My transfer case is due for an empty and refill, so my process will be

• Go for a short drive to warm things up
• Drain the old fluid - check the magnet- run the initial drain into a coffee filter to check for metal
• Refill with 85/140 plus some blue devil stop leak (1/2 bottle)- I have a leak at the input shaft
• Check the breather ideally remove the hose and run some air through it to check function

So now to the questions

Is the breather easily accessible or even visible from underneath
Synthetic or dino for the transfer case

Anything else to check while I am at it

 

Make sure you loosen the filler before you do anything. You don't want to drain all the fluid and then not be able to fill it again.

 

I think removing the breather is going to be a major PITA. Maybe easier if you remove the shift bezel and go at it from the top, but I've not tried it. Last time I topped off my case, I slipped a bit of hose over the top end of the breather line and pushed some air through while the fill plug was removed. It should be obvious if there is a blockage.

Post back you results with the blue devil, I may try that as well if it helps.

 

@mollusc good reminder, but I topped it up so that part is easy.

@Red5 found a picture on line so I will just try air, no easy way to get that breather

 

Believe me, “go at it from the top” would be the absolute hardest way to do this job .

 

Just one more question,the fluid in there is pretty ugly any point to running some cheap stuff through to clean up any gunk or just switch it up

 

Well both plugs came out easy as did removal of the cross bar, that was pretty evil stuff in there, obvious got water intrusion at some point. Lot of slug on the drain plug a couple small fingernail wide metal bits about 1-2 mm long likely from when the TC jumped out of gear last summer operator error on that one.
And man that stuff drains slow.

 

You removed the cross bar? How'd that go? I need to do the same but sort of nervous given its rust situation.

 

@Brandon318 well mine was removed last summer by a shop so really really easy for me, the problem is they used non captive nuts on top so going back on might be a bit of fun. A metric ton of penetrating oil over a few days might help.

 

All done I was little concerned I only got around 2 liters in there, but the RAVE says that is it on a refill. I will take her for a little drive then let things settle and double check in the AM.