oil leak - The 1947 - Present Chevrolet & GMC Truck Message Board Network

68bbc/20 · 12-07-2021, 09:49 PM

has anyone ever had an oil leak from the threaded hole for the z-bar pivot ball shaft? it appears to be worst when the engine is shut off and not under pressure while it's draining. thanks for your help on this!

**kwmech** · 12-08-2021, 01:56 AM

All of the Z bar holes I've seen are a blind hole and have no connection to the oiling system unless you have the pivot ball in the oil galley port and have somewhat cross threaded the pivot into the pipe plug hole

68bbc/20 · 12-08-2021, 08:04 AM

that's what I thought too! but it has oil leaking out of it because it doesn't thread all the way in leaving a couple threads exposed. I also pulled the pivot ball off an old 283 that has been setting on the passenger side for years and it had dark motor oil
on the threads and inside hole also.

68bbc/20 · 12-08-2021, 08:08 AM

it's in the same hole the 283 had it in, if it was in the wrong hole nothing would line up and or function properly.

**Ol Blue K20** · 12-08-2021, 08:43 AM

I would like to see pics if you'll post a couple.

68bbc/20 · 12-08-2021, 10:15 AM

Ol blue, pm me your phone number and i'll send you some pic's this evening after I get home from work. I've tried to post pictures before and can't seem to get them to post on here. thanks

**kwmech** · 12-08-2021, 11:11 AM

It is supposed to thread all the way in and tighten down like a bolt. You're in the wrong hole.

68bbc/20 · 12-08-2021, 02:31 PM

there is only on hole to put in beside the oil dip stick hole. z-bar lines up and pivots correctly. it doesn't thread all the way in and tighten up to seal it off is the problem. i'll pull it out and shorten it up so that it does. I've just never seen one that leaked before, especially draining back down with the engine off and not under pressure from the oil pump. engine is a brand new rebuild with about 30 miles on it and that's definitely where it's leaking from.

**Accelo** · 12-08-2021, 04:10 PM

Possibly you have a early Nova block. There are some rare exceptions to the SBC platform.

RustyPile · 12-08-2021, 05:36 PM

Quote:

Originally Posted by 68bbc/20

there is only on hole to put in beside the oil dip stick hole. z-bar lines up and pivots correctly. it doesn't thread all the way in and tighten up to seal it off is the problem. i'll pull it out and shorten it up so that it does. I've just never seen one that leaked before, especially draining back down with the engine off and not under pressure from the oil pump. engine is a brand new rebuild with about 30 miles on it and that's definitely where it's leaking from.

No, that is not the problem.. Normally the hole for the ball pivot doesn't open into an oil passage, so there's nothing to "seal off". it's possible the block has developed a crack between that hole and an oil passage and is allowing oil to seep out.. Do not shorten the threaded part of the ball pivot.. There's a lot stress load on that part and it needs all the threads intact. If the shank doesn't go all the way in and allow the shank to seat against the block it's probably because the hole is partially filled with debris.. Clean it out..

**pjmoreland** · 12-08-2021, 06:39 PM

A 350 engine I'm rebuilding right now had only the rear hole (#1) drilled for the Z bar ball mount, so I drilled and tapped the front one (#2). The rear hole passes all the way through the block and exits back by the flywheel. The front hole is blind. If it were drilled too deep, it would break through into the water jacket. That third hole has a pipe thread for a plug.

**pjmoreland** · 12-08-2021, 06:52 PM

A 350 engine I'm rebuilding right now had only the rear hole (#1) drilled for the Z bar ball mount, so I drilled and tapped the front one (#2). The rear hole passes all the way through the block and exits back by the flywheel. The front hole is blind. If it were drilled too deep, it would break through into the water jacket.

