if it was not changed about 8 months ago when I bought this. If it was changed when they said it was I think I may have some issues with the internals.

I am also looking at replacing the bearings and seals on the transfer case in the near future. I am hearing a slight whine up front and have not had time to try and diagnose the exact issue but when I did some suspension work and CV shafts up front I found that the transfer case was leaking on the driver side from the output shaft area. Not enough to make any puddles or spots on my parking spots but it has to be a slow leak, I had to clean all the bolts off to get the CV shaft unbolted. Open for discussion.


Look close and you can see the silver color in the fluid on the outside of the puddle and in the second pic you can see it as well. Also check out that magnet on the drain plug!






This pictures is all the metal shaving I pulled off the magnet on the drain plug.

 

[MichaelSE]

It doesn't look very good, and I think the previous owner was bullshitting you if he said he had just changed it before you bought it. The whine is worrisome. Did you replace the fluid with a heavier gear oil?



As for 4x4 not engaging/disengaging, this is more likely related to your t-case than your front diff. I did some research on getting stuck in 4x4 after it happened to me 10,000 miles ago (hasn't happened since). Generally it's either the switch itself, the transfer case control module, or the transfer case shift motor going bad. The switch and TCCM are behind the dash, but it couldn't hurt to get under your truck and spray the contacts of the motor with some quick dry electronic cleaner. Might as well change the t-case fluid as well, since your truck is an 07 it will take Autotrak II.

 

[NGAneer]

That doesn't look like enough fluid to me. Mine took most of an 80W-90 bottle of valvoline. Looks like it was low and might've done some damage.

 

[AppocAlexx]

the picture was at the very first before I popped open the filler nut on top to let some air in and bleed it dry. It is leaking some at on the driver side seal but not enough to cause any damage. I know these front diffs are gears pretty high especially if used in 4H