4l60e 2-4 Servo Cover Stuck

This week on when "while I'm in there" goes wrong...

This weekend I decided to attack the leaking trans cooler line on my 95 Chevy C1500 and figured 'while I'm in there' may as well do a fluid and filter change as well.  So then I figure, since I have to drop the pan anyways, 'while I'm in there' I may as well throw a Transgo HD2 shift kit at it as well for $80.

Took my time pulling the valve body and other bits inside the pan, which all went smoothly enough, but once I got after the 2-4 servo things went south in a hurry. The circlip was a bear to remove and was severely mangled in the process, and now the cover shows no signs of wanting to budge from the case - zero movement inward, outward, or rotationally and I'm no where close to being able to access the o-ring and pull that out. I've picked crud out of the groove and cleaned it with brake cleaner, pried against the body trying to push the cover inwards, tapped it with a hammer, pried with a screw driver, pulled and twisted with vice grips, channel locks, and a pipe wrench and nothing, it's just frozen in there.

Anyone have any ideas? Ever had this happen before?

Probably going to just keep soaking it in PB Blaster and prying at it some more with the crow bar over the next few days. I've also considered fabbing some kind of massive c clamp like device to span the case and press on it. Also saw it suggested that if you get the rear wheels up in the air and run the trans through a 1-2 shift it'll pop right out, so maybe I just carry on with the rest of the install and try that once it's back together? Smart thing might just be to bag the stupid shift kit, but I'm not quite at that point yet.

The one i did sucked.  Corroded in place, beat on it, i think i finally got a pipe wrench on the nub in the center and got it to start spinning enough to work the crud out and then get it out.  This was all on the stand too,  not under the truck 

Biggest brass hammer you can swing. It's going to fly out anyway when the cover comes loose.

You have to push the cover in while removing the retaining ring if you don't want to damage things, so that explains that. I never ran into seriously corroded ones down here so generally what i did was just grab the nub in the middle with big channel locks and rock it up and down to get it moving. If you stick sufficient padding in front of the cover to keep it from shattering upon flying out you might be able to 'eject' it by 'air checking' the servo from the valve body side. 

Yea, trying to do this with the trans still in the truck isn't helping matters. My hammer swinging room is pretty much nil. I might be able to get a decent shot at it if I pull the passenger side header off and drop the transmission down as low as it will go (cross member is already off to access pan bolts), but I'll probably bag this whole stupid idea before I go as far as dropping the trans. 

I'm liking the 'air check' idea, that might be the ticket. New cover is on the way just in case this one gets butchered. 

Pneumatic hammer/chisel with a flat "planishing" bit.  Buzz on it a bit.

... without your face in front of it.

Reminds me of the time I was replacing a clutch on a John Deere "G".  I had the worlds largest 3-jaw puller on it and it wouldn't budge.  Let it sit overnight and the next morning I went to HF to get one of those pneumatic hammers.  I wish I had a video of it.  I came home, hooked up the air to it, and went over to look at where I should hit it... when it chose right then to pop... on my cheekbone.  Don't know if I went out completely, but there is a period of time that is missing between the pop and when I got up off the floor.

In reply to Curtis :

Air hammer is another good idea. My favorite tool that I always forget I own. I'll do my best to stay the hell out of the way if/when I ever get the thing to pop.

So i gave it a few quick blasts with the air hammer to no effect, then quickly moved away from that idea for now in fear of damaging something. 

Anyone care to explain exactly how I go about air checking the servo? 

In reply to Furious_E :

You find the hydraulic feed for the servo and apply 125psi of shop compressed air to it.

So I shot some air into what I think was the correct orifice last night (small port maybe 3/16" in diameter on the bottom of the round part the servo fits into, angled towards the front of the trans - can't find a decent pic at the moment.) Could definitely hear some movement going on inside the trans, but the cover remained stubbornly in place. 

I think at this point pulling the trans and dealing with this on the bench might be the best option. Ugh. 

So I made some "progress" today. The good news is I got the trans dropped and with a few good whacks from the brass hammer the cover finally budged. The bad news...

...the nipple thing broke off. I blame the air hammer, or more specifically not using a flat enough attachment. I think I can at least figure out a way to pry it off  now.

That doesn't seem like bad news to me because i 100% assumed you were in it for a new cover at this point anyway. Just looks like progress to me! 

And at long last, victory! What a bastard of a job that was.

New cover was already ordered and delivered, as I figured the old one was bound to get butchered. The issue was with the nipple broken off I had nothing to grab onto, nor was there much I could pry on, as the case is pretty thin and weak in that area and breaking that would nave meant a whole new level of cluster berkeley. Finally got it by getting a screw driver under there and using the 4th gear piston as a fulcrum.