Rear Oil Seal

[mike.smith]

I'm going to put in the new rear oil seal today. I went back to my Kitlog to see what I did the first time. I see that I had a question about what point the seal gets set to (item #3).

http://www.mykitlog.com/users/display_l ... 03&row=131

And this later post was related. Maybe those oil return holes are supposed to be covered by the gasket?

http://www.mykitlog.com/users/display_l ... 95&row=126

Knowledge or thoughts are appreciated.

[SonexN76ET]

Mike,

I installed my oil seal flush with the back of the case as you show in your original build photos. I don't think you can install it any deeper without disfiguring the seal. I also ensured my oil return holes were open. These holes allow any oil that makes it past the bearing to drip back into the case versus blowing out the rear seal.

You didn't have any leaks from the rear seal in the original installation did you?

Do you have the red book "Rebuilding Your Air Cooled VW"?

Perhaps others can chime in here as well?

I hope you are able to get back in the air soon! I have added checking the trigger shaft for looseness each time I take off the cowling to my maintenance checklist.

Thanks,

Jake

[mike.smith]

Mike,

I installed my oil seal flush with the back of the case as you show in your original build photos. I don't think you can install it any deeper without disfiguring the seal. I also ensured my oil return holes were open. These holes allow any oil that makes it past the bearing to drip back into the case versus blowing out the rear seal.

You didn't have any leaks from the rear seal in the original installation did you?

I always had a little oil coming from the area of the back of the case, but I could never pin down the source for sure. Since I replaced the entire flywheel assembly it made sense to replace the seal.

Do you have the red book "Rebuilding Your Air Cooled VW"?

I do, but not every little detail is noted. This was one of them.

Perhaps others can chime in here as well?

I hope you are able to get back in the air soon! I have added checking the trigger shaft for looseness each time I take off the cowling to my maintenance checklist.

Thanks,

Jake

Dudley Foster provided me with the best explanation: "The lip of the seal rides on the flywheel, so that flywheel inner flange is the sealing surface. If the seal is in too far, it might not ride on the flywheel flange. There is probably a polished wear mark on the flywheel flange where the old seal was riding. It shouldn't be too close to the edge."

It only took me a few hours to put it all back together. Tonight I'll re-hang the engine and connect everything back up. After I do the compression check to finish my annual I should be able to run the engine tomorrow.

[MichaelFarley56]

Hey Mike,

It sounds like Jake and Dudley have it all figured out for you.

The only two things I would add is that, before you install the flywheel seal, make sure its internal spring doesn't have any kinks. I made that mistake and when i first started my engine, oil poured out of that seal. I probably messed it up when I installed it but certainly worth checking.

Second, a coat of white lithium grease on the flywheel flange where the seal rides will help from messing up the seal during the first start until oil pessure is built up. And you're correct in that those oil passages need to be clear to allow oil to drain back into the case.

Good luck on getting the airplane back in the air!