[HoosierDaddy]

I too replaced my differential fluid today. I have a friend who does mobile heavy equipment repair so I had him come today to help me change engine oil, grease, check brakes, and change dif fluid. Dan stuck his finger in the fill hole and said " this fluid looks new" I already had 5 gal. of Mobil synthetic 75W90 and had already decided to change any ways since I had no idea how many miles are on it. There is 136,000 on the coach so I'm assuming the fluid was original fill. There was maybe a tablespoons worth of shavings on the magnetic plug. Thanks to Bill for sharing your experience and giving us a "Heads up".

[bikestuff]

Gang,

Well I have the coach back from repair shop and wanted to give you an update.  

The repair included a new differential as well as new wheel bearings all around.  They found a broken brake caliper and several cracked brake rotors.  (I will attach part numbers in a later post)

The best guess as to the cause of the failure is believed to be lack of oil in the differential.  Almost no oil came out when the axle was removed...and when the bell housing was split they said there was at most 1/2 gallon.  There was no oil on bottom of coach.

Since checking the differential fluid is not on the Newell annual maintenance checklist, it was never checked on my coach.  Newell did research on my coach and they determined that my diff fluid was changed when I bought coach from them in 2012.  (Mileage 165k). So.....sometime between 2012 and 2016, the fluid must have leaked out.  

Here is the interesting bit.....The coach drives very differently now!  On flat ground it drives as it has always driven.  But going up and down the hills on I-49 through northern Arkansas the jake brake now makes a huge difference.  I can really feel it slowing me down.  Before, I could tell the jakes was doing something, but would not keep me from accelerating down the big hills.  Could it be that the differential has been close to failing the whole time?  Who knows!!?

TL;DR The new differential makes the jake brake work better.

Ps. My brother says no way. I agree it does not make sense.