Vibration after Diff Fluid Change - Pls Help

[86Burban]

Need some help please!

-86 Suburban k1500, 4x4
-Changed front and rear diff fluid - synthetic
-Filled to just seeping from fill plug...let sit till done dripping out then secured plugs
-drove and now have vibration...can't tell if from front/back as it is in both steering wheel and seat

Did I overfill? If so what distance below the fill plug holes should it be?

Thanks, e

[86Burban]

Anyone?

[Dieselburb86]

Sounds like a drive shaft to me! I drive a 1986 GMC suburban and the rear drive shaft has a nice size dent in it towards the dif, and its causing the same type of vibration.

[Smier]

I've always filled mine till it comes out the plug. Is it "whining" at all? Was the truck sitting level when you filled it? Pull the plug and stick your finger in, is it low? I did the same thing once and after driving a few miles I had a vibration and "whine" from the rear differential. I pulled the plug and I was low on fluid. I guess I didn't allow enough time for it to ooze everywhere it needed to. Topped her off and I was good to go. Other than that, check the ujoints for sure.
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[86Burban]

Originally Posted by Smier

I've always filled mine till it comes out the plug. Is it "whining" at all? Was the truck sitting level when you filled it? Pull the plug and stick your finger in, is it low? I did the same thing once and after driving a few miles I had a vibration and "whine" from the rear differential. I pulled the plug and I was low on fluid. I guess I didn't allow enough time for it to ooze everywhere it needed to. Topped her off and I was good to go. Other than that, check the ujoints for sure.
Posted via Mobile Device

Thanks...no whining that I can hear. The vibration has quited slightly but still there. I will re-check the fluid level (but did find in the owners manual where it did specifically state to fill to the drain plug level).