9N exhaust manifold studs

[Shadowfax419]

Working on getting Gertrude back together...had her running then found out my exhaust was leaking at #4. When taking it off, I realized I had a leaking head gasket...Broke her down, inspected all while head off. It all looks good, no scarring or marks on the cylinder walls. Head is flat and looks good. The problem now is that there were 2 bolts and two studs used on the manifold. It appears that one of the studs broke off in the block. Looking for suggestions on removing and repairing broken stud. I searched and searched for studs 1 5/8 according to Bruce (Va). The only ones I was able to find was from Ace hdw, and they're 2 1/2 long. The threads that go into the block are 1 1/4 and the threads to hold the manifold are 3/4. According to what I read, (posted by Bruce (Va) I think, these studs go into the water jacket and don't need to be too long. My question, is it ok to double nut these and cut them off to the correct length, then take off the nuts to make sure the threads are fine? Also, sealer or not? Read on separate threads that it is/is not needed. Will take what is said on this forum as the definitive answer!

 

[Tim PloughNman Daley RIP]

If you have two broken studs, that means you were only using two fasteners to mount the manifold? #1 problem is getting the broken studs out of the block without mucking up the threads. I highly advise to take to a good machine shop where they have the right stuff to do the job. You are not going to drill the broken studs out with a hand drill if that is what you're thinking. Studs are hardened steel. Block is cast iron. If drill walks off you will destroy the threads in block. Let a professional do it. #2: Are you replacing with a new manifold? Highly advised. Your exhaust manifold gets hottest at the #4 port (nearest dash) and once the cast iron wears a channel on it, time to replace with new. Forget trying to reuse old one. R&R'g the exhaust manifold is not a difficult job, mostly time consuming, as many parts must be removed first. Replace it now while you have it all apart. #3: You can get the correct manifold stud kit from nnalert - see LINK below. OEM stud is p/n 88403-S which is a nominal 7/16 size. Length was 1-5/8 but a 1-3/4 sold today will work. NOTE: STUDS are made with a coarse end and fine thread end. The coarse end always is the one that mates with the cast iron block/part. The fine thread always accepts the hex nut fastener. The 9N-9425 Exhaust Manifold is a combo intake/exhaust design. The carburetor is mounted to it with two 5/16 studs on the carb flange mount. Many dudes don't know this and end up inserting the wrong end into the cast iron part. Probably what happened with your broken studs. I've repaired good manifolds that customers had put wrong carb stud ends in with heli coils. nnalert will have all the parts you need. Plan on draining some coolant first as once stud is removed, some may spew out from water jacket. A new manifold often comes with the three paper gaskets required - two on manifold to block and one on carb flange mount. Use new ones. Not all suppliers are equal. It matters where you buy from. The manifold mount with the 7/16 studs uses BRASS HEX NUTS. The extra 1/8 stud length won't hurt but you may need a deep well socket when installing. Use a good 6-PT, thin wall, deep well socket. TORQUE, often misunderstood and done incorrectly anyway, is spec'd at 27 ft/lbs for the 7/16 BRASS hex nuts if you think you need to torque them. I use my built-in torque-o-meter - my own hand strength - to do mine with no problems ever. Also, at this time, think about the condition of the muffler assembly. If it is due to replace, do it now. Replace exhaust pipe with a new clamp and bolt kit regardless. Two 5/16-18 steel hex head bolts required and use a BRASS 5/16-18 HEX NUT and steel lockwashers. The two-piece clamp goes on with the large end down. Once you get the broken studs out and chase the block threads with a 7/16-14 tap, plan on replacing these wth all new parts:

9N-9425 - EXHAUST MANIFOLD; some include the 3 paper gaskets: 9N-9448 (2) and 9N-9447 to carb flange (1)

MANIFOLD STUD - 7/16-14 X 7/16-20 X 1-3/4L, P/N 88403 KIT; 4 REQUIRED

MANIFOLD HEX NUT KIT - BRASS: 7/16-20 33816 KIT; w/ 7/16 STEEL LOCKWASHERS, 4 REQUIRED

(optional if needed) CARBURETOR 5/16-18 X 5/16-24 x 1-1/4L STUDS, 88371 KIT, includes 5/16 lockwashers and 5/16 -24 Hex Nuts - 2 each required

EXHAUST PIPE CLAMP: 9N-5251 KIT includes 5/16 Steel Hex Head Bolts, 5/16 steel lockwashers, and 5/16 BRASS Hex Nuts; 2 each required.

