My case does not want to separate
 

Doing a rebuild on my '79 930:

http://forums.pelicanparts.com/911-930-turbo-super-charging-forum/492267-jacobs-rebuild-thread.html

I'm down to the 'fun part' trying to separate the case halves. In the 'Case Separation' section of Wayne's book, it says "the case should immediately begin to separate" upon tapping with a mallet. Well, that is not what's happening for me. Towards the bell housing end, I think the parting line is separating just a bit...about the width of a mosquito's pecker. On the front side of the engine, I see no evidence of success. The book also uses the term "tapping." Since tapping was not yielding any result, I've tried some whaling as well. Still no go.

I've double and triple checked that all fasteners have been removed. Counted 22 13mm nuts (correct amount per the book), 11 through bolts, 2 15mm nuts under the oil cooler and the super-secret nut inside the chain housing.

I have a couple of theories:

1) Separating case halves is not as easy as it sounds in the book.
2) I need a bigger BFH, like a RBFH
3) Case has been apart before and was re-sealed with some ultra strong 3M adhesive like what dentists use to bond crowns to teeth.

Any ideas folks? I am afraid to continue beating on the case unless I hear that this is not unusual.

Hang it up for the night. Wash up, go to bed. Come back tomorrow.

Ok, you're back? Go around the case and make sure you removed all the aluminum crush washers. They can do an amazing job of hanging up on the studs when they have been over-tightened.

Now, go around the perimeter with your hands and eyes, looking for remaining/forgotten nuts. Forget the nut count. Nuts under the fan strap area? By the breather orifice? Under the flywheel? Bottom of case, nuts facing oppositie direction than rest of nuts? "Death nut" that secures the intermediate shaft bearing saddle (not on perimeter...sorta out in space by itself)?

You already mentioned the chain housing nut and the cooler nuts, guess you're good there.

If you really got all the fasteners, get a length of soft wood and use it as a drift. Plenty of flanges and meaty areas on the case to use it on. Give your hammer good smart raps against the wood. Move around the case in a circle, so you don't get one side cocked up and frozen.

how about the 10mm inside the left chain area inside the case..It has to be a fastener somewhere..behind the oil cooler?
Should just tap apart
Bruce

That's the "super secret" nut I mentioned. Removed from inside the case where the chain runs. It was an M10 17mm nut in my case. Both 15mm acorn nuts removed from the oil cooler area. Before I posted last night, I went back to the garage and quadruple checked with the book in my hand and verified each of the nuts in the photo had been removed on my case. Is there some 'bonus nut' that isn't in the book? Anything specific to a turbo case that isn't included in the book?

Make sure to also remove all the washers. They can make separation difficult.

Use a BFH and use it lightly front and back.

Case
 

2 things I regularly forget: the 2 bolts with nuts (not studs) that have the nuts actually going the other direction than the studs on the bottom at each end of the later cases, and the cover for the intermediate shaft that must be removed before the case can be split in earlier ones.
Another great one to forget is the nut for the long stud by the oil pump. Its located in an odd place on the left side not on the perimeter. They tend to leak and have seen a few almost disappear with a lump of crud over the years.
I don't think the case halves are going to leap apart, but you should be able to get some separation without whaling...

I'm pretty sure I got all the sneaky nuts on the back side and the one for the oil pump (it's towards the bottom, underneath the cylinders but not on the perimeter).

I will go back and quintuple check that all nuts are removed.

I did have some stuck washers. Started the attempted separation with them in place, and then figured that they could be hanging things up, so I removed them with pliers. Will check again for stragglers.

We'll have another go at it tonight.

Intermediate Shaft End Cover

As we discussed by phone, earlier:

http://forums.pelicanparts.com/911-engine-rebuilding-forum/167040-case-splitting-tool.html

Obviously make sure all of the required hardware has been removed....

Thanks for the link Jeff.

After a stimulating day at the office, a good deal of which was spent obsessing over my rebuild project, I took another crack at this case...literally.

I would love to tell you all how I found a fastener (or intermediate shaft cover) that I previously overlooked and post a nice photo of my crank and oil pump, but I can't.

