Oil Leak Fix - Attempt Number 4-6 (Somewhere in there), Suggestions on fixing an oil leak issue by the flywheel Options

[netbanshee]

Hey everyone,

Been reading the forums for some years, but haven't had much to say up until now. So Hi, Hey and Hello. Nice to meet you.

I'm looking for some feedback and/or recommendations on an issue my '70 914 1.7l is having. After replacing the flywheel seal a few times to no avail, my father and I are starting to look at a few other options and suggestions.

Here's the car (upon delivery and there on):
http://www.flickr.com/photos/netbanshee/27...in/set-1076179/

Regardless of what's been done so far, the car still manages to leak oil at about a drip every 1-2 seconds out of the bottom of the engine near the flywheel. The oil leak persisted after the car blew an oil galley plug behind the flywheel. Before the car decided to dump most of her oil out in the driveway, I was able to shut the car off and keep things from getting much worse.

We proceeded to pull the engine and tranny, pull all of the galley plugs and threaded in some new ones. We also hit them up with JB Weld for added assurance.

At this point we went ahead and gave the drivetrain and a good once over. We hadn't really pulled apart the car since I purchased it 3 years ago, so no better time then. The car was generally pretty solid up to that point since the owner kept the car in good shape and only put a few thousand miles on the car over the years after an extensive restoration.

We checked the pressure release valves, replaced various gaskets, the fuel lines, relocated the fuel pump under the gas tank, fixed up the hell hole before it got away from us, etc., etc. We then went about replacing the flywheel seal and flywheel o-ring. The 3 shims were in good shape so got them cleaned and lubricated before putting them back in the way they were. We permatexed the outside of the flywheel seal, seated it, bolted everything back up and got the drivetrain back in the car.

After starting the car, we started to get the oil leak I described. Since then, we have tried different flywheel seals (Elring Klinger at first, then Victor Reinz since) to no avail. We made sure that the end play on the crank was between .003 - .004mm and that we seated the seal flush with the case and in slightly different depths so it didn't ride in the previous spot. Also of note, the leak is definitely between the flywheel and the case. There isn't any foul smelling gear oil from the tranny to note.

There isn't any indication that the galley plugs are anything but solid, so our thought was that there was an issue with the flywheel seal. Now that we've replaced it a few times, we're looking at other options.

We were thinking that it might be time to replace the flywheel and bolts. The paperwork I have on the restoration suggests that the original flywheel was machined and polished (dual surface) and we did notice that the flywheel seal we initially removed (don't have it anymore) was white and nothing we had seen before. Possible the seal was a different type?

So, what does everyone think? Any other ideas or suggestions beyond a new flywheel?

Thanks,
Sean (netbanshee)

[netbanshee]

nathansnathan / ppetion,

Talk about synchronicity. I had a conversation about the thicker seals just a day or two ago with my pops since it came to his attention as well. The article is great backup. Will definitely look into it.

Since we're already full bore (yuk, yuk) into the project, I'm hoping that having new bearings, gaskets and the like will be the added refresh this teener needs to keep her reliable.

I haven't driven her since November and we have a '63 Ghia convert that needs a little bit of love before she's on the road too.

Thanks,
Sean

[netbanshee]

Well... a long time, but finally some good news.

I purchased a nice new flywheel recently after my father and I cleaned up the whole case, dropped in new bearings throughout, checked the threaded gallery plugs, etc.

We also had another case that we picked up to compare and source parts from. Inside of that case, we had an older, thicker "West German" rear main seal that was in great shape.

We removed it when we split the second case, pressed it deeper into the rebuilt one (past flush with the outside) and did the rest of the assembly. After about 25-30 minutes of running the car, not a drip in sight. (IMG:style_emoticons/default/biggrin.gif)

So, all in all, it does seem that the thicker rear main seals do provide a better seal than the standard ones. On top of that, making sure that the flywheel is in great shape and that the seal is pressed in farther than flush with the outer part of the case does make a big difference.

Since we ended up turning this into a bigger project by pulling apart the whole drivetrain, we could have affected other things in the engine, but nothing as directly as the last steps in terms of the oil leak issue.

Seeing that aside from the car being in storage, I haven't driven her in 11 months total, I see where this upcoming weekend is heading. (IMG:style_emoticons/default/driving.gif)

Anyone curious about any other observations or anything from the whole process?

Cheers,
netbanshee