threesticks

Well my '86 951 has decided that it wants to wear its engine oil on the outside of the engine.

I changed the belts, rollers, seals, water pump and coolent hoses and every thing went well. I had never done this job before and every thing seemed to go well. There were no leaks for the first 1000 miles.

Then last saturday while I was driving home I started to smell burning oil. I pulled over to the side of the road, stopped and got out and looked under the car and found oil comming from a small drain hole on the belt cover. Checked the oil level and it was still near where it was when checked last.

Last night I finaly had some time to tear into it and found that the oil is comming from the lower balance shaft. Not from the lip seal but between the seal sleeve and the balance shaft. So the belt pulley was dry on the back but wet with oil on the front where the bolt and retainer are. Of course the belts are soaked with oil and will have to be replaced.

I know that I installed the fiber seal (small clear plastic washer) but it looks like that is were the oil is sneaking out.

Is this common? Is there anything that I should look for before I put everything back together? Maybe I did something to damage the fiber seal. Is there a method to installing these?

I really appreciate the help.

Steve Frew

threesticks

Pardon my bump please!

Steve Frew

Rod in Orlando

You might want to verify that the tension on the belts is not to high which might cause the seal to wear againt the shaft differently.

dgz924s

3sticks, Does the seal have metal races? If not, consider a different seal. I just got an education on seals and was told to get the non fiber type. But to get the real info call Dennis at Zims he can explain the seals more accurately! <a href="http://www.allzim.com" target="_blank">www.allzim.com</a>

D <img src="graemlins/burnout.gif" border="0" alt="[burnout]" />

WillyC4S

Steve,

I've got a similar problem and have performed the same maintenance items you did and gotten similar mileage before noticing the oil leakage.

My leakage is from the same general area as yours as well as from the crankshaft area. I'll have to take the covers apart to find out which of the 4 seals I put in is causing the leak. I think it's the crankseal; that one's a bitch.

Please keep us posted since I'm in the same boat.

Thanks,

*****

michael2e

I recently had a similar leak on my lower BS. Couple potential problem areas as far as I know: First, the wafer thin clear seals are easily torn when sliding on the shaft. Second, to get a good seat on the orange rubber seal it is advised to lube the rear surface and then it's necessary to press it in evenly with a large socket (actually, Porsche makes a special tool for this). Requires a bit more than just thumb pressure to seat it. The other thing is that the aluminum sleeve that slides over the shaft can wear in higher mileage cars thus exceeding tolerances and allowing oil to get through. These are about $20. Hope this helps.

Dave951M

One other area to check out. Make sure that the seals are the correct ones with the correct rotation. The balance shaft seals are left and right. In the three seal kits for a 951/44 that I've examined, 2 had wrong seals in them. Don't trust that the kit was packed correctly and also verify that you have the correct seal in the correct place and that the rotation is correct.

threesticks

Update: I found the cause of my oil leak at the lower balance shaft.

I disassembled the balance shaft housing and replaced the seal, seal washer, and the seal spacer and reassembled the whole thing including retensioning the belts. I left the covers off so I could watch and verify that I made an effective repair.

I started the engine and almost immediatly oil began comming from around the bolt that holds the pully on the balance shaft.

Pulled the balance shaft belt and pully and noticed that the retaing bolt had oil on its threads. I then made some plugs for the inlet and exaust and pressurized the motor with 10 psi air. I then climed under the car to watch and listen for a leak. I found it. It was coming from the center of the balance shaft. There is an aluminum plug in the center of the shaft. I haven't seen a schematic for the oiling system but it looks like the oil travels through the center of the balance shaft and the plug is there to stop the oil. Kind of like the crank shaft.

So now the problem is: How do I stem the flow.

I guess the best soulution is to pull the balance shaft and have the plug removed and replaced. The next alternative is to seal the threads on the shaft.

I work on turbine engines for a living and have access to some effective sealants. Some of the engines I work on have a simular set up and we use a certain grade of Loc-Tite and Loc-Tite primer. We never have problems with leakage in that application. The bolt would still be removable with hand tools and would seal to about 150 psi and 400 degrees.

I'm not sure. Do any of the "Gurus" have any experience with this? Your wisdom filled replies are greatly appreciated.

Steve Frew

WillyC4S

Steve,

I've never heard mention of the issue you discovered w/ oil leaking from the center of the BS. I'm going to check this on mine also when I take it apart.

This is something that I would never have found or even guess could happen. Good detective work!

You also mentioned that the crankshaft has a similar setup. So this implies that there's also a potential for an oil leak from the bolt there as well?

What about the camshaft? I remember reading that Loc-Tite was recommended to be put on that bolt, but I left it off seeing as how much of an issue it was to remove the first time around. Never thought that the Loc-Tite was going to be used as a sealant to block oil seepage.

*****

WillyC4S

Steve,

Any news on your oil leak? I'm probably going to dive into mine this weekend to find out the problem. Was hoping to see if your LocTite sealant worked or not to fix your leak coming from the pulley bolts.

Thanks,

*****

threesticks

Hey *****:

I got the car back together monday night using Brown Loc-Tite. It is an hydraulic sealant and workes well on the turbine engines here at work.

Drove it for about 30 minutes monday night and drove it to work tuesday, wednesday and today and as of this morning no oil leak. Knock on wood.

It should work until the next belt change.

Good luck.

Steve Frew

WillyC4S

Steve,

Glad to hear that your fix worked. I've got to check mine to see if this is the same issue. Better to re-seal the bolts than to re-do the seals ....

I'm going to be using something called 3Bond 1311 to seal the threads. It's a white silicon-based sealant that I was told was "aviation-grade" sealant. I've used it on the water pump, the oil filter housing stand, the rear cam housing plate (w/ the engine hook loop). So far no leaks.

Have you ever heard of this stuff? Cost me over $15 for a 3-4oz tube.

Thanks,

*****