Replacing Flywheel Seal

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whc03grady
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Replacing Flywheel Seal

Post by whc03grady » Tue Sep 29, 2015 9:28 am

I called up my localish VW parts guy the other day to get some stuff in anticipation of putting my engine and transaxle back in. He said I should do the flywheel seal and o-ring while I'm there. Does the flywheel have to come off to determine if a leak even exists? Then, is there a write-up on replacing the seal and o-ring or is Bentley good enough.
Ludwig--1974 Westfalia, 2.0L (GD035193), Solex 34PDSIT-2/3 carburetors.
Gertie--1971 Squareback, 1600cc with Bosch D-Jetronic fuel injection from a '72 (E brain).
Read about their adventures:
http://www.ludwigandgertie.blogspot.com

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BellePlaine
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Re: Replacing Flywheel Seal

Post by BellePlaine » Wed Sep 30, 2015 11:05 am

Did your engine drip oil from the flywheel area? If so, then the answer is obvious. If not, then I suspect you'd have to remove the flywheel to detect any seepage. Have your spare flywheel shims and dial indicator handy in case you should need to adjust endplay. I believe Colin used Indian Head Shellac Gasket Sealer to seal the flywheel seal.

Image
Here's a pic of my flywheel seal. It looked pretty good so I didn't bother replacing it. This photo is to show my peening work around the galley plugs. I used a pointed punch and hammer to make the peens.

Woah... now that I'm taking a closer look at the above photo, make sure your shims are not as nasty as mine are here. I assure you that I removed these shims using a magnet and they were clean before I installed the flywheel. Yikes!

And since you asked, you may as well consider replacing the needle bearing (set in the flywheel end of the crankshaft), or at least put an pinky finger schmeer of lubricant on the bearing. If you replace it, you'll need a needle bearing puller and a slide hammer. They can be rented at your FLAPS. Also, consider replacing the transmission input shaft seal, especially if there is a lot of oil in the bell housing. You'll likely need a gasket puller to remove the old seal.

Old Seal
Image

New Seal
Image

Comparison
ImageImage
1975 Riviera we call "Spider-Man"

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whc03grady
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Re: Replacing Flywheel Seal

Post by whc03grady » Thu Oct 01, 2015 12:14 pm

BellePlaine wrote:Did your engine drip oil from the flywheel area? If so, then the answer is obvious. If not, then I suspect you'd have to remove the flywheel to detect any seepage. Have your spare flywheel shims and dial indicator handy in case you should need to adjust endplay. I believe Colin used Indian Head Shellac Gasket Sealer to seal the flywheel seal.
Without going into detail about my comically precarious living/working situation, I can't afford to do anything this time around I don't need to do, especially if there's any chance of screwing it up. Maybe my more specific question is, is it a bad idea to remove the flywheel from a balanced engine if one suspects a seal leak?
BellePlaine wrote:And since you asked, you may as well consider replacing the needle bearing (set in the flywheel end of the crankshaft), or at least put an pinky finger schmeer of lubricant on the bearing. If you replace it, you'll need a needle bearing puller and a slide hammer. They can be rented at your FLAPS. Also, consider replacing the transmission input shaft seal, especially if there is a lot of oil in the bell housing. You'll likely need a gasket puller to remove the old seal.
See above. Unless absosmurfly necessary I'm not doing anything requiring renting tools with 'puller' in their names. I will put some lubricant (what kind, exactly?) on the needle bearing but truth be told this engine is pretty fresh--it's not to blame for its own removal--and I'd find it hard to believe something like that had gone South already (though I've certainly had my ass handed to me on that account before). The transaxle is less fresh and is the cause of the removal, albeit an entirely different component. However, the bell housing wasn't especially oily inside; I'll do a visual inspection of the input shaft seal anyway just in case.
Ludwig--1974 Westfalia, 2.0L (GD035193), Solex 34PDSIT-2/3 carburetors.
Gertie--1971 Squareback, 1600cc with Bosch D-Jetronic fuel injection from a '72 (E brain).
Read about their adventures:
http://www.ludwigandgertie.blogspot.com

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asiab3
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Re: Replacing Flywheel Seal

Post by asiab3 » Thu Oct 01, 2015 1:41 pm

I've never personally replaced a seal that wasn't leaking. Then again, my experience is limited to my own engine and that is it. I think from a shop's point of view, it would be prudent to replace a seal of unknown age, because a customer would bring it back if a leak started soon after the shop did work on it.