If radiator needs flushing and new coolant, now is the time to do it. Ditto for your water pump as well.


Tim Daley (MI)
MANIFOLD STUD

 

[Shadowfax419]

Thanks, Tim for the lengthy and informative reply. Here's an update. The third stud from front was not broken off. I carefully looked at the studs that came out when intially removing the manifold. The stud was actually a bolt which was in such bad shape, I could hardly make out the threads. I cleaned up the stud hole in the block and it appears that someone has tapped it to 1/2 course threads. I cleaned the threads up with a tap and it is indeed 1/2! What are my options? You mentioned helicoils. Where can I source them, I looked on nnalert and couldn't find them. I would think I could get a helicoil threaded at 1/2 to 7/16 somewhere. Thanks again for the help!

 

[wore out]

Where you are going to get into trouble is (ASSUMING the threads in the block are 1/2'' NC) is that 1/2'' NC is 13 threads per inch and 7/16 NC is 14 threads per inch and with a threaded insert with such a small difference between I.D. and O.D. can't accommodate that.

What you could do is get a ''stepped'' stud that's 1/2'' on one end and 7/16'' on the other.

They can be tough to find but could be easily made by anyone with a lathe.

One example is Dorman 675-038, some $4 each, but you have to buy a 10-pack!

 

[Dave G9N]

This thread has a lot more responses in Classic view than modern view.

A 7/16-14 Key locking insert can be bought with a 5/8-11 outside thread. The tap drill size for 5/8-11 is 37/64 according to McMaster. Other sites said 17/32. That should clean up a bad 1/2-13 hole well enough. Keenserts are stronger than helicoils and won't back out.
https://www.mcmaster.com/products/~/black-phosphate-steel-key-locking-inserts/

This is an older thread, same subject, same experts. https://forums.yesterdaystractors.com/viewtopic.php?t=1314669

This post was edited by Dave G9N on 11/10/2023 at 10:33 pm.

 

[HFJ]

(quoted from post at 03:23:18 11/11/23) This thread has a lot more responses in Classic view than modern view.

tim's post does not appear in modern because he included a link to a blocked site and classic and modern handle the blocking differently.

in modern, the post just doesn't show.
in classic, the post is displayed but the link is disabled :lol:

 

[HFJ]

(quoted from post at 12:37:13 11/11/23) classic and modern handle the blocking differently.

ps: without knowing more about Chris, i'd say he's no more than two miracles short of sainthood. certainly, getting classic and modern to play together as well as they do qualifies as one.

 

[John P.]

You can still get them new from New Holland under part number 88403S2.

They are $13.05 each.

 

[wore out]

(quoted from post at 15:02:55 11/11/23) You can still get them new from New Holland under part number 88403S2.

They are $13.05 each.

He will have a tough time using one of those in the hole that has been drilled and tapped to 1/2''.

 

[Dave G9N]

(quoted from post at 10:45:56 11/12/23)

(quoted from post at 15:02:55 11/11/23) You can still get them new from New Holland under part number 88403S2.

They are $13.05 each.

He will have a tough time using one of those in the hole that has been drilled and tapped to 1/2''.

hat is why I mentioned Classic View. He has no way of knowing about the oversized hole unless he knows that there is a lot more information hidden here.

The 5/8" OD key lock inserts will work in the oversized hole to provide the correct thread size repair.

 

[Shadowfax419]

This thread has a lot more responses in Classic view than modern view.

A 7/16-14 Key locking insert can be bought with a 5/8-11 outside thread. The tap drill size for 5/8-11 is 37/64 according to McMaster. Other sites said 17/32. That should clean up a bad 1/2-13 hole well enough. Keenserts are stronger than helicoils and won't back out.
https://www.mcmaster.com/products/~/black-phosphate-steel-key-locking-inserts/

This is an older thread, same subject, same experts. https://forums.yesterdaystractors.com/viewtopic.php?t=1314669

This post was edited by Dave G9N on 11/10/2023 at 10:33 pm.

