ferox Posted October 1, 2011 Share Posted October 1, 2011 I pulled my engine to replace the rear main seal that was leaking and found that the existing seal was pushed/pulled in way too far. It is my understanding that the seal should be flush with the bellhousing and that having it in so far may restrict oil flow. The pics are somewhat bad. The only digicam that I currently have that will actually take a picture has to be coaxed to do so. First I would like to verify that this is not the way it is supposed to be.(?) Second, is there some condition that would cause this like vacuum pulling it in, or somehow getting pushed in (though it don't see how that could happen)? Thirdly, is there a particular part or area of the engine that would be oil starved due to this condition? I have been trying to diagnose a front end noise similar to a bad CV that occurs under load (CVs have been replaced with no change in noise). I checked for thrust bearing wear and crank walk with a good amount of leverage, so I don't think that is an issue, but does rod knock in an H4 sound anything like a bad CV? Quote Link to comment Share on other sites More sharing options...
Crazyeights Posted October 1, 2011 Share Posted October 1, 2011 Yes, it is pushed in too far. Also use lock-tite on the flywheel bolts as oil can leak past the threads on those as well. Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted October 1, 2011 Share Posted October 1, 2011 No it should not be like that. Crankcase's build pressure and tend to blow out seals not suck them in. Likely it was simply installed that way. Nothing will be starved of oil - if the seal is installed at full depth like that it will partially block the return hole at the bottom of the seal pocket. This can cause the seal to have too much oil surrounding the lip and thus it can leak past. I would have to hear the sound to determine if it's likely to be a rod knock or not. GD 1 Quote Link to comment Share on other sites More sharing options...
ferox Posted October 1, 2011 Author Share Posted October 1, 2011 Yes, it is pushed in too far. Also use lock-tite on the flywheel bolts as oil can leak past the threads on those as well. Thanks for the response. It's hard to see, but I did actually use loctite. Quote Link to comment Share on other sites More sharing options...
ferox Posted October 1, 2011 Author Share Posted October 1, 2011 Nothing will be starved of oil - if the seal is installed at full depth like that it will partially block the return hole at the bottom of the seal pocket. This can cause the seal to have too much oil surrounding the lip and thus it can leak past. That's a relief. I would have to hear the sound to determine if it's likely to be a rod knock or not. Yeah I have considered bringing it by your place. I try to exhaust all of my diagnostic abilities before I ask for help, but if I can't figure it out once I get the car put back together I'll give you a call. Thanks for the quick response. Quote Link to comment Share on other sites More sharing options...
ruparts Posted October 2, 2011 Share Posted October 2, 2011 (edited) I pulled my engine to replace the rear main seal that was leaking and found that the existing seal was pushed/pulled in way too far. It is my understanding that the seal should be flush with the bellhousing and that having it in so far may restrict oil flow. The pics are somewhat bad. The only digicam that I currently have that will actually take a picture has to be coaxed to do so. First I would like to verify that this is not the way it is supposed to be.(?) Second, is there some condition that would cause this like vacuum pulling it in, or somehow getting pushed in (though it don't see how that could happen)? Thirdly, is there a particular part or area of the engine that would be oil starved due to this condition? I have been trying to diagnose a front end noise similar to a bad CV that occurs under load (CVs have been replaced with no change in noise). I checked for thrust bearing wear and crank walk with a good amount of leverage, so I don't think that is an issue, but does rod knock in an H4 sound anything like a bad CV? ((( THAT SEAL LOOKS LIKE IT IS INSTALLED BACKWARDS !!! ))) IF IT IS , NO SURPRISE IT LEAKS the hollow side goes in toward the front of the engine. Edited October 2, 2011 by ruparts Quote Link to comment Share on other sites More sharing options...
ferox Posted October 2, 2011 Author Share Posted October 2, 2011 ((( THAT SEAL LOOKS LIKE IT IS INSTALLED BACKWARDS !!! ))) IF IT IS , NO SURPRISE IT LEAKS the hollow side goes in toward the front of the engine. It was installed with the correct side in. The engine has 286k on it and the rear main just started leaking. I have personally put the last 66k on it and changed the clutch once in that time. I don't remember what the rear main looked like during the clutch replacement, but I do remember that the bellhousing was remarkably clean behind the flywheel. When I removed it I found that the seal was barely even on the crank. It popped inside as soon as I touched it with my picks. I don't have an explanation as to why it is was like this, but at this point I don't think it was installed that way or it would have failed a long time ago. Somehow, maybe through wear and heating and cooling it worked it's way in. I did recently drive to Bellingham and back (9 hours) at full speed (other than Seattle) in hot weather. I can't get my crank to move forward or backward at all so I don't think the crank is walking back and forth. New seal is installed, so if it does it again then obviously there is a bigger problem that likely involves engine replacement. For now I call it a fluke. Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted October 2, 2011 Share Posted October 2, 2011 Often old rubber will shrink - it probably wasn't a real tight fit anymore and just slowely worked it's way in till the lip popped off the back of the crank. GD Quote Link to comment Share on other sites More sharing options...
ferox Posted October 3, 2011 Author Share Posted October 3, 2011 Often old rubber will shrink - it probably wasn't a real tight fit anymore and just slowely worked it's way in till the lip popped off the back of the crank. GD Yeah I was thinking something like that must be the case. The rubber material was really brittle and who knows how long ago it was replaced. I could probably go through the three-inch thick file I have on the car and find the date/odo of replacement but I'd rather get other things done. The engine is back in the car... we'll see how it goes. Quote Link to comment Share on other sites More sharing options...
Soobie-ruu Posted October 3, 2011 Share Posted October 3, 2011 I know this may be off topic, if you don't use locktite on the flywheel bolts wat else can be caused by them backing out of the holes Quote Link to comment Share on other sites More sharing options...
lrgvanman Posted November 7, 2021 Share Posted November 7, 2021 Funny how this very same thing happened to the front crank seal of mine. Quote Link to comment Share on other sites More sharing options...
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