The pilot bearing, (in the gland nut on T1, and in the crank on T4,) should be lightly lightly greased with whatever is in there already. If you don't know, I don't know how to recommend it and be 100% confident. I've used good red wheel bearing grease before. I used black Valvoline Moly grease on the current engine. If you have a felt wick in front of the bearing, hit that with a few drops of oil. This keeps any clutch dust off of the pilot bearing to help extend its life.

IF you pull the flywheel off, oil will run out of the seal area. So if you're inspecting for leaks, try to do as much as you can before removing the flywheel. If the flywheel is removed, oil the lip of the seal and the sealing surface of the flywheel to prevent ripping the seal on first start; this is especially important on a new seal. Does a T4 flywheel use a similar graphite o-ring like the T1 inside the flywheel where it mates to the crank? If so, I like a new one of these every time I remove the flywheel.

As long as the flywheel (and pressure plate!) goes back on in the same orientation it came off, the engine balance will not be affected.

Mitch, is your desire to keep the job low-key a financial or physical one? There are some "free" jobs that I do every so often when the engine is out, like lubricating the clutch fork rotating points with grease, and greasing the throw out bearing saddles on the clutch fork. I also like to make sure the 10mm clutch arm grub screw is secure, and the throw out bearing is not gritty. You should also apply an extremely light coating of grease to the input shaft splines before reinstall, as the clutch has to slide back and forth on it for proper operation. If you have the pressure plate off, install the clutch several different ways to make sure there are no hangups. Bentley says to use graphite powder, which would work well, but I think it's more important to be consistent with what is on the shaft already. I don't like to mix lubricant types. Conservative application of clean grease is key here, we don't want to contaminate the clutch.

I often venture down rabit holes of maintenance. I installed a new transaxle this year, and it took six hours. Five of those hours were things like touching up paint, inspecting wiring, and other nonsense. It can be done quick, but taking a bit of extra time is FUN. REAL FUN, DANGIT. I promise.

Robbie
1969 bus, "Buddy."
145k miles with me.
322k miles on Earth.

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SlowLane
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Re: Replacing Flywheel Seal

Post by SlowLane » Thu Oct 01, 2015 4:38 pm

Mitch, if you do decide to go ahead and replace the seal, give this article by GoWesty a read. Seems GoWesty has the inside track on The Only Seal Worth Having, as All Other Seals Are Cr*p.

Seriously, though, the article makes sense, and if you're going to the trouble, you might as well have the best seal available.

Assuming we are talking about your bus, that is, and not the squareback.
'81 Canadian Westfalia (2.0L, manual), now Californiated

"They say a little knowledge is a dangerous thing, but it is not one half so bad as a lot of ignorance."
- Terry Pratchett

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Amskeptic
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Re: Replacing Flywheel Seal

Post by Amskeptic » Tue Oct 06, 2015 9:04 pm

asiab3 wrote:If you have a felt wick in front of the bearing, hit that with a few drops of oil.
This keeps any clutch dust off of the pilot bearing to help extend its life.

felt keeps bearing grease away from friction surfaces and clutch lining

IF you pull the flywheel off, oil will run out of the seal area.

Not on Type 4, it has a serious drain due south.

oil seal surface of the flywheel;
T4 o-ring inside the flywheel new one every time.

Yes.

As long as the flywheel (and pressure plate!) goes back on in the same orientation it came off, the engine balance will not be affected.

Type 4 flywheel is indexed with roll pin.
ColinEdit
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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asiab3
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Re: Replacing Flywheel Seal

Post by asiab3 » Tue Oct 06, 2015 11:35 pm

Amskeptic wrote: ColinEdit
Thanks for the corrections. Most of my wooly descriptions come from writing on TheSamba where six hundred people might view a short thread, so things like "make sure the flywheel is indexed" slip in to T4 threads from time to time. :blackeye:
1969 bus, "Buddy."
145k miles with me.
322k miles on Earth.

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Amskeptic
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Re: Replacing Flywheel Seal

Post by Amskeptic » Fri Oct 09, 2015 6:50 pm

asiab3 wrote:
Amskeptic wrote: ColinEdit
Thanks for the corrections. Most of my wooly descriptions come from writing on TheSamba where six hundred people might view a short thread, so things like "make sure the flywheel is indexed" slip in to T4 threads from time to time. :blackeye:
The scrum of sixty years of improvements across several model lines multiplied by hundreds of thousands of helpful posts is a recipe for the occasional correction.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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