Is it possible to replace the timing cover on SBC w/o dropping the oil pan?

[RobOp]

I think I may have a misaligned timing chain cover on a 1989 4.3LX causing the harmonic balancer seal to repeatedly fail in a very short period of time.

I have ordered a tool to install the seal and hold the cover in place centered on the crankshaft. I would really like to remove the timing cover and re-install it (or a new one) using the alignment tool.

Is this possible without dropping the oil pan? I think dropping the oil pan means removing the engine from the boat.

 

[RogersJetboat454]

Re: Is it possible to replace the timing cover on SBC w/o dropping the oil pan?

Eh...
You can try, but chances are you will have another oil leak on your hands after...

 

[Bondo]

Re: Is it possible to replace the timing cover on SBC w/o dropping the oil pan?

Is this possible without dropping the oil pan? I think dropping the oil pan means removing the engine from the boat.

Ayuh,... It's possible to cheat the process, but the odds are against you stopping ALL the oil leaks that'll result.....

Pull the motor, 'n do it Right...

 

[RobOp]

Re: Is it possible to replace the timing cover on SBC w/o dropping the oil pan?

Let me re-phrase the question a little.

The engine is a new Mercruiser-Quicksilver reman with about a dozen hours of run time. Since it was installed it has chewed up the timing cover seal (harmonic balancer seal) three times.

This is part of an on-going troubleshooting effort to find out why this engine is consistently shreading the harmonic balancer seal, the seal is not just leaking, it is being chewed up in as little as 30 minutes of run time under load.

A new harmonic balancer has been installed with no change.

My thinking is the problem is either crankshaft vibration or timing chain cover misalignment.

With no load the engine does not appear to have excessive vibration, under load while cruising it is hard to evaluate. I can put a foot on both the port and starboard engines and the vibration seems about the same. There is no detectable slop in the crankshaft end.

My next step is to try and properly align the timing chain cover and see if it continues to shread new seals. I know the right way to do it is to pull the engine and remove the oil pan. I do not have the ability to pull the engine myself.

Right now I don't care about the right way, I can always pull the engine and do things right if I sort out this seal problem. Right now I just want to know if I can re-align the timing cover without pulling the engine.

 

[Bondo]

Re: Is it possible to replace the timing cover on SBC w/o dropping the oil pan?

Right now I don't care about the right way, I can always pull the engine and do things right if I sort out this seal problem. Right now I just want to know if I can re-align the timing cover without pulling the engine.

Yes,...



But you'll probably have leaks somewhere below the crankshaft seal, later...

 

[Jmunk]

Re: Is it possible to replace the timing cover on SBC w/o dropping the oil pan?

Although different motor and different space limitations - I changed out the timing cover on my 3.0L with the engine still in the boat. Remove old cover, cut old oil pan gasket flush with sides of block, lay bead of quality RTV on lip of oil pan, install timing cover and make sure the crank snout is center in the crank seal. I have done this on cars more time then I can count when doing cam changes. The cover on my 3.0L sealed up and doesn't leak a drop. If you do it this way be sure you have the room you need to work and get a quality RTV, I only use "THE RIGHT STUFF" it's in an aerosol can and is top notch. I know doing it in the boat is not best practice, but can be done and seal fine.

The professionals will recommend to pull the motor so they can install a new oil pan gasket and guarantee their work.

 

[RogersJetboat454]

Re: Is it possible to replace the timing cover on SBC w/o dropping the oil pan?

Although different motor and different space limitations - I changed out the timing cover on my 3.0L with the engine still in the boat. Remove old cover, cut old oil pan gasket flush with sides of block, lay bead of quality RTV on lip of oil pan, install timing cover and make sure the crank snout is center in the crank seal. I have done this on cars more time then I can count when doing cam changes. The cover on my 3.0L sealed up and doesn't leak a drop. If you do it this way be sure you have the room you need to work and get a quality RTV, I only use "THE RIGHT STUFF" it's in an aerosol can and is top notch. I know doing it in the boat is not best practice, but can be done and seal fine.

The professionals will recommend to pull the motor so they can install a new oil pan gasket and guarantee their work.

So you're relying on a 1/2 inch bead of RTV to make a seal with a 90? turn and bond to what is most likely an oil soaked rail gasket? Us professionals do it right because having to doing it again is a waste of time.

 

[90stingray]

Re: Is it possible to replace the timing cover on SBC w/o dropping the oil pan?

In either of my boats there appears to be enough room to fully drop the pan. I do need to change the timing chain on my Stingray... but have yet to accomplish this. You could try to lower the pan all the way down to change the entire pan gasket, pending your clearance in your boat. But since this is just for troubleshooting... the shortcut method will probably do.

 

[John_S]

Re: Is it possible to replace the timing cover on SBC w/o dropping the oil pan?

A SBC 4.3L???

