Front main - why?

[varg]

That's one I've never seen before, the spring from a front main seal came off and got pinched between the sprocket and crank during hub installation?

[JerEazy]

That's one I've never seen before, the spring from a front main seal came off and got pinched between the sprocket and crank during hub installation?

I dont think the gear sits flush against the seal otherwise it would just tear the seal as soon as it spun turned over? Not sure. And there wasn’t a leak at installation and after test drive (did a smoke test after installation to be sure).

Only theory I have is that the seal blew out, and the spring got caught and twisted around. It was wrapped around the crank, I had to unwrap it to get it off. There was a chunk of the seal in the bottom of the housing.

[digger]

I dont think the gear sits flush against the seal otherwise it would just tear the seal as soon as it spun turned over? Not sure. And there wasn’t a leak at installation and after test drive (did a smoke test after installation to be sure).

Only theory I have is that the seal blew out, and the spring got caught and twisted around. It was wrapped around the crank, I had to unwrap it to get it off. There was a chunk of the seal in the bottom of the housing.

the seal fits about half way back on the journal as shown by the witness mark. As Varg stated the only way it indented there was if it was there before the crank gear was installed (maybe from the old seal) and the tightening of the bolt is the only way to generate enough force to imprint

[JerEazy]

the seal fits about half way back on the journal as shown by the witness mark. As Varg stated the only way it indented there was if it was there before the crank gear was installed (maybe from the old seal) and the tightening of the bolt is the only way to generate enough force to imprint

before I reinstall I am going to post up a picture of the seals installed so i can get thumbs up from the pros on its setting. Currently awaiting delivery.

[digger]

buy a good brand seal, makes sure it wont sit on the exact same groove in the crank by installing it slightly deeper or shallower into the timing cover but it must sit "square" in the cover, grease it and be careful you dont bend/fold the lip over on install other wise it will get a fine crack and leak in a short time. Perhaps heating it slightly with heat gun may make it more compliant/softer but i have never done this.

It would have been nice if the designers of the shafts had a proper lead in chamfer that complied with the manufacturers requirements. There are special tools around to help with lead in e.g. the rear main comes with one

[82eye]

. There are special tools around to help with lead in e.g. the rear main comes with one

damn. how expensive are they? i ruined one on install. second one went in no issues and has been good.

trying figure out how the front seal went so awful in this thread. guessing it's just harder to work on in the car.

[digger]

damn. how expensive are they? i ruined one on install. second one went in no issues and has been good.

trying figure out how the front seal went so awful in this thread. guessing it's just harder to work on in the car.

i haven't seen one for the m20 sizes to know, i am just going to turn my own from nylon round stock next time similar to what you get with the (genuine) rear main seal.

i once accidently folded over a cam seal as the aftermarket cam didn't have a nice lead in chamfer and unbeknown to me it cracked. needless to say there was a massive oil leak and the next day it was coming apart again and a big chunk had torn away......

[JerEazy]

Ok. So I’m thinking my issue was I left the front seal for the crank and oil pump more or less flush with the cover. I made a point to seat them a bit deeper. The backs of the seals are basically flush with the back of the cover.

If they were flush then the balancer gear and oil pump gear could have grabbed them and caused this failure. Here is how they are seated now. Before installing can I get a thumbs up from the brain trust? Could take more pictures if it'll help. Did not install yet.

[digger]

its probably the photo/light reflection (as they normal have a texture to them) but the edge of the lighter seal look uneven/non uniform. Yes you do need to make sure it is as a minimum perfectly flush as there at most 0.040" from the back of the gear to the front edge of the housing but going slightly deeper will sit on fresh metal so preferred on a well used engine

[JerEazy]

Ok - they are deeper - the back of them is flush with the back of the housing. I could push them back the other way a bit. And yes, that’s a lighting/angle issue on the oil pump seal. It is uniform and not torn or beat.