Modular man

My front diff has a slow leak so I'm going to take the cover off it and do a full fluid change while I'm at it . Anyone no wat weight gear oil it calls for and wAt brand should I go with? I was think it calls for 75/140 w but not sure . Thanks

twiggy2cents

75 140 no need for friction modifier

PerryB

My stepfather has a 56 CJ-5 that has drain plugs (3/4" pipe thread) in the bottoms of both differentials. Why can't manufacturers still do things like this?

Modular man

Idk man Alls I no is I take my truck muddin a lot and my diffs are under water a good bit . I like to do a full fluid change front and back atleast once every 6 month to a year to make sure there's no water Inside

jake_85

I did this to mine when I did the gears. Very simple

Modular man

Wats that added a drain plug to the bottom? I should also do that

PerryB

Actually that would be pretty easy. Cast iron drills and taps well.

jake_85

Yes simple

Mod (Ret.)

Costs money to add these plugs during their manufacturing stage. Google a stock diff cover, then google one with drain/fill plugs. Notice the price difference. Then calculate this cost over the wide range of trucks that have been sold over the years. Also take into account how many owners even bother to change their own differential fluid change, and you understand.

They also put longer interval oils in them, as to not require as frequent of an oil change as your stepfathers 56 CJ-5.

They have progressed just a bit since then.

PerryB

Yeah, I know the cost per unit equasion. The question was largely rhetorical. This trend actually started a long time ago. He (stepdad) has 2 CJ-5's. The second one is a 65 and it does not have the drain plugs. It just torques me that the mfgr's keep doing things like this which makes serviceability increasingly difficult. Like some of the newer automatic transmissions that have no dipstick. No explanation in the world is going to justify THAT!