Mercruiser 5.0 crankshaft front oil seal replacement

[mdaddy]

2008 Mercruiser 5.0 tks Alpha One
serial#1A322719

Before I pull the harmonic balancer, is replacing the front oil seal pretty straightforward or are there any special issues to look out for? It's slinging oil from around the balancer/pulley, especially under load. Thanks.

 

[Bt Doctur]

just the room to remove the seal and drive the new one in

 

[alldodge]

Nothing special, remove and replace
My question would be what caused it to start leaking, for it to leak is rare. Wonder if its a cracked cover, but hey can be seen once balancer is removed

 

[Scott Danforth]

If your cover needs to be replaced, the motor needs to come out

 

[dubs283]

If your cover needs to be replaced, the motor needs to come out

Most boats I've seen don't have near enough room in front of the engine to get a proper tool to successfully pull/install the seal. Being most likely a plastic timing cover I would be suspect of damaging the cover.

Seeing as how it's highly recommended to replace it when it's removed I would opt to replace the entire cover and oil pan gasket.

 

[Scott Danforth]

Most boats I've seen don't have near enough room in front of the engine to get a proper tool to successfully pull/install the seal. Being most likely a plastic timing cover I would be suspect of damaging the cover.

Seeing as how it's highly recommended to replace it when it's removed I would opt to replace the entire cover and oil pan gasket.

I would also ditch the plastic cover for the billet aluminum front cover.

 

[tank1949]

2008 Mercruiser 5.0 tks Alpha One
serial#1A322719

Before I pull the harmonic balancer, is replacing the front oil seal pretty straightforward or are there any special issues to look out for? It's slinging oil from around the balancer/pulley, especially under load. Thanks.

Examine bearing surface carefully. Usually grit causes seal to fail. You may have to add a "Speedy seal" kit.

 

[mdaddy]

Nothing special, remove and replace
My question would be what caused it to start leaking, for it to leak is rare. Wonder if its a cracked cover, but hey can be seen once balancer is removed

It was a cracked timing chain cover- would dump several qts. of oil in 10-15 min. with severe oil pressure drop and I was baffled as the seal seemed improbable.... 12" crack along face of timing chain cover... ughhh! Replaced cover, sealed up, taking for a test run 2morrow am! Thanks!

 

[Scott Danforth]

Did you stick with plastic or go to an aluminum cover?

 

[tank1949]

I have never seen aluminum or plastic on a SB chevy motor. Was it cracked or eroded? If you have too loose chain, you should examine carefully.

 

[Scott06]

I have never seen aluminum or plastic on a SB chevy motor. Was it cracked or eroded? If you have too loose chain, you should examine carefully.

Mid 90’s and up vortec engines came with plastic covers from GM.

 

[Scott Danforth]

I have never seen aluminum or plastic on a SB chevy motor. Was it cracked or eroded? If you have too loose chain, you should examine carefully.

1996 and later motors went plastic. Aftermarket solution is aluminum

 

[tank1949]

1996 and later motors went plastic. Aftermarket solution is aluminum

Plastic???? No wonder it crapped out!

 

[Scott Danforth]

Plastic???? No wonder it crapped out!

Yes, auto makers now make plastic intakes, plastic oil pans, valve covers, timing covers. For a vehicle that lasts 4-8 years it's not a problem. However in a boat that lasts 15+, it's a real issue

One of the many reasons I prefer to refurb/rebuild vs buy new

Luckily the aftermarket SBC aluminum bits are cheaper than the plastic OEM bits

 

[Scott06]

Its not like tin valve and timing covers never leaked…

 

[Jmunk]

The lip inside the timing cover where it seals upto the oil pan makes it nearly impossible to replace the cover without dropping the oil pan.

Like most things, I’m sure going to plastic saved GM a few dollars per engine.

 

[Lou C]

While the old style tin parts can rust through I think they’re better than plastic!
Just spray the timing chain cover & oil pan once a year with Corrosion X. Worked for me 20+ years in salt water!

 

[tank1949]

The lip inside the timing cover where it seals upto the oil pan makes it nearly impossible to replace the cover without dropping the oil pan.

Like most things, I’m sure going to plastic saved GM a few dollars per engine.

UR correct on SB Chevy V8s. I have replaced several in my 73 years. Pain in the butt!