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

[Alwhite00]

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

You still use all of the gaskets as intended you are just trimming the tab to allow it to be assembled wo dropping the pan. Nobody said anything about 1/2
Inch of silicone, i use a dab in the corners even with the pan pulled. Done this numerous times with no issues.

LK

 

[joewithaboat]

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

You still use all of the gaskets as intended you are just trimming the tab to allow it to be assembled wo dropping the pan. Nobody said anything about 1/2
Inch of silicone, i use a dab in the corners even with the pan pulled. Done this numerous times with no issues.
LK

^^^ exactly!!!

I cant believe you guys, pulling an engine to change a front cover ????????????? Loony toons

 

[alame]

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

I find this forum to be an excellant source of information on so many boating topics........but seperating the chaff from the wheat can sometimes be difficult !! and I say this from my recent posting on another thread on this forum ...........

 

[ENSIGN]

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

Before you put things back together at least put a dial indicator on the front of the crankshaft to make sure it's straight !! Make sure you have a harmonic balancer install tool. (it's not a big hammer)

 

[sschefer]

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

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.

Sometimes the vibration damper will get a depression worn into it where the seal meets the shaft portion. That may be your problem and it's hard to actually see it but if you lay a straight edge on it you can. I have mine turned and sleeved. As for getting the cover to seal at the corners of the pan, you've already been told it's rarely achieveable. I've had some successes on 5.7L motors using just a dab of silicone on each end of the seal. I found it to be a case of less is more.

 

[joewithaboat]

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

Sometimes the vibration damper will get a depression worn into it where the seal meets the shaft portion. That may be your problem and it's hard to actually see it but if you lay a straight edge on it you can. I have mine turned and sleeved. As for getting the cover to seal at the corners of the pan, you've already been told it's rarely achieveable. I've had some successes on 5.7L motors using just a dab of silicone on each end of the seal. I found it to be a case of less is more.

Putting a new seal surface on the harmonic balancer is a great idea! I have never heard of one that needs the old balancer to be turned, but not doubting that it might exist. Felpro makes one that needs no turning and is available at any parts store. I have used them more times than i can count.

http://www.summitracing.com/search/...armonic-Balancer-Repair-Sleeves/?autoview=SKU

I also have changed more front covers on small block Chevys than i could count, doing cam changes in the car. It is always helpful if you can lower the pan a little. I have done it many times without lowering with no oil leaks. Don't be fooled into thinking that you are doomed to have oil leaks unless you pull your engine. Millions of them have been done that way.

On things I have worked on most oil leaks on a cork gasketed pan could be traced to the pan bolts being overtight, dimpling the pan. Same goes for the front cover. A little #2 permatex seems to help around the crank seal on the front cover before installing it. I think it also works better than silicone on the paper gasket on the cover but have used either with success.

Good luck, happy wrenching!

 

[dollarten]

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

Putting a new seal surface on the harmonic balancer is a great idea! I have never heard of one that needs the old balancer to be turned, but not doubting that it might exist. Felpro makes one that needs no turning and is available at any parts store. I have used them more times than i can count.

http://www.summitracing.com/search/...armonic-Balancer-Repair-Sleeves/?autoview=SKU

I also have changed more front covers on small block Chevys than i could count, doing cam changes in the car. It is always helpful if you can lower the pan a little. I have done it many times without lowering with no oil leaks. Don't be fooled into thinking that you are doomed to have oil leaks unless you pull your engine. Millions of them have been done that way.

On things I have worked on most oil leaks on a cork gasketed pan could be traced to the pan bolts being overtight, dimpling the pan. Same goes for the front cover. A little #2 permatex seems to help around the crank seal on the front cover before installing it. I think it also works better than silicone on the paper gasket on the cover but have used either with success.

Good luck, happy wrenching!

I will go along with you on your procedure I too have done this back in the day to without removing the pan . I would raise doubt about doing any timing on the timing cover The reason why this job poses difficulty is because you are compressing the rubber gasket in the bottom of the timing cover . I have done it without loosening the pans bolts and have had success . Most of the times I have done ths was when it was hot out and you have a better chance of compressing the rubber gasket .

 

[John_S]

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

He already used a new balancer and it shreaded again after a few hours. Something is drasticly wrong. Maybe the pan got bent when the last seal was replaced. It would be scarey if the crankshaft on a new reman has that much play to shread the seal.

