case bolt/ oil leak

[the911Tprocess]

Hi All,
I've solved most of my oil leaks which has been a real treat. There are only two remaining leaks.

The first one is coming from a case bolt, picture # 1. I put a wrench to it and it is loose! What is the torque setting for this bolt?

The second leak is coming from the front of the engine, I am not sure what this is called but I checked and it is tight. this there a gasket that I can replace?




Any assistance appreciated.

[equality72521]

The second one has an metal o-ring seal, you can just see the edge in at the top-right of the screw in the picture. Don't know about the first one.

[the911Tprocess]

One more thing, should the case bolt in the picture pertrude so far out of the case, I checked to see if the bolt itself would turn and it doesn't so I suppose that is good.

I'm asking about torque setting since I am assuming that if I retighten it the leak would stop.

[equality72521]

It does seem to be sticking out more than it should. More than mine. It's also shinier like it might have been replaced and you can see the blue from the nylok nut as well. That doesn't look original.

[cgarr]

Thats a stud that often pulls out of the case, it could be pulled out a bit, is the nut bottomed out on the stud?

[billybek]

Case bolts,(M 10) 26 ft/lbs.
Main journal nuts (M 8) 18 ft/lbs).
Taken from Bently, but no order was given for torquing. I would be a little hesitant to tighten only one without checking the others.

[billybek]

Originally Posted by cgarr

Thats a stud that often pulls out of the case, it could be pulled out a bit, is the nut bottomed out on the stud?

Great point!

[cgarr]

Here is a pic of the bolt, one end has about 22mm of threads while the end that goes into the case only has 15mm of threads.

[john walker's workshop]

remove the stud, which has pulled the threads out of the case, run a 10X1.25 tap down about an inch or so and use a short 10mm bolt with an aluminum sealing ring. the hole is the proper size already for the 10mm tap. just snug enough to seal. no damage is done with this temporary fix.

[Grady Clay]

STOP!

Don’t turn the case bolt any more. I suspect it is pulling the threads in the case. Just let it leak until you have the case apart someday.

That stud straddles the jack-shaft bearing. It normally protrudes about 12 mm proud of the case. Your image appears to be somewhat more. When ‘pulling’ the stud won’t turn, it simply ‘pulls’.

Best,
Grady

[the911Tprocess]

Grady and John,


Well, the stud did pull out of the case, it's sitting in my hand. Before I did anything I grabbed it and it seem to wiggle so I thought well if it wiggled its done.

When tapping, is there a concern for any metal shavings falling into the engine?

Here is the stud that pulled out. Take a look at the threads, do you think the PO had this problem before?



Will get a new stud before attempting this.

[Gunter]

Originally Posted by the911Tprocess

One more thing, should the case bolt in the picture pertrude so far out of the case, I checked to see if the bolt itself would turn and it doesn't so I suppose that is good.

I'm asking about torque setting since I am assuming that if I retighten it the leak would stop.

Judging by the pictures, this engine hasn't been rebuild but is in need of it?
What's the mileage on it?
What are your plans for a rebuild?

Too many people disregard correct torque and overtighten fasteners resulting in damaged threads.
"If it leaks, just tighten more" is often the wrong approach; replacing seals or crush washers is more appropriate.
Wayne's book on engine rebuild would be a great help to you.

[the911Tprocess]

Gunter,
yes it needs a rebuild,
yes I have the book
and no I didnt even consider tightening the bolt. I used my fingers and realized that it was loose while the bolt itself was tight. Not a good sign at that point.
Thanks for your advice.

[Gunter]

JW says do not re-use the old case bold or get a new one.
What he means is to ignore the case bolt for now; just plug the hole by cutting a new M10 thread on the outside of the case for a short bolt plus Alu crush washer to prevent it from leaking.
Get the M10 x 1.25 taps; they come in a set of 3.
You start with the #1, then #2 and the last one #3 is the bottom tap. Only about an inch deep for a short M10 bolt with thread-locker if you like.
I suggest you put grease on the taps before going into the hole so that any dirt or chips will stick to the grease.

Later, with a rebuild, the damaged thread inside can be fixed with a case-saver type plug similar to HeliCoil.

[john walker's workshop]

it's a blind hole, so no chips will get into the engine if you miss a few.

[the911Tprocess]

Gunter, I'm sorry I am really thick sometimes, I am just trying to understand your advice and John's. Before I touch anything and create more issues.

What I thought John was saying was to remove the stud from the case. That was easy since it already had pulled out enough that it came out using my figures. See picture.

Then I thought John indicated to use a 10 x 1.25 tap, put it into the hole of the case and re tap the existing thread that holds the stud on the inside of the case.

Then put the stud back into the hole (use thread locker on the stud before putting it bac, thread it enough into the newly threaded hole on the inside of the case so that some of the thread of the stud that appears on the outside of the case is enough to use a thinner bolt with a alumium washer.

I think that is what I understand. Please correct where I'm wrong.

thanks again.

[the911Tprocess]

All
I think I finally got it.

What John and Gunter are saying is make a thread in the exisiting whole in the case. Plug the hole with a bolt with an aluminium washer.

Boy am I thick sometimes.

[billybek]

No, that isn't being thick. It is hard to read about what you should do sometime without someone pointing and telling you..
It looks like the guys who know how, got you to understand how. That is what it is all about..

[Gunter]

Because the area is tight with no room to turn the tap, use a small wrench that just fits on the square at the end of the tap.
You want to tap in as straight as you can, so, take the #1 tap which has a pronounced taper to almost self-align. Start the tapping by pressing down on the tap while at the same time turning with the wrench. Once it starts to bite, it'll eat it's way into the hole but keep pressing down for the first 2-3 threads.
Take your time.
Reverse after every one turn just a little to break the chip; it'll help!
Avoid cross-threading when using #2 and 3; start them up carefully.

To get a good seal, the thread should be exactly perpendicular to the mating surface so the Alu seal is squeezed evenly all around.
In addition, use some sealing goo.

Have fun.

For the other leak, maybe next time you change oil you could take the plug out for a re-seal?

[the911Tprocess]

thanks Gunter,
I will post pictures after I,m finished.
Appreciated everyone's help.
A bit of a scare here but it looks like all will be well.