I'm looking to make a fitting to allow for quick filling of my transfer case from the drain plug hole. Am I correct in that the TC drain plug / hole for the Evo 8 w/ACD is an M18 x 1.5?

I think I will need to go from M18 x 1.5 reduced to 1/8-27 NPT, then from 1/8 NPT to 1/4 barb

 

maybe an M18 banjo AN6 with a cap would be better
or you can use a banjo with a barb and use a clear hose to show fluid level

 

just curious, why out of the drain instead of the fill?

t-case refilling is one of my least favorite jobs on this car.

 

The reason is you may not get a true full fill when the fluid pours out the fill hole. If you use the fill hole, you should fill to overflow, drive the car a bit or get the wheels moving while car is on jackstands, and then fill again.

https://www.jackstransmissions.com/b...t-case-filling

 

i add a stub of a 10mm silicon hose (14mm OD) on my fill barb and its snug that I can put all 1 quart in there with no spill, until i need to put the fill plug in. That would still spill slower that thru the drain plug

 

damn, there is no way i can fill the t-case through the drain plug lmao, quickly remove and close sounds like a nightmare. in the past i tilt my car all the way to one side and top off.

 

I just use a fitting that close and use plumbers tape to make sure it seals ok, works ok too.

 

Exactly what I did, M18 x 1.5 to 1/8 adapter and a 1/8 barbed fitting. Screw it straight into drain holes on the transfer and diff (after draining out the old oil) and fill them from below using a 1L hand pump. I can put in exactly the amount I want (overfilling the transfer case is recommended by local people in the know) and I know it's definitely in the diff and transfer. After I've filled them I remove the hose and pop a little cap on the barb, then unscrew the whole thing out of the transfer (or diff) and quickly screw in the sump plug, would say I drop about 15mls of oil doing this, that I account for when I put the oil in. I can do an oil change on the diff and transfer case in about 5 minutes, it's about a million times easier than doing it the "normal" way.

 

hm. it's not super messy when u swap plugs? what pump is that?

 

Fluid transfer pumps work very well

 

No, not at all. I run Diaqueen oils, and both the transfer and diff oils (75w85 and 90w) are very viscous, especially in winter (and that's an Australian winter, so maybe 15c), so very little, around 20mls, comes out between plug swaps, not even enough to have it drip off your hand into the tray underneath. Also, you still have the filler plug installed, so there's a vacuum trying to keep the oil inside, if you know what I mean. The little pump is from a local (Australian) car accessory shop, it's just a 1L hand pump, I'm sure something similar should be available in the States from some car parts seller.

 

ahh ok. yea i may try the same two fittings the OP uses, plus a fluid extractor that can work as a pump ( )

it's not as if the fill until it pours out method is much cleaner, esp the wya i do it (wait until it dribbles, then pump even more as fast as i can and close up the plug)

 

I just use one of these
If you use a check valve that is the correct or equivalent thread diameter and pitch then there is less fluid loss when swapping out the valve for the drain plug. I usually fill it when hot so that is why I prefer using the check valve.

 

i do have that exact hand pump, it is so funny that they explicitly call out red line oil (a fairly boutique oil) as not compatible. I do use it with red line oil bottles

 

i have a similar one from HF. i use it on all the gear oils including red line quarts and gallons. I just stock up on the clear hoses ... the ones from Lowes/HD dont get hard