 

[joewithaboat]

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

He already used a new balancer and it shreaded again after a few hours. Something is drasticly wrong. Maybe the pan got bent when the last seal was replaced. It would be scarey if the crankshaft on a new reman has that much play to shread the seal.

Thanks to John for getting us back on track after bantering back and forth about cover changes with or without engine removal. :redface:
Possible causes...

-I have seen crank snouts get bent by installing the balancer without the proper tool, as mentioned above its not a hammer.

-I guess it is possible to have the dowel pin and c/l of the crank seal out of spec. You could drill out the cover where it meets the pins.

-wrong crank.... I have no personal experience here but see this link on odd crank differences, apparently made in different places. see link http://hotsixes.com/index.php?option=com_content&view=article&id=14&Itemid=12

-main bearings wrong or wrong clearances, or possibly spun...
I have a brand new set of rod bearings that were marked .010 over sized, were sealed when i got them, and there is 2 pair of std. in the box. I tossed the receipt and local private owned parts store wouldn't take them back. They never got anymore of my business.

My money is on a bent crank snout.... need to mount a dial indicator and crank it over!

 

[Jmunk]

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

Does the 4.3L use a press fit crank pulley ? If so then the pulley may have been pressed on too far. I can not recall if the pulley use a bolt to secure them to the crank which would not make the installation depth a issue. A bent crank snout is a very possible cause. I always put some grease on the lip of the crank shaft seal that contacts the pulley to avoid a situation where the seal runs dry and tears.

 

[Technorunner]

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

A longshot. But as i understand it this is a pretty new engine with few hours.
On other engines i have seen this problem when they forgot 1 half of the crankshaft berings.
i cant speek for this engine but in a inline 6 cyl. its a really long shot and i dont hope you have that fault. On those engine i have found this problem the symptom have been the same. on idle you haven`t seen the dampner move. But under load the crankshaft will flex.

 

[joewithaboat]

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

A longshot. But as i understand it this is a pretty new engine with few hours.
On other engines i have seen this problem when they forgot 1 half of the crankshaft berings.
i cant speek for this engine but in a inline 6 cyl. its a really long shot and i dont hope you have that fault. On those engine i have found this problem the symptom have been the same. on idle you haven`t seen the dampner move. But under load the crankshaft will flex.

In a 4.3 i think there would be no way to maintain oil pressure if that were the case. I'm on-board with the wrong size or spun bearings though.

 

[RobOp]

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

Update on oil leak -

This weekend I put in a new seal, the new balancer and it's still leaking like crazy under load. I got my seal installation and alignment tool and checked the timing cover alignment, it appears to be perfect, the tool slides over the crankshaft easily and looks to be perfectly centered on the seal when it goes on.

I am going to try the old balancer with a speedy sleeve on it this next weekend, I'm wondering if the added thickness of the sleeve will help it to seal. A long shot but worth the couple hours to try.

I am having a difficult time getting a good runout measure on the crank sount with the engine in the boat. I've got a dial indicator with a magnetic mount, but I can't get it to stay put, I need some kind of mount that I can hard mount. All machinests I talk to say they have never tried to measure runout with the crank in the engine, they all do it in a lathe.

I worry that my greatest fear is coming true, a bent crankshaft. I've heard that if the reman crank came out of a car that went through a hard front end collision it may have likely bent the crank. If the Mercruiser reman shop did not check runout on the snout this could be the reason for a bent crank.

Soon I will have to decide if I want to pull the engine and replace the crankshaft or eliminate all the bad Mercruiser Reman juju and put in another long block. Any opinions? Besides Mercruiser who makes a good longblock?

 

[Technorunner]

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

but if it was bent you would have seen a leak even on idle right? And wouldent you almost be able to se the wobbling on the balancer?
It sounds more and more like somthings wrong with the bearings. As joe said if it would show on oil pressure if one half is gone then perhaps wrong sized. But as i said before i Really dont hope for it. Can you put a crow bar any place in the engineroom, and put under the balancer and push the balancer upwards and downwards to see if you got any movment in the crankshaft?

 

[RogersJetboat454]

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

I worry that my greatest fear is coming true, a bent crankshaft. I've heard that if the reman crank came out of a car that went through a hard front end collision it may have likely bent the crank. If the Mercruiser reman shop did not check runout on the snout this could be the reason for a bent crank.

