Hey gang, After a recent S5TII rebuild, the engine has been pooling oil at the joint between the rear rotor housing to iron near the oil filter. The oil filter pedestal orings were changed and the leak remains, so presumably something's wrong with the oring at the upper dowel pin interface. I was going to let it leak, but now oil is migrating to the clutch plate causing slippage, so the engine has to come out (again).
The question is: what are the chances that I can remove the rear iron only with the oil pan, UIM, and turbo manifold in place, fix the oring, and reassemble the keg without causing water seal and oil pan leaks. I really want to avoid unstacking the entire keg to fix this. Anyone have experience successfully removing the aft iron?

 

Yes, been done before. Well, probably want to remove oil pan.
Probably easier to pull the engine and do this than try to drop the trans and do this from under the car.

Clamp all the other housings together before loosening the tension bolts for best results.

Check rear side housing carefully for crack at the upper dowel area, this is what usually causes the oil leak in the area you mention.

 

Didn't Buckey do this before?..
I remember a thread where a guy had wired the rest of the engine together with cable,etc to prevent the parts from moving.

 

i've done it plenty of times, but i certainly wouldn't follow buckey's advice.... all you need is a few wood clamps from the front iron to the rear rotor housing, snug to keep the stack from coming apart.

 

I appreciate the comments. Here are my thoughts:

Why's that? (I'd really rather not)

That's the plan, the devil's in the details. I'll figure it out once I pull the engine.

Agreed, upper dowel land cracking is a common problem and something to check, but seems unlikely in my case since my new aft iron has the reinforced dowel boss.

Yup, there's a thread like this but 1) it's not what I'd call a well engineered solution and 2) the pics were on Photobucket, so nothing to see now.

My main insight is that the rear rotor side-seals will be uncompressed so the sole force to the aft rotor housing will be one set of water orings. The main force to resist with clamps is between the front and center irons.
I won't be able to start this project for a few weeks so it may take a while to find out.

 

So you don't get the dreaded oil pan leaks once you are done. Its just going to be harder to get a good seal between the rear iron and the oil pan when you are sliding the rear iron onto the dowels and scrapping any sealant off the oil pan in the process (ie, the rear side housing can only be guided straight onto the dowel pins, no angling to get it on and sealed against the two perpendicular surfaces without displacing the sealant).

I have done a couple front covers in car and once I saw what I was up against putting the front cover back on with the oil pan in place I resigned myself to doing oil pan and front cover.

I have cracked reinforced rear side housings, intermediate housings and a front housing, but never had a leak at a dowel pin o-ring- so, what seems unlikely is relative in this case.

 

****, you're right on both counts BLUE.

 

don't stop at the center iron then, there is studs on the exhaust in the rotor housing and if its a S5 a knock sensor thread on the other side, or if you have something to thread into a spark plug hole you can use that as an anchor point as well. or if once you removed the oil pan you can use a flat plate with a few holes drilled into it down there, there's also the emissions rack bolt holes on the top of the rotor housing.... lots of places and ways to clamp it all together.

you don't have to go crazy with the clamping force, just trying to keep the sandwich snugly together.

 

OK, I'm ready to remove the rear iron. Here are some pics of my approach for holding the stack together. Two strips of Garolite at the oil pan flange and a chain from the front iron to rear rotor housing. LIM and turbo remain installed since I wanted to keep the engine as fully assembled as possible. All this just to check the upper dowel o-ring since I never made enough power to crack the beefy late production dowel land. So is this tactic going to work?

Oh, and removing a perfectly sealed oil pan was painful.