Rear Main Seal

[cannonfodder4j]

Hey everyone! i recently bought a 1985 VW Vanagon which had a pretty bad oil leak. I researched the leak and found that it was a busted rear main seal. I spent the last two days in the shop pulling the transmission and accessing the seal. It was busted so i replaced it. The problem is that when i put it all back together and started it up, the van was leaking stronger than ever. Does anyone have any suggestions? Im getting really desperate. Thanks

[Cold Steel]

try this to see if it helps.
http://www.thesamba.com/vw/forum/viewtopic.php?t=412077&highlight=
did you counter sink the seal?
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91 Syncro
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[peasant]

Theres a good boston bob video tutorial of replacing the rear main seal. Havn't been able to find a good recent link though.

edit: people also say the Sabo seals are the best too.
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89 wolfsberg weekender carat
89 Westfalia

[cannonfodder4j]

I had another mechanic check my work and he used the old seal to hammer it in flush so i really dont know what else i could do. I couldnt find the Boston Bob link either

[Wildthings]

You are going to have to pull the engine again no matter what. What brand of seal did you use? You can put a thin smear of grease on the flywheel sealing surface and then slide the flywheel into place to see where the new seal rides.

[?Waldo?]

Check the galley plugs.
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I am a high-functioning autistic into VW diesels and Vanagons along with other things that are unrelated to this site.

[cannonfodder4j]

I think the seal was an OEM im not sure though the guy who sold the van to me gave the seal as well.

[joemac]

Uh... if it's the seal behind the flywheel, and the flywheel faces the front of the vehicle, shouldn't it be referred to as the "front main seal"?

[tencentlife]

Please let's not get into THAT silly discussion again.

You can pop new seals in and out 'til they cart you off, but if your flywheel has a deep groove on the seal hub it will still leak, repositioning the seal at a different depth will not help, instead that will trash the new seal even quicker. If the groove is deep enough to catch your fingernail in, it is too far gone and you should find a new FW or replacement in better condition, but grooves shallower than that can be improved.

The FW can be set up in a lathe or other device to turn it steadily (I have done them by hand bolted to a crankshaft and that laid in V-blocks, but made an adapter for my lathe) and the groove abraded out and polished by using successively finer grades of abrasive paper or cloth (emery is preferred for steel), lubricate generously with WD40 or something light. Start with a 40-grit, work up to 1200 or 2000. Take your time and get it to as smooth a finish as possible. Extra points for doing a final polish with a cotton buff and suitable polishing compound.

Lube the new seal lip and the FW hub with medium oil or grease. Be sure to install a fresh o-ring, oiled, in the FW hub. Deburr the nose of the crank so the o-ring goes on smoothly, and smear oil on it. If you observe these procedures you can get a leak-free main seal, in my experience anything short of these steps means you will be doing the job over.
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[cannonfodder4j]

thanks for the info ill definitely have a look when i work on it on sunday. I'm just waiting for a replacement seal to arrive. I suddenly am unsure whether or not greased the seal. Would it have mad a big difference?

[?Waldo?]

[joemac]

Hey, I was simply making an observation.

Check that stupid cam plug for leakage. I say stupid because there was nothing wrong with the steel plug that was used for decades.

Another point: the farther out the seal is placed in the crankcase, the tighter it seals against the bell of the flywheel hub. Setting the seal farther into the case allows for leakage even if a perfectly good flywheel is used.

Yet another point: how much crankshaft end play is there? Too much will hammer the seal, and more importantly, the thrust bearing.

[EvilDNA]

Finally. I managed to post the Boston Bob video I dug up from an old backup. WMV, Picasa and Mac DO NOT PLAY WELL TOGETHER! After the conversion and upload, etc. the video is worse than the original but nonetheless . . .

http://picasaweb.google.com/vwvanagons/BostonBobFlywheelVideo#
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1990 4 Speed Orly Blue Multivan

[cannonfodder4j]

woah thanks so much that videos really incredible. thanks a lot!!!

[joemac]

There is so much wrong with that video, I don't know where to start.
You don't drive a needle pilot bearing in with a hammer. Nor do you drive a flywheel seal in with a hammer. Any knowledgeable technician owns and uses bushing/bearing installers. That's what they're designed for.

I guarantee that after that engine has developed oil pressure, the crankshaft end play will have diminished by .0015", due to the coating of oil that forms between the shims/thrust. Any time you measure and adjust something that deals with flowing lubricant, you must compensate by simulating the conditions of operation. When rebuilding transmissions, you simulate running conditions when adjusting the gear package by actually pouring gear oil over the gears while cranking the mainshaft, which SIMULATES RUNNING CONDITIONS. Likewise, you want the shims/ thrust coated with engine oil to SIMULATE RUNNING CONDITIONS.

And to me, it is NOT perfectly acceptable to call the front main seal by anything other than its correct name. Don't point to a bolt and call it a nut. Yeah, I may know what you mean, but if that's the only criteria, let's just go back to pointing and grunting.

[Wildthings]

[sanchius]

[?Waldo?]

[Wildthings]

[iltis74]

So is the guy in the jump seat looking out back through the windshield? I mean, the factory did orient him that way. Man this is funner than I thought. In the end of course you can call it whatever you want, don't bother me, I know what it is.