Uhh yeah.. but unless that crank had absolutely spotless rod/main journals, it would have been put on a lathe to machine the journals down to specs, and someone would have hopefully noticed that the crank isn't running true considering the snout is one of the bit's that get stuck in one of the chucks of the lathe. The only real possiblity for damage would be an after the fact (I.E. someone droped the crank on the ground, and the snout took the hit, or the crank was installed in the block, and the snout took a hit).

Let's go back for a second...
Is the seal physically getting chewed up, or is it blowing out? In other words, is there a possiblity that excessive crank case pressures are blowing this seal out?

 

[RobOp]

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

but if it was bent you would have seen a leak even on idle right? And wouldent you almost be able to se the wobbling on the balancer?
It sounds more and more like somthings wrong with the bearings. As joe said if it would show on oil pressure if one half is gone then perhaps wrong sized. But as i said before i Really dont hope for it. Can you put a crow bar any place in the engineroom, and put under the balancer and push the balancer upwards and downwards to see if you got any movment in the crankshaft?

I see no significant wobble in the crankshaft, no more than the other engine.

I didn't use a crowbar, but I've grabbed the end of the crank and lifted up and down on it, no play what so ever.

 

[RobOp]

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

Uhh yeah.. but unless that crank had absolutely spotless rod/main journals, it would have been put on a lathe to machine the journals down to specs, and someone would have hopefully noticed that the crank isn't running true considering the snout is one of the bit's that get stuck in one of the chucks of the lathe. The only real possiblity for damage would be an after the fact (I.E. someone droped the crank on the ground, and the snout took the hit, or the crank was installed in the block, and the snout took a hit).

Let's go back for a second...
Is the seal physically getting chewed up, or is it blowing out? In other words, is there a possiblity that excessive crank case pressures are blowing this seal out?

I thought about the possibility that the engine had been dropped during the installation but I see no damage to the tins or any scrapes on the paint.

I also thought about blow-by. The first two seals were chewed up, the one from this weekend still looks OK but still leaking. Would an engine still idle and run smoothly with a set of blown rings on one cylinder? As I've said before, the engine seems to idle and run fine. Both valve covers are vented to the flame arrester (no PCVs), I've pulled the elbows out of their grommets in the valve covers and listened to the noise on each, they sound about the same. Is there another way to detect excessive blow-by or excessive crankcase pressure.

On the quicksilver remanufacturer sticker is says:
Bore O.S. STD
Main Brgs. STD
Thrust Width STD
Rod Brgs. STD

It looks like the crank has not been turned. Am I wrong?

P.S. - Oil pressure is fine, reads about 40 at high idle and cruise.

 

[Don S]

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

Are you sure it's leaking at the seal and not a pin hole rusted through the timing cover?

 

[RogersJetboat454]

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

I thought about the possibility that the engine had been dropped during the installation but I see no damage to the tins or any scrapes on the paint.

I also thought about blow-by. The first two seals were chewed up, the one from this weekend still looks OK but still leaking. Would an engine still idle and run smoothly with a set of blown rings on one cylinder? As I've said before, the engine seems to idle and run fine. Both valve covers are vented to the flame arrester (no PCVs), I've pulled the elbows out of their grommets in the valve covers and listened to the noise on each, they sound about the same. Is there another way to detect excessive blow-by or excessive crankcase pressure.

On the quicksilver remanufacturer sticker is says:
Bore O.S. STD
Main Brgs. STD
Thrust Width STD
Rod Brgs. STD

It looks like the crank has not been turned. Am I wrong?

P.S. - Oil pressure is fine, reads about 40 at high idle and cruise.

OK.. sounds like you have crankcase ventilation covered.
By the sounds of the reman tag, the crank installed was either pristine, or new.

Is there a possibility that the timing cover is not holding the seal square to the crank? In other words, either the cover was stamped incorrectly, or is pushed in, and the seal is biased in one direction. Do you happen to notice 1 part of the seal getting chewed up in peticular (top, bottom, left, right) or is it pretty much the entire seal getting chewed up equally?

 

[90stingray]

Might be a dumb question... are you using a coat of oil on the seal to lube it up? Sounds like they are going on dry, if they only last a few minutes.

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