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1964 Skylark 300 c.i. V8 Timing Cover Stuck

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Hi All:

 

I had a leak in the water jacket gasket between the timing cover and the block, so I'm going to replace the gaskets and install a new water pump while I'm at it. This is probably not a new issue to many of you, but I'm dealing with snapped-off bolt heads. I'm not too concerned about the short ones on the water pump as I will deal with them after I get the timing cover off, but there's one four-inch bolt on the passenger side that goes through the cover and into the block. That one snapped off right at the head, and it seems to be welded (figuratively) to the timing cover. Consequently, I can't get the timing cover off. It won't budge a hair, even with a puller between the block and the timing case. I could exert more pressure on the puller, but I don't want to destroy anything. Note that all of the bolts that hold the timing cover to the block as well as the ones on the oil pan came out except for this one. I have two questions:

 

  1. Apart from applying heat to the case, is there anything else I should try to break this loose? I don't think that PB blaster is going to make its way far enough along the bolt to be much help, so absent other suggestions I will heat up the works with a torch.
  2. Given the possibility that the timing cover will be damaged during the process, can anyone recommend a source for a replacement timing cover? I know of several sources out there like TA Performance, but I'd appreciate hearing from someone who has personal experience with one of the aftermarket covers. Quality trumps price.

 

Thanx in advance for your help. We've had some very nice days here recently and It's killing me to have the Buick off the road.

 

Jim

 

 

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First, be certain you have every other bolt out of that cover.  The big block cars have a bolt tucked into the deepest recess near the oil pump.  I am not sure if your 300 has that bolt, but it's virtually hidden on the big blocks. 

 

Next, if you have access to a trans dipstick on another car, heat that car to operating temperature, and then dribble some hot transmission fluid on the opening for the snapped off bolt.  This should be done for a few days in a row, to give the fluid a chance to work in and deteriorate the bond between that broken bolt and the cover.

 

Mostly, just take your time.  If you rush it, you will lose that cover.  If you give it a chance then you can likely save that cover.

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If the bolt is on an edge drill  the side of the cover down to the bolt and introduce your penetrating fluid there.  If that does not work tap and install a grease zerk and try to pump grease while heating.

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John and Old Tank:

 

Thank you for the suggestions. First, there was a bolt sort of hidden between the oil pump and the oil pan that's not easy to see unless you get under the car or look at it head-on. Yep, all the bolts are out. I have a nice, clear view of the cover because I removed the radiator. I hadn't heard of using transmission fluid to free up stuck bolts, but it's worth a try. I'm not sure that the stuff will migrate along the bolt since the bolt is horizontal and there's about four inches of travel required but hey, I'm willing to give it a go. As for drilling along the bolt, that's my option of last resort just before I exercise the nuclear option with the torch.

 

Given that it'll take some time to treat the bolt and my limited time to work on the car it'll be a couple of weeks before I have results. I will be sure to let you guys know how I make out.

 

Jim

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There is a study that showed Trans fluid and Acetone mix is many times better than PB Blaster.  But I have had experiences where soaking those bolts with the hot trans fluid works pretty well.  BTW, if you do go to heat something there I'd be careful you don't melt that aluminum cover.  I'd be tempted to try and heat the bolt itself with out getting anything to glow.  Just heat, trans fluid soak, let cool, and repeat. 

 

One more thing.  I have done a fair share of timing chain covers.  Usually I use a long handle with a thin flat blade screwdriver, and a rubber mallet to break the seal at the top edge, just behind the distributor opening.  There and then if I can get a clean shot at the sides by the fuel pump opening and on the opposite side too.  Just enough hammering on the screwdriver flat against the engine block,  to avoid roughing up the cover. 

 

  

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Even application of modest heat (i.e. propane torch) to the cover in the vicinity of the bolt may help.  Just warm the area, apply some trans fluid, PB Blaster, or other and let it cool.  Lather,rinse, repeat...  The heat/cool cycling will help to break the corrosion bond.

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Let the penetrating oil to penetrate.  It make take several days with new application of oil everyday.   Apply the penetrating oil into the bolt hole were the bolt head broke off.   I'm sure that is good and rusted up because breaking a steel head bolt is a sure indicator of that.   Second, apply the penetrating oil around the mating surface of the pump/chain cover housing.  Allow this is penetrate for days.  