Thanks Dave for the reply. Jeesh, I hate being a noobie! Not sure of the classic/modern view thingy! I went into my profile to look for a setting but all I saw was the "Threaded view"setting. In this case not only do you have to lead this horse to water, but you might have to insert a straw in my mouth! What a dweeb! Anyway, back to the issue at hand, I purchased the key-lock insert from McMaster Carr 90245A035 along with the insert tool. Looks like something good to have for future use. It calls for a 37/64 drill bit and a 5/8-11 tap size. If I install this according to specs, will this insert restore the hole in the head back to OEM? If I insert a standard stud should this solve my leaking problem? Do I need to put any type of thread sealant on it? Thanks again, for all you guys' patience. I had to put Gertrude on the back burner during the holidays, but need to get her primed to work the garden in a couple of months.

 

[Dave G9N]

Thanks Dave for the reply. Jeesh, I hate being a noobie! Not sure of the classic/modern view thingy! I went into my profile to look for a setting but all I saw was the "Threaded view"setting. In this case not only do you have to lead this horse to water, but you might have to insert a straw in my mouth! What a dweeb! Anyway, back to the issue at hand, I purchased the key-lock insert from McMaster Carr 90245A035 along with the insert tool. Looks like something good to have for future use. It calls for a 37/64 drill bit and a 5/8-11 tap size. If I install this according to specs, will this insert restore the hole in the head back to OEM? If I insert a standard stud should this solve my leaking problem? Do I need to put any type of thread sealant on it? Thanks again, for all you guys' patience. I had to put Gertrude on the back burner during the holidays, but need to get her primed to work the garden in a couple of months.

This is where I have a problem with the new format. I am used to finding the last post at the end. Find it in the middle like this is hit or miss.

I have seen recommendations for oil and sealants. Ford didn't use anything but oil according to the gurus here. That tells me that for a brand new engine, nothing else is needed. I can't see the coolant making its way through the gasket and not much leaking out under the nut to the outside. Very slow leaks like that tend to cause just enough corrosion to self plug. I like the idea of using a sealant on the engine end of the stud. I like anti-seize on the exposed end. In the case of the stud, installing the stud with either oil or a sealant and anti seize on the nut would make for more friction on the end that you want to stay put and less on the nut when it needs to come off. I have been very unhappy with the frozen up fasteners when I skipped the anti seize and never had a problem caused by it when I used it. Being able to unscrew the nuts on an exhaust clamp is so much better than rounding the rust frozen ones off and having to resort to the angle grinder. What a long way to say, I know how to repair threads, but not enough to answer your question.

 

[Jim.ME]

This is where I have a problem with the new format. I am used to finding the last post at the end. Find it in the middle like this is hit or miss.

I have seen recommendations for oil and sealants. Ford didn't use anything but oil according to the gurus here. That tells me that for a brand new engine, nothing else is needed. I can't see the coolant making its way through the gasket and not much leaking out under the nut to the outside. Very slow leaks like that tend to cause just enough corrosion to self plug. I like the idea of using a sealant on the engine end of the stud. I like anti-seize on the exposed end. In the case of the stud, installing the stud with either oil or a sealant and anti seize on the nut would make for more friction on the end that you want to stay put and less on the nut when it needs to come off. I have been very unhappy with the frozen up fasteners when I skipped the anti seize and never had a problem caused by it when I used it. Being able to unscrew the nuts on an exhaust clamp is so much better than rounding the rust frozen ones off and having to resort to the angle grinder. What a long way to say, I know how to repair threads, but not enough to answer your question.

If you want to see the latest post at the end of the thread, make sure the Threaded View box is not checked in your preferences. Finding them mixed in, is the threaded view where they show after the post they are replying to. I believe Chris said all accounts were moved to the threaded view at the time of the changeover and that the user (you) had to make the change from the threaded view, if they wanted to see the threads like modern used to be (having the newest post at the end).

 

[wore out]

Thanks Dave for the reply. Jeesh, I hate being a noobie! Not sure of the classic/modern view thingy! I went into my profile to look for a setting but all I saw was the "Threaded view"setting. In this case not only do you have to lead this horse to water, but you might have to insert a straw in my mouth! What a dweeb! Anyway, back to the issue at hand, I purchased the key-lock insert from McMaster Carr 90245A035 along with the insert tool. Looks like something good to have for future use. It calls for a 37/64 drill bit and a 5/8-11 tap size. If I install this according to specs, will this insert restore the hole in the head back to OEM? If I insert a standard stud should this solve my leaking problem? Do I need to put any type of thread sealant on it? Thanks again, for all you guys' patience. I had to put Gertrude on the back burner during the holidays, but need to get her primed to work the garden in a couple of months.