If Merc remans, they should be dealing with this issue on warrantee vs you.

Not familiar with doing a 4.3L timing cover, but no alignment (outside of pins) on SBC. Shreading the balancer seal, is significantly different from having an oil drip. Is this the plastic timing cover? or have you just replaced the seal in the metal cover? If the latter, maybe time for a new cover(mfg defect?). I remember AChris mentioning repeated cracking of a timing cover on one of his 4.3Ls. If it is plastic, it is suppose to get replaced everytime, and not reused.

You replaced the balancer, which would have been my 1st guess. Was there any rust on the surface near where it seals? Have you pulled the new one to see what it looks like? Thinking of the possibility of a small water pump or other leak dripping on inner part of balancer and causing rust.

I did my 5.7L in the boat (cam change), and it did take a second time to get it sealed. I was able to loosen, drop front of the oil pan within the boat, though.

 

[Jmunk]

Re: Is it possible to replace the timing cover on SBC w/o dropping the oil pan?

double post

 

[Jmunk]

Re: Is it possible to replace the timing cover on SBC w/o dropping the oil pan?

So you're relying on a 1/2 inch bead of RTV to make a seal with a 90? turn and bond to what is most likely an oil soaked rail gasket? Us professionals do it right because having to doing it again is a waste of time.

As mentioned above you cut the old oil pant gasket flush at both ends of the block and toss it, then clean the rail well and lay RTV. I am not a professional, but have done this on a number of cars with no leaks, and worked on my 3.0L. Maybe I just get lucky when I do it ? It's advice, if you think you can use it then take it, if not disregard and move on with life.

 

[joewithaboat]

Re: Is it possible to replace the timing cover on SBC w/o dropping the oil pan?

Although different motor and different space limitations - I changed out the timing cover on my 3.0L with the engine still in the boat. Remove old cover, cut old oil pan gasket flush with sides of block, lay bead of quality RTV on lip of oil pan, install timing cover and make sure the crank snout is center in the crank seal. I have done this on cars more time then I can count when doing cam changes. The cover on my 3.0L sealed up and doesn't leak a drop. If you do it this way be sure you have the room you need to work and get a quality RTV, I only use "THE RIGHT STUFF" it's in an aerosol can and is top notch. I know doing it in the boat is not best practice, but can be done and seal fine.

The professionals will recommend to pull the motor so they can install a new oil pan gasket and guarantee their work.

I to have done this numerous times with no leaks at all.

So you're relying on a 1/2 inch bead of RTV to make a seal with a 90? turn and bond to what is most likely an oil soaked rail gasket? Us professionals do it right because having to doing it again is a waste of time.

You remove all old gaskets and clean well, no oil soaked anything. Charging to pull an engine to change a timing cover gasket is loony.

I think as John S is recalling with achris, This might be more than a seal problem. These are achris's threads on the matter maybe o/p is having similar problem.

http://forums.iboats.com/showthread.php?t=373060

http://forums.iboats.com/showthread.php?t=512928

http://forums.iboats.com/showthread.php?t=518188

 

[RogersJetboat454]

Re: Is it possible to replace the timing cover on SBC w/o dropping the oil pan?

A SBC 4.3L???

Don't laugh... they made those too. A nice 110hp V8 weakling in the mid 70's.

 

[Alwhite00]

Re: Is it possible to replace the timing cover on SBC w/o dropping the oil pan?

You can replace the gasket W/O removing the oil pan - the corners of the lip on the timing cover need to pe trimmed off on a 45 deg angle so it will "tip" into position. (See pic) Put a dab of silicone in the corners and you will not have a problem. You can get in there and clean the oil off with a rag after the cover is off as it created enough room to get in there with the cover off.

LK

 

[RogersJetboat454]

Re: Is it possible to replace the timing cover on SBC w/o dropping the oil pan?

You fellas can fix your engines in any way you like. The whole purpose of these forums to to provide people with answers to questions, and not all answers are the best or rational.

Whether the OP chooses seal his timing cover to the oil pan the right way or your way is his decision. You guys are basically telling him to use RTV in a way it was never intended to be used (forming a 1/2 inch gasket on a thin oil pan lip), and no manufacture or reputable dealer who has to do warranty repair work would even consider this procedure acceptable (consider the fact that this engine may still be under warranty).

Having to lift the engine partially out of the bilge to gain access to the pan is not the end of the world, and is not a several day affair. We are talking a matter of a few hours here to do it right, and have the piece of mind that when it's all done the engine won't leak, or even worse blow a make-shift seal out and allow the contents of the pan to start pouring into the bilge.

 

[RobOp]

Re: Is it possible to replace the timing cover on SBC w/o dropping the oil pan?

Its the metal cover.

I was told the GM-V6 engine is a SBC, same as the V8 with two cylinders cut off. But I'm no expert....

