GodSpeed

Updated see post #4
I have a pretty bad oil leak coming from under the intake. I cant see where its coming from but I did a few searches and it seems the balance shaft seal is the most likely. I know its not the cam housing. And the head is dry.
Question:
Where is this seal ?
Anyone got any pics?
Anything else I need to order other than the seal?
Anything I should know before hand?

TIA,
Dan

p.s. I will also be replacing the AOS seals while the intake is off.

KuHL 951

There's a round fat O-ring that attaches to the aluminum cap at the rear of the BS housing. If you can feel that cap move the seal has shrunk like they always seem to from heat and age. This pic shows the round cap at the rear of the other housing but the cap is the same. See if it feels loose.

sweet9fortyfour

Hope yours goes better then mine.
https://rennlist.com/forums/924-931-944-951-968-forum/363098-why-do-those-quick-jobs-never-turn-out-that-way.html

had the wrong link

GodSpeed

Ok so I can spin the cap freely with my hand shoved under the intake. The seal thats leaking is right next to the ISV. I already looked on clarks but im still confused a bit.

Will someone explain what exactly needs to be done to fix this?
I will pull the intake but does the balance shaft housing need to be removed too?

Im trying to get this done asap, so quick replies are appreciated.

TIA
Dan

Weston

I used to have the same problem on my race car... both balance shaft rear plugs were leaking at 5000+ RPM, resulting in a coat of oil all over the bottom of the car, and plenty of white smoke when it got on the exhaust (which it did a lot).

There is a simple and cheap fix for it though... Go to an auto parts store and pick up a tube of Permatex Ultra-Grey (more commonly known as Hondabond), then smear a bunch of it all over the edges of that plug to seal it up, and let it sit overnight. Of course, you'll want to clean the area first, and the upper balance shaft is a lot easier to deal with if you first remove the intake manifold. When it is done drying, the plug should no longer move or leak any oil at all. This stuff has excellent sealing and adhesive qualities, and it's the only thing that I've ever had good results with when it comes to sealing a leak from the outside. I also used it to replace my rear cam tower gasket (the cork one that's notorious for leaking), and a few other things on my car and other 944-Spec race cars.

GodSpeed

I would like to replace the seal instead of using something like handa bond, unless the fix is to involved.

What is involved in replacing this o ring/seal on the plug?

sweet9fortyfour

Basically you just remove the balance shaft cover and replace the o-ring. On the early cars the a/c bracket is in the way. Went out mid post and looked at spare 86 engine and the bracket is the same way. Pretty straight forward.

GodSpeed

Ok so I searched a bit and Im going to just remove the housing and replace the seal.

What parts do I need to buy to do this?

sweet9fortyfour

All that's there is the o-ring. Probably supposed to use 574 loctite to seal housing to block. I used orange Caterpillar sealer.

tomrc

I'm in the same boat, my car will not hold oil for anything. Anyway I think I'll order the parts and do both balance shafts this weekend, full seal. I'll probably remove the intake, the condenser, and alternator. I already did the front seals, belts and water pump less than 1k ago so that's all new. If you don't do yours this weekend I'll let you know how it goes.

KuHL 951

Even with new O-rings on the new engine I'm still going to use some Yamabond outside of the seal area for cheap insurance. That seal design is poor IMO. Since you will working with the engine in place be sure that the sealing surfaces on the cover are surgically clean before using the Loctite 574 or it wont cure correctly. Hopefully you don't also have to do the lower BS on a 951, that one is not fun at all.

ELLSSUU

If you're taking the cover off you need to replace the front o-rings too! They're easy but don't forget them. Also as was already said smear the back donut with some type of good sealent as was recommended to me by Ski and a few others. I used Permatex Gold and my donut looks like a gold disc now.