Was chasing down an oil leak and looking behind the engine from the passenger side I see a little hole in the top of the transfer case. How bad is this and what options do I have for a solution, if it needs to be fixed?


From passenger side.

Closeup.

 

That can't be good. I am sure it could be welded shut. Sucks cause you would have to remove the t case and all but I am sure that will affect your tcase over time with crap getting inside or leaking out considering its by the fill hole it looks like.

 

Thats an issue for sure. The question is not how to repair the hole. The question is, how did this hole occur? Is there something going on internally that caused it? Seems like a tear down is needed. I think i would be inclined to send it to TRE

 

I agree with the rebuild. Jon would be a good guy to send it to for sure. Idk if it was internal or external but its definitely in an odd spot for sure.

 

you sure that is leaking?

i cant remember if mine is like that.. .but it looks like its just the back side of where the bolt goes... maybe when they were machining it it was just a little thin their and came through.
if this is the case... then its fine.

 

I kinda thought that too, but if you look its lower then where the bolt is. I mean maybe it is what you said and just a weak spot where the bolt hole is or whatever but after looking at it again a few different times if it was leaking there would be signs of fluid somewhere near the hole. It looks dry to me.

 

I haven't drained it yet, but there was definitely fluid on the bottom side of the t-case. I think I can see inside the transfer case through the hole. Tomorrow, I'll start the process of pulling it out...

 

I hate to hear that man. But it is the right thing to do. If you like I can send a pic of the t case to my buddys who work for Shep and see what he says if you like.

 

interested in what you find.

 

When I first bought my evo I spent a lot of my time ready on here. Then I started to hear a whining noise when I changed gears and automatically thought it was the TC, with real knowledge, I pulled the TC and dismantled it and took it all to an Evo guy on a box, he took one look at it and said all parts look good lol So I had to put it all back together and get it back in the car. It appears it was noise coming from the gear syncros. So I learned a good lesson on that one. But what I am saying if I can pull it anyone can. Just need to download the manual and take your time.

 

False alarm. I would say it's a good thing, but also frustrating that I spent all day Sunday pulling it out.

I cleaned up the case a bit and as I was cleaning, I noticed that there are multiple un-finished holes similar to what I saw originally. It looks like they are 'planned' voids for the back of the bolts empty into. You can see 3 on the side that mates to the transmission and the one on the other side (facing the passenger side) that I originally saw. I poked a couple of picks around to ensure that they didn't go anywhere (into the rest of the case for fluid or something) and they are completely self-contained voids.

So for future reference these irregularly shaped holes are no problem.

3 on the transmission side

1 on the passenger side

Closeup of the irregular shaped hole left from the casting and machining processes.

 

Well, that is good news. Sorry for being an alarmist on this but the way it was presented certainly looked suspect. So when you probe those inclusions they dont through into the case?

Maybe some type of casting flaw or a designed drain hole for the those mounting stud holes?

 

Not a problem. Better safe than sorry.

Those voids do not go 'inwards' towards any of the internals. I even used a dropper to fill one of the holes with water to see if it drained anywhere. After a minute, there was no change in the water level. My guess is they are intentionally left thin and punched through immediately after the casting process and prior to the machining. This would allow coolant into the back of the hole as the threads are being machined to cool the cast iron and flush the chips out as well.

 

told you... lol.

 

Sucks you already pulled it, but yes. Those holes are normal. And don't leak..