12-08-2021, 08:04 AM	#3
68bbc/20 Registered User Join Date: Dec 2018 Location: greencastle indiana Posts: 105	Re: oil leak that's what I thought too! but it has oil leaking out of it because it doesn't thread all the way in leaving a couple threads exposed. I also pulled the pivot ball off an old 283 that has been setting on the passenger side for years and it had dark motor oil on the threads and inside hole also.

12-08-2021, 08:08 AM	#4
68bbc/20 Registered User Join Date: Dec 2018 Location: greencastle indiana Posts: 105	Re: oil leak it's in the same hole the 283 had it in, if it was in the wrong hole nothing would line up and or function properly.

12-08-2021, 08:43 AM	#5
Ol Blue K20 Proprietor of Dale's Corner Join Date: Nov 2012 Location: Vacaville , CA Posts: 15,883	Re: oil leak I would like to see pics if you'll post a couple. __________________ "Some Days Chickens And Some Days Feathers" Dale XNGH ECV Sam Brannan 1004 R.I.P. 67ChevyRedneck R.I.P. Grumpy Old Man

12-08-2021, 10:15 AM	#6
68bbc/20 Registered User Join Date: Dec 2018 Location: greencastle indiana Posts: 105	Re: oil leak Ol blue, pm me your phone number and i'll send you some pic's this evening after I get home from work. I've tried to post pictures before and can't seem to get them to post on here. thanks

12-08-2021, 11:11 AM	#7
kwmech Senior Member Join Date: Mar 2003 Location: Colfax-California Posts: 8,408	Re: oil leak It is supposed to thread all the way in and tighten down like a bolt. You're in the wrong hole.

12-07-2021, 09:49 PM	#1
68bbc/20 Registered User Join Date: Dec 2018 Location: greencastle indiana Posts: 105	oil leak has anyone ever had an oil leak from the threaded hole for the z-bar pivot ball shaft? it appears to be worst when the engine is shut off and not under pressure while it's draining. thanks for your help on this!

12-08-2021, 01:56 AM	#2
kwmech Senior Member Join Date: Mar 2003 Location: Colfax-California Posts: 8,408	Re: oil leak All of the Z bar holes I've seen are a blind hole and have no connection to the oiling system unless you have the pivot ball in the oil galley port and have somewhat cross threaded the pivot into the pipe plug hole Last edited by kwmech; 12-08-2021 at 11:11 AM.

12-08-2021, 02:31 PM	#8
68bbc/20 Registered User Join Date: Dec 2018 Location: greencastle indiana Posts: 105	Re: oil leak there is only on hole to put in beside the oil dip stick hole. z-bar lines up and pivots correctly. it doesn't thread all the way in and tighten up to seal it off is the problem. i'll pull it out and shorten it up so that it does. I've just never seen one that leaked before, especially draining back down with the engine off and not under pressure from the oil pump. engine is a brand new rebuild with about 30 miles on it and that's definitely where it's leaking from.

12-08-2021, 04:10 PM	#9
Accelo Senior Member Join Date: Mar 2015 Location: washington Posts: 2,189	Re: oil leak Possibly you have a early Nova block. There are some rare exceptions to the SBC platform.

12-08-2021, 06:39 PM	#11
pjmoreland Senior Member Join Date: Jan 2005 Location: CA Posts: 5,349	Re: oil leak A 350 engine I'm rebuilding right now had only the rear hole (#1) drilled for the Z bar ball mount, so I drilled and tapped the front one (#2). The rear hole passes all the way through the block and exits back by the flywheel. The front hole is blind. If it were drilled too deep, it would break through into the water jacket. That third hole has a pipe thread for a plug. Attached Images

12-08-2021, 06:52 PM	#12
pjmoreland Senior Member Join Date: Jan 2005 Location: CA Posts: 5,349	Re: oil leak A 350 engine I'm rebuilding right now had only the rear hole (#1) drilled for the Z bar ball mount, so I drilled and tapped the front one (#2). The rear hole passes all the way through the block and exits back by the flywheel. The front hole is blind. If it were drilled too deep, it would break through into the water jacket.



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