My case does not want to separate

jwasbury · 09-22-2009, 06:24 PM

Doing a rebuild on my '79 930:

Jacob's rebuild thread

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.

dtw · 09-22-2009, 07:32 PM

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.

Flat6pac · 09-23-2009, 04:17 AM

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

jwasbury · 09-23-2009, 07:14 AM

Quote:

Originally Posted by Flat6pac

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?

CliffBrown · 09-23-2009, 08:07 AM

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

Use a BFH and use it lightly front and back.

colescrogham · 09-23-2009, 08:40 AM

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...

jwasbury · 09-23-2009, 09:18 AM

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.

Jesset100 · Jesset100's Garage

Intermediate Shaft End Cover

sand_man · 09-23-2009, 02:54 PM

As we discussed by phone, earlier:

case splitting tool

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

jwasbury · 09-23-2009, 04:28 PM

Quote:

Originally Posted by sand_man

As we discussed by phone, earlier:

case splitting tool

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.

jwasbury · 09-23-2009, 04:42 PM

I should add a few data points to this thread. I am a lightweight at about 140lbs. This is my BFH

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?

CliffBrown · 09-23-2009, 04:44 PM

Show us where you're hitting the case.

jwasbury · 09-23-2009, 05:18 PM

Quote:

Originally Posted by CliffBrown

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.

JFairman · 09-23-2009, 05:34 PM

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

jwasbury · 09-23-2009, 05:43 PM

Quote:

Originally Posted by JFairman

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

My worst fear

CliffBrown · 09-23-2009, 05:49 PM

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.

TibetanT · TibetanT's Garage

Subscribing...

bpu699 · 09-24-2009, 09:29 AM

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?

jwasbury · 09-24-2009, 10:43 AM

Quote:

Originally Posted by bpu699

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:

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

Fast Corners · 09-24-2009, 11:17 AM

Wow, that is just too damn funny!