Have you guys ever really read thru your maintenance schedule &quot;booklet&quot; that came with your truck. I was going thru mine today and it says at what mileage to change this and that and check this and that. But thru the entire book totalling 200,000 miles, it never once says to replace manual transmission oil. Diffs and transfer case oils get changed about 30 times but not the tranny!!!! Strange!<br>Is this book a Canadian thing only or do they come in the U.S. sold trucks?<br><br>Just curious

 

It also does not say to change the differential fluid unless you are in the severe service catagory.

 

I change mine every two years. That is probably overkill but it works for me. None of those fluids are filtered, cooled, or cleaned in any way and moisture will collect causing sludge in the gear boxes. Some will probably say I'm full of it and they are probably right but I change my fluids and don't have any problems.