After checking to insure I've removed all the necessary hardware another 12-15 times, I began beating on the case with my mallet for another half hour...

Looks like my case may be 'special'

That case splitting tool looks like it might be the ticket. I'm intrigued by Henry of Supertec's method, although I don't quite understand the detail and how its supposed to work.

I should add a few data points to this thread. I am a lightweight at about 140lbs. This is my BFH
http://forums.pelicanparts.com/uploa...1253752734.jpg

Perhaps my concept of beating on the case is not enough force? Maybe I need a bigger hammer, or maybe I should put on some weight?

Show us where you're hitting the case.

I've done the "4 corners" per Wayne's book. I've also hit it around the entire perimeter of the parting line in an effort to break the seal, even though the force of the blow was not in the direction of separating the halves.

sounds as if someone used JB weld as a case sealant on it.

My worst fear:eek:

Put the acorn nuts back on the studs under the oil cooler and the nut back on the stud under the driver's side chain case.

Try hitting the acorn nuts and the front stud (nut) with your hammer alternately. Use an old socket extension or brass drift to reach the front stud.

Subscribing...

Just a thought...

If its been sealed, or glued, or JB welded... then a propane torch should seperate it...

Even JB weld fails at 600 degrees or so, right?

So it says on their website...I checked it.

I've got a plan for a splitting tool similar to what was done in the 'case splitting tool' thread link posted above. I just can't take this prehistoric $hit any longer:

http://forums.pelicanparts.com/uploa...1253817634.jpg

I'll also have my propane torch handy...stay tuned.

Wow, that is just too damn funny!

update - some successful progress
 

I made myself a case splitting tool using a craftsman gear puller I already had and some pieces of scrap metal.

http://asbury.smugmug.com/photos/660000824_AY89A-L.jpg

I put some torque on it and left it to sit for a minute or two when I heard a loud CRACK! It was the sound of the seal busting open (finally). The sealant is really bonding these case halves together. At least I have the top side parted:

http://asbury.smugmug.com/photos/660001148_r94GA-L.jpg

The bottom side is still sticking fast. Got out the hammer and started beating again, but I did not have much time to work at it this evening. Have a look at the sealant in this picture. I'm guessing that this is not factory?

http://asbury.smugmug.com/photos/660001547_CVUGY-L.jpg

It looks like Permatex Aviation sealer but I have never seen it stick like that before!

uh oh.. the grey stuff does look like epoxy...

If it's soft it's silicone.

all the "aviation #2 non hardening" gasket sealer I've used is reddish brown and it does pretty much harden after time and heat cycles.

Most defintely not silicone. The stuff is hard as a rock. It could be this aviation sealer you speak of...the color does appear to be reddish brown, especially where you can see it inside the case (such as under the breather cover).

So did you have any idea that your case had ever been apart, before?

Nope.

Based on info I have, my car has been through 5 owners before me. I spoke with the second owner who had the car the longest (from about '81 - '00, nearly 20 years.) I specifically asked if any major work was done, and was told no. He is a wealthy guy (CEO of Chaparral boats) but I can't imagine he would forget writing the check for a full rebuild. I also spoke to the guy who bought it from him (3rd owner from '00-'03) who too said nothing major was done. I have invoices from this period of the car's life forward. Unless these people are lying (and why would they when they are several owners removed from my purchase) or are forgetful, it suggests that the engine was rebuilt within the 1st couple years. Strange.

I use a small turn buckle on the studs on front of the engine, and another on the studs in back of the engine. About $3 at home depot. Good luck!

success at last
 

The case is apart!

I made a second splitting tool to get the bottom side cracked open. Just like the topside, I put some tension on this and waited for a minute before the SNAP! of the sealant breaking loose.

http://asbury.smugmug.com/photos/661703244_zohJR-L.jpg

Here's the obligatory pic of the crank and oil pump. I found some of the hardened sealant on the intermediate shaft gear...whatever that stuff is, its tenacious.

http://asbury.smugmug.com/photos/661..._gerrt-L-1.jpg

Now back to your regularly scheduled rebuild...

Great job! Keep up the good work.