I don't know how much ''meat'' is in that area of the block but a 5/8'' drilled and tapped hole would be AWFULLY big in that area.

I will again suggest a ''stepped stud'' with 1/2'' thread on one end and 7/16" thread on the other, which wouldn't require any further drilling and tapping of the block.

I'll even make you one, if you'd like!

 

[HFJ]

Not sure of the classic/modern view thingy!

no worries. modern view/classic view ceased to exist recently

 

[Tim PloughNman Daley RIP]

Working on getting Gertrude back together...had her running then found out my exhaust was leaking at #4. When taking it off, I realized I had a leaking head gasket...Broke her down, inspected all while head off. It all looks good, no scarring or marks on the cylinder walls. Head is flat and looks good. The problem now is that there were 2 bolts and two studs used on the manifold. It appears that one of the studs broke off in the block. Looking for suggestions on removing and repairing broken stud. I searched and searched for studs 1 5/8 according to Bruce (Va). The only ones I was able to find was from Ace hdw, and they're 2 1/2 long. The threads that go into the block are 1 1/4 and the threads to hold the manifold are 3/4. According to what I read, (posted by Bruce (Va) I think, these studs go into the water jacket and don't need to be too long. My question, is it ok to double nut these and cut them off to the correct length, then take off the nuts to make sure the threads are fine? Also, sealer or not? Read on separate threads that it is/is not needed. Will take what is said on this forum as the definitive answer!

Well, I advise to get manuals and do the job right. First your manifold is probably worn out at port #4 -as it gets the hottest. Forget double nutting, doubling gaskets, just do the job as instructed. You can get manifold studs here:

https://just 8n's/88403-S-Years-1939-52-Manifold-Stud-716-14-716-20-x-1-34

Tim Daley (MI)

 

[lha]

Working on getting Gertrude back together...had her running then found out my exhaust was leaking at #4. When taking it off, I realized I had a leaking head gasket...Broke her down, inspected all while head off. It all looks good, no scarring or marks on the cylinder walls. Head is flat and looks good. The problem now is that there were 2 bolts and two studs used on the manifold. It appears that one of the studs broke off in the block. Looking for suggestions on removing and repairing broken stud. I searched and searched for studs 1 5/8 according to Bruce (Va). The only ones I was able to find was from Ace hdw, and they're 2 1/2 long. The threads that go into the block are 1 1/4 and the threads to hold the manifold are 3/4. According to what I read, (posted by Bruce (Va) I think, these studs go into the water jacket and don't need to be too long. My question, is it ok to double nut these and cut them off to the correct length, then take off the nuts to make sure the threads are fine? Also, sealer or not? Read on separate threads that it is/is not needed. Will take what is said on this forum as the definitive answer!

When I replaced the oil pump dears on my 9n,a couple of the studs were bolts. Wanting to do it right,I went to an industrial supply in a very small Town near my house and they had some studs that were some industrial standard that I was told were more durable than grade 8 and fit well.

 

[Dave G9N]

When I replaced the oil pump dears on my 9n,a couple of the studs were bolts. Wanting to do it right,I went to an industrial supply in a very small Town near my house and they had some studs that were some industrial standard that I was told were more durable than grade 8 and fit well.

I don't know how much ''meat'' is in that area of the block but a 5/8'' drilled and tapped hole would be AWFULLY big in that area.

I will again suggest a ''stepped stud'' with 1/2'' thread on one end and 7/16" thread on the other, which wouldn't require any further drilling and tapping of the block.

I'll even make you one, if you'd like!

Could be important, without knowing the wall thickness, this is safer. It would be stronger if there isn't enough material. The hole for a 9/16" thread should clean up well enough before you tap. You are buying .03" more wall thickness.

On the other hand, the keensert will take a normal stud so the next replacement will be easier. It will be a head scratcher for someone who isn't expecting it.

 

[Shadowfax419]

Ok...about to give up on the old girl...I have drilled out the stud hole with the proper sized bit purchased from McMaster Carr. I put some sealant on the insert installed it and waited a couple of days for the sealant to set up. I then installed the manifold, tightening the new nuts to spec. I noticed the insert was not real tight and wiggled a little while installing the stud and tightening the nut. When adding water back into the radiator, it immediately started leaking out of the new manifold bolt. About ready to give up! Anyone have any ideas before I put my baby up for sale?