 

Yes, rusting steel parts can appear to be welded together.  I replaced the t-belt on my KIA.  KIA in it's engineering wisdom has the crank gear fitted into the balance pulley.  Took a week of penetrating oil and rubber mallet to get the gear off the pulley.  Needless to say the gear seats inside the pulley less than a quarter inch.  Yet both parts appeared to be welded together as one solid piece. Keep in mind these two parts were assembled together only 6 years ago.    Your Buick assembled decades ago. It will take time for the oil to do the trick.  

 

Key here is time for the oil to penetrate.  Patience.  Use light heating at the broken bolt area as the last resort.    

Edited by avgwarhawk (see edit history)
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Yep, gonna take all your advice. I will start tomorrow with the process, and if my work schedule permits I'll treat the cover over the course of next week and hopefully I might get it off undamaged by next weekend. I have an acetylene torch that I'll use to gently heat the area to hopefully move things along. Hotter than propane but not hot enough to easily damage the aluminum like oxy-acetylene would. I agree, patience is the key.

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Success! The cover came off without damage. Repeated cycles of heat, ATF/solvent, a drill, and pressure via a harmonic balancer pulley placed in between the block and the water pump mounting boss did the trick. After several cycles of heat and ATF over the course of several days I managed to get the timing cover to start wiggling, and that was encouraging. I hit a snag though, when continued efforts over the course of two more days failed to get the cover to budge beyond the wiggle stage. I noticed that what little movement there was could be seen where the cover meets the block, and the end of the bolt by the water pump showed no movement at all. I figured that was where the problem was, so I decided to drill out the bolt. I didn't want to chance ruining the cover, so I drilled only up to the point where the water pump met the cover. That did the trick. It'll be awhile before I get it all back together. I have to get the stud out of the block, (which should not be as much of a challenge since I can use a hotter torch there if need be), separate the water pump from the case (all of the remaining bolts but one broke off and the pump is stuck to the cover, and then I have to order a new set of bolts.

 

Guys, thank you very much for your suggestions and encouragement.

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Good news! Some times it just takes time for the penetration oil to do the job. Heat to work it's magic. Some unconventional tools. Most of all patience. Glad it all worked out well.

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Nice!  Most bolts can be sourced at your local ACE (or other) hardware store too

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One of the neatest things for removing a broken stud is left hand drill bits.  They work just like regular bits (start small and increase the size several times) but because they cut counter clockwise every turn of the bit works on loosening the stud.

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Thanx for the tip, Tin. I have a set of those, around here we call them easy-outs. I hope not to need them since most of the bolt remains sticking out of the block and I'll be able to use my stud extractor on it. That process should go fairly quickly, since I'll be able to use the oxy-acetylene torch to heat things up without worrying about ruining the aluminum case.

 

You probably know this already, but you live in a very beautiful part of the world. I was in the City of Vancouver back in '77. Loved Gastown. Didn't make to the island, though.

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When you put it back together use plenty of Anti-Seize. That way you or the next owner of the car can get it apart 30 years down the line.

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I sure will, Bill. I have a supply of anti-seize that I use for my motorcycle spark plugs, O2 sensors and various other things on the family cars.

 

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Here is another thing to consider. 

You need sealer on the bolts that go into the block. And antiseize on the portion of the bolt that sits in the timing chain cover.  So in order to prevent antiseize from compromising the sealer I recommend a thin layer of antiseize is paint brushed onto the length of the bolt. Then install after the sealer is put on the threds.

 

Edited by JohnD1956 (see edit history)
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JohnD: I had planned to use anti-seize on along the length of the bolts and also on the threads, but would you please explain the purpose of the thread sealer? I've never used it before and I'm not sure why you recommended it. Thanx, Jim

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The holes in the block for the bolts that John is referring to are open to the coolant passage and will weep unless thread sealer is used.

Edited by EmTee (see edit history)
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Thanx EmTee. I didn't realize that the long bolts in the block were open to the coolant passage. I get it now.

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Got it John, thanx. I hope to have it all back together and ready for the road in a couple of weeks. Now that it's all apart I have to clean everything up, pick up some bolts and get everything back on the engine. Not a very big job, but I'm only going to have an hour here and there to work on it.

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Don't forget your thermostat.  There is no easier time to replace that, and get it centered during mounting, than right now.  And those bolts need sealer also. 

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