OK, What's the Trick To splitting case Halves

GolfBravo · #1 03-28-2006, 10:14 PM

The Lycoming Overhaul Manual states use of ST-122 Pressure plates. I've searched the net and no one seems to sell them. Nor, use them from the few blerbs I've found. I haven't missed any fastners, and the block of wood and dead blow doesn't seem to be budging the SOB.

Tom McCutcheon · #2 03-29-2006, 03:09 AM

I can't answer your question about splitting the case. However, recently someone I know had to do it and they were told emphatically to be sure not to let the lifters fall out when splitting the case. And, how important it is to make sure each cam lifter goes back into the same position. He was also told that by not putting the lifters back into the same position the engine would last maybe 25 hour till failure.

Not all is lost if you do get them out of order. The fix is to have both the cam and lifters re-ground (much less expensive than replaced).

Of course, if the cam and lifters are going to be replaced anyway then none of this matters.

mahlon_r · #3 03-29-2006, 05:09 AM

The procedure for splitting the case differs depending on the style case you have. Is it wide deck or narrow deck? If wide deck, does it have anchored thru studs or body fit thru studs?
Good Luck,
Mahlon
"The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at you own risk."

GolfBravo · #4 03-29-2006, 09:20 AM

It's an Wide Deck O320 E3D. The Fwd and Center Thru Studs are not fixed. Where as the aft ones are fixed.

Carr · #5 03-29-2006, 09:34 AM

Did you get the castle nut behind the Cam gear off?

B Carr

mahlon_r · #6 03-29-2006, 09:46 AM

If you have body fit thru studs then you don't have dowels and you don't need the special case splitting tool. Make sure you get all the nuts off including the one Mr. Carr mentioned that is behind and under the cam gear. Pull the nose seal out of it's recess. You should then be able to get it apart with very gentle prying on the non parting surfaces of the case along the bottom and rear accessory portions.
Good Luck,
Mahlon
"The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at you own risk."

GolfBravo · #7 03-29-2006, 09:48 AM

I'll give it a shot tonight. I do have the castle nut off from behind the camshaft gear.

Allen Barrett · #8 03-29-2006, 09:58 AM

If as you say all perimeter bolts sump bolts and case bolts (except the back 2 of course) are out, a simple tapping on the alternator pad and around the accessory area should be sufficient to get the cases started apart. There are 2 7/16 dowels in the case that 'sort of' align the cases, once you are past these two dowels, the cases will pull apart. Something I have seen happen before is someone will use a dead blow and whack the nose seal area. DON'T DO THIS. if you do, I'm taking bets on how many times you hit it before the slinger gets it! Also be careful about getting the nose seal out, especially if the crank will not be reworked. It's real easy to scratch the seal area and could cause future leaks.

Allen

GolfBravo · #9 03-29-2006, 10:12 AM

I'll give it a try. I've looked and relooked to ensure all the fastners are out. This engine is out of a 73 Cherokee with only 2108 TT and has never been apart. Just probably being stubborn since it's been together for 33 Years.

GolfBravo · #10 04-06-2006, 10:09 AM

I spoke with an A&P buddy of mine who suggested an LPS Product, PreSolve which is actually a Penetrating Cleaner/Degreaser. Well the local Industrial supply store didn't carry that particular LPS product so I looked at what else they had in the penetrating oil department. I found Aero Kroil which is made by Kano Labs. They start their claims with a money back guarantee followed by stating their product is,

"an industry proven penetrating oil that has no equal. Quickly loosens
rusted nuts and bolts - frees frozen shafts, pulleys, etc. Penetrates to 1
millionth inch spaces, dissolves rust, lubricates, cleans and prevents rust.
Displaces moisture. The oil that creeps."

Figured with a claim like that, maybe it'll help this 33 year old O-320. So, I sprayed down the seam on the case, all the bolt holes a few times over a couple hours. One tap from the dead blow and there it split.

Needless to say, I was impressed.
I spoke with my Dad about this product. He's a NDT inspector for Lockheed Martin. He said it sounds similar to the stuff they use for doing penetrant inspections, less the ingredient that glows of course.

If you ever have a stubborn assembly, bolt, etc. I suggest giving this stuff a try.

www.kanolabs.com