Where's my motorheads at?

williambmac said:
I had to go digging thru the garage to see if I had some parts for a forum member. I pulled out a 4.0 block that I will eventually using for a stroker build. The is no oil passage in the block that lubes the Synchronizer. there is also a guide in the block right above the oil pump for the synchronizer shaft to pass thru.
The way I see it is either there is an issue with the cam, the drive gear or perhaps the synchronizer itself. By looking at the cam and cam bearing location, there is nothing supporting the cam itself by the gear. There is quite a distance between the #2 and #3 cam bearing (outlined in red) So perhaps when the first synchronizer seized and the customer tried restarting it, maybe it bound up and bent the cam?
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That helps a bunch, thanks.
 
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williambmac said:
I had to go digging thru the garage to see if I had some parts for a forum member. I pulled out a 4.0 block that I will eventually using for a stroker build. There is no oil passage in the block that lubes the Synchronizer. there is also a guide in the block right above the oil pump for the synchronizer shaft to pass thru.
The way I see it is either there is an issue with the cam, the drive gear or perhaps the synchronizer itself. By looking at the cam and cam bearing location, there is nothing supporting the cam itself by the gear. There is quite a distance between the #2 and #3 cam bearing (outlined in red) So perhaps when the first synchronizer seized and the customer tried restarting it, maybe it bound up and bent the cam?
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Wow ! There's a Kentucky mile between the journals, If a cam can deflect and hold said deflection this could be the math that
would allow that scenario ! Blaine, is there a low effort way to set up a dial indicator and index the potential runout measuring each tooth on the cam gear and rotating the engine?
 
Well, that should teach me not to assume. I assumed that since there was a hole in the side of the synchronizer, it was an oil feed hole. I looked at my new Crown OPDA ('05) and there is no "oil" hole at all. So how do these things get oiled? The upper bearing, whether '04 and older or '05-'06, seems to have no way of getting oil. Or am I just assuming that upper bearing is way up in there?
 
OldBuzzard said:
Well, that should teach me not to assume. I assumed that since there was a hole in the side of the synchronizer, it was an oil feed hole. I looked at my new Crown OPDA ('05) and there is no "oil" hole at all. So how do these things get oiled? The upper bearing, whether '04 and older or '05-'06, seems to have no way of getting oil. Or am I just assuming that upper bearing is way up in there?
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If they had bearings this likely wouldn't be an issue. Pretty sure without cutting one open they run a bushing.
 
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mrblaine said:
If they had bearings this likely wouldn't be an issue. Pretty sure without cutting one open they run a bushing.
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freedom_in_4low said:
Pretty sure if they had bearings most of us wouldn't really know or care what OPDA even stands for.
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True. I tend to lump bushings in the "bearing" family (as in babbitt bearings). Still, how do those bushings get lubed? And where is the top one, in the lower part of the housing, or up high?

Not that it is pertinent to mrblaine's current question. Sorry.
 
Come to think of it, @mrblaine, maybe you should go ahead and cut one of those synchronizers open. If the bushings look cooked, that could tell us something. Or if the cam was bent and shoving the shaft sideways, it should have worn one side of the bushings badly.
 
OldBuzzard said:
Well, that should teach me not to assume. I assumed that since there was a hole in the side of the synchronizer, it was an oil feed hole. I looked at my new Crown OPDA ('05) and there is no "oil" hole at all. So how do these things get oiled? The upper bearing, whether '04 and older or '05-'06, seems to have no way of getting oil. Or am I just assuming that upper bearing is way up in there?
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I believe if you were to cut one open, you would probably find a small spiral groove machined into either the shaft or the housing. The spinning motion would force oil up into the housing. I do have a beat one that is from an 05. I’ll cut it open tomorrow.
 
The 05 and 06 OPDAs are "special." They are essentially the old distributor base with a tone wheel on top, but DC managed to screw it up by sealing the upper bushing from the engine oil and using a "lubed for life" bushing that eventually dries out and seizes. All they had to do was use the old distributor design unmolested, but no...
 
JKP said:
The 05 and 06 OPDAs are "special." They are essentially the old distributor base with a tone wheel on top, but DC managed to screw it up by sealing the upper bushing from the engine oil and using a "lubed for life" bushing that eventually dries out and seizes. All they had to do was use the old distributor design unmolested, but no...
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I replaced the distributor in my 99 at 25,000 miles due to the bushing dying a horrible death.
 
I always worry when I see a "lubed for life" bushing. Who's life? The device? The vehicle it goes in? Mine?
Same with lifetime guarantee. Who's life? Life of the product might be expected to be a year.
 
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mrblaine said:
I replaced the distributor in my 99 at 25,000 miles due to the bushing dying a horrible death.
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Interesting. I replaced the distributor in my '92 at around 220K mi because it was cheaper to get the whole distributor than it was to buy the cam sensor inside it. Shaft rotated smoothly.

Any idea why yours died such an early death?
 
JKP said:
Interesting. I replaced the distributor in my '92 at around 220K mi because it was cheaper to get the whole distributor than it was to buy the cam sensor inside it. Shaft rotated smoothly.

Any idea why yours died such an early death?
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Made the same noise as a bad alternator bearing so I assume that the bushings went bad.
 
Probably not too helpful but I've had folks tell me there's no way to bend a cast camshaft; they say they only break. I've seen cast & ADI cams bend and not break in small block Chevys. I'll see if can find photos.
 
What if the owner is running oil that is too thick or possibly an aftermarket oil pump set too high? This would cause excess force on the gear at RPM.
 
While not an OPDA, I had something very likely related to this happen with my distributor way back when my 4.0 was still a 4.0. Killed one distributor and ejected another into the underside of my hood while driving (obviously killing it as well).

mrblaine said:
That's because the fucktards haven't shown up yet.
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Who's that directed at?
 
SkylinesSuck said:
While not an OPDA, I had something very likely related to this happen with my distributor way back when my 4.0 was still a 4.0. Killed one distributor and ejected another into the underside of my hood while driving (obviously killing it as well).
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The drive system is the same.
SkylinesSuck said:
Who's that directed at?
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The fucktards.
 
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J Harding said:
What if the owner is running oil that is too thick or possibly an aftermarket oil pump set too high? This would cause excess force on the gear at RPM.
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Neither of those are applicable. The oil has not been changed from what the previous owner was using, and the oil pump is also the same.
 
Was the marks on the oil pump drive tang made by a tool. Just wondering.
 
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