Drain plugs and drain plug types for gbox/transfer and diff housings are all different

[sunrk]

Did oil changes on manual gearbox, transfer case, and rear diff today due to it being a sunny warm day before wet weather returns

I'd never paid much attention to it before, but the drain and fill plugs on each are not the same.

On the gearbox, both fill and drain plug are the older flat head style and don't have any washer. Drain plug is not magnetic.

On the transfer case, fill and drain are the newer chunky head style plus the drain one is 19mm head not 24 mm.

On the rear diff housing, fill is newer chunky head while drain is older flat head but is magnetic (and has a metal washer).

Dunno about the front diff as I didn't have time (or enough oil) to change it's oil today.

I see that having the flat-head drain for the diff housings makes sense as the head is then 'protected' by the formed ring welded into the housing.

The old oils all looked not very nice but only the rear diff oil looked 'wierd' (can't describe it properly).

I'm presuming all drain plugs (not sure about the motor sump) should probably be a magnetic type? Does it matter for gearbox and transfer if they are older flat head or newer chunky head type?

 

[mudgudgeon]

Does it matter for gearbox and transfer if they are older flat head or newer chunky head type?

Did they keep the oil in? Doesn't matter then.
If they didn't, you may have a LandRover!

Magnetic plugs in diffs and gearboxes are handy as they give an indication of gear wear in a unit that doesn't get regular oil charges like the engine does

 

[NeverFinis]

IMHO, I think decisions for which fill and drain plugs to use were made when the parts were designed...and they didn't go back and update the plugs for older parts (axles vs t-cases/transmissions).

Toyota does sell a low profile hex magnetic drain plug that many people use for all those locations, even for the fill plugs.

I replaced my diff drain with the same as the original because the magnet was larger than the above drain plug and I thought maybe Toyota had a reason for using the larger magnet in the diffs. I kept the fills same as stock, but I could see using the above magnet type. A magnetic fill plug would help give an indication of wear without the need to drain the fluid. In the end, probably not necessary,

 

[calokie]

I ordered the magnetic drain pugs from local dealer, unfortunately Witzend website is shut down so you have to find the part numbers the old fashioned way

 

[Madcrix12]

TC drain
90341-18057
TC drain washer
90430-18008
TC Fill
90341-18006
TC Fill Washer
90430-18008

Rear Fill Float Fill
90341-18006
Rear Full Float Fill Washer
12157-10010
Rear full float diff drain
90341-18040
Rear full float diff washer
12157-10010

Front diff drain
90341-18040
Front diff drain washer
12157-10010
Front diff fill
90341-18006
Front Diff Fill Washer
12157-10010

 

[sunrk]

When I think magnetic drain plug, this is what I'm used to seeing them look like.