I bought the boat this last November (2011), The previous owner had the engine changed in September 2010, so no warranty.

He only put a handful of hours on the new motor and never noticed the oil leak. (He also thought the 4.3 LX was a V8 not a V6, not a motorhead!)

The original harmonic balancer looked fine, no rust. There was a small groove from the original engine but not that bad. Considering the fact that I suspect vibration it seemed like a cheap thing to try ($53 from NAPA).

I will try a new timing cover without pulling the pan.

I thank everyone for all the advise! I'll post another update when I know more.

 

[joewithaboat]

Re: Is it possible to replace the timing cover on SBC w/o dropping the oil pan?

You fellas can fix your engines in any way you like. The whole purpose of these forums to to provide people with answers to questions, and not all answers are the best or rational.

Whether the OP chooses seal his timing cover to the oil pan the right way or your way is his decision. You guys are basically telling him to use RTV in a way it was never intended to be used (forming a 1/2 inch gasket on a thin oil pan lip), and no manufacture or reputable dealer who has to do warranty repair work would even consider this procedure acceptable (consider the fact that this engine may still be under warranty).

Having to lift the engine partially out of the bilge to gain access to the pan is not the end of the world, and is not a several day affair. We are talking a matter of a few hours here to do it right, and have the piece of mind that when it's all done the engine won't leak, or even worse blow a make-shift seal out and allow the contents of the pan to start pouring into the bilge.

Roger,
No one is suggesting the o/p do anything unsafe or that would void his warranty if he has one.

Do you think general motors paid to pull engines for camshaft replacement under warranty ?.....

This trick has been used on small block chevys for years... The 4.3 is the same as far as this goes.
All of the gasket companies sold kits that contained the front portion of the oil pan gaskets, when they were cork,and instructions like above on how to trim the metal tabs so that cam changes could be done without lowering the pan. Some cars had cross-members so close you couldn't even get at the bolts to loosen them much less drop them.

In my boat i would be able to loosen the pan and lower it to prevent having to trim the tabs. If you think most folks pull the engine (car or boat) to change a front cover gasket i have some bad news for you, your mistaken. Sorry

P.S. once i got wise, i bought two piece covers that all but eliminate the hassle.

 

[RogersJetboat454]

Re: Is it possible to replace the timing cover on SBC w/o dropping the oil pan?

This trick has been used on small block chevys for years... The 4.3 is the same as far as this goes.
All of the gasket companies sold kits that contained the front portion of the oil pan gaskets, when they were cork,and instructions like above on how to trim the metal tabs so that cam changes could be done without lowering the pan.

Yep.. Well aware of this. None of those companies would tell you to substitute the included lip seal with RTV either.Those end seals seal marginally at best when installed correctly. Why do you suppose GM went to 1 piece pan gaskets?

If you think most folks pull the engine (car or boat) to change a front cover gasket i have some bad news for you, your mistaken. Sorry

You and those folks are welcome to do what you want. You're not going to convince me to change the way I re-seal an engine. Sorry I KNOW my engines and the engines I service won't leak when I'm done with them.

P.S. once i got wise, i bought two piece covers that all but eliminate the hassle.

That I will agree with you on. A 2 piece timing cover is a beautiful thing...

 

[Jmunk]

Re: Is it possible to replace the timing cover on SBC w/o dropping the oil pan?

You fellas can fix your engines in any way you like. The whole purpose of these forums to to provide people with answers to questions, and not all answers are the best or rational.

Whether the OP chooses seal his timing cover to the oil pan the right way or your way is his decision. You guys are basically telling him to use RTV in a way it was never intended to be used (forming a 1/2 inch gasket on a thin oil pan lip), and no manufacture or reputable dealer who has to do warranty repair work would even consider this procedure acceptable (consider the fact that this engine may still be under warranty).

Having to lift the engine partially out of the bilge to gain access to the pan is not the end of the world, and is not a several day affair. We are talking a matter of a few hours here to do it right, and have the piece of mind that when it's all done the engine won't leak, or even worse blow a make-shift seal out and allow the contents of the pan to start pouring into the bilge.

1/2" thick oil pan gasket ? Never seen one of those. I'd prob lay a 1/4" bead and let it setup for 10 min then put the cover on. Either way the original poster has been given numerous to fix the issue. Which way he chooses is up to him.

 

[Don S]

Re: Is it possible to replace the timing cover on SBC w/o dropping the oil pan?

Yeah, if I couldn't do the job right, that is exactly how I would do it. Then pray it didn't leak, and cuss like a banshee because it did leak knowing full well it was a short cut at best. Why would GM put that extra tab in there to be cut off by lazy mechanics, if it wasn't needed to prevent leaks? Automotive engines might get away with it because it leaks on the ground, boat engines leak in the bilge, and the local officials get upset if your bilge pump pumps oil into the water.