Engine/Transmission (1998.5 - 2002) Need advise on differential fluid change interval

[Pit Bull]

My truck is a daily driver. Very, Very limited towing or hauling and driven normally 20 hiway miles at a time. No rush hour driving. I would call my use "Schedule A" as defined in the service manual. I changed my rear differential fluid to Mobil 1 75w90 at 50K miles but have not changed my front differential fluid. My reason is that 4x4 is only used 4-5 times a year for no more then 20 miles total. The service manual states that I don't need to change the fluid front or rear based on my use of the vehicle "Schedule A" but the fluid in the rear was black so I changed it. The fluid in the front is clean looking. So here is my question, would you change the front fluid and if so at what mileage?

Thanks

 

[Bigramguy]

If the fluid looks and smells OK,it probably is. If the front diff doesn't see a lot of use,then the fluid dooesn't either. Only thing I would watch for is condensation or water. We have quite a few low mileage trucks,and all have developed a little water in the front diff.



I went 200,000 Km,which would be 125,000 miles,before changing mine and it was pretty clean,just a little water in it. Oil analysis came back fine,but I had to drain it to fixed my bashed\leaking cover,so I put synthetic back in.

 

[Pit Bull]

Thanks for the advise Bigramguy, I think I will save my money and just keep an eye on the fluid.

 

[Steve Campbell]

IMO...

The front diff can run at least twice as long as the rear between oil changes.