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G188D - Help needed! Working on my head and busted a nut!

Anthony Friot

Active Member
Joined
Feb 3, 2019
Messages
30
Location
Potsdam, NY, USA
While on the internet, I was looking around for information why my Case 480C backhoe will not start when under 50F without starting fluid. Over that, it starts really hard without the starting fluid. I found a service manual. Great! I was going through the tune-up mentioned because I thought it couldn't hurt, right? Well, upon re-torquing my head fasteners, a nut broke! WHAT! I was replacing the stud that holds the valve cover down when I heard a snap and felt something ricochet off my cheek. I was dumbfounded with the stud in my hand as to what just happened. Re-torquing the head fasteners has now left me with no way to work now because I need to hunt down a special nut to replace the one that broke AND the one I'm going to replace because I don't want the other one to fracture as I'm using the machine if I do not replace it.

I cannot find anyone who carries this nut anywhere on the internet through a Google search. Honestly, I did find one retailer who had them listed for about $75 each! No freaking way! I'll put a grade 8 nut on it and fashion a female bolt to turn on a few threads of what's left of the stud in the head.

My question is....Where can I find 2 NEW nuts A51114 (nut - head studs, 1/2" NC and 3/8" NC)? If they are not available, what would be suggested?

Thank you!
 

hosspuller

Senior Member
Joined
Aug 27, 2014
Messages
1,869
Location
North Carolina
Looks like it only holds the valve cover on... Weld two nuts together with a spacer between if needed.
Or ...
Get a "coupling nut" and modify the cover stud.
Or
you really want an animal called "reducing coupling nut"

Grainger has both types of coupling nuts in grade 5 & 8

If the head stud is long enough, a grade 8 nut, then a common coupling nut for the cover... for least cost.
 
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Tyler d4c

Senior Member
Joined
Mar 2, 2016
Messages
1,750
Location
Salix Pa
Help needed! Working on my head and busted a nut! That's a attention getter if I've ever read one
 

Anthony Friot

Active Member
Joined
Feb 3, 2019
Messages
30
Location
Potsdam, NY, USA
@ Tyler d4c: I was reluctant to use that subject header, but it was the truth.

@ thepumpguy: I tried to email dale weiss @ tractor stuff dot com and was bounced back as undeliverable. The website, tractor stuff dot com, redirects me to an auction website. He may have retired?

I called the local Case dealer. $90! For ONE!

@ hosspuller: We do not have a local Grainger store, but we do have Fastenal. Fastenal didn't have individual reducing connecting nuts (37845) in stock, but they did have a package of 10 (1137845) for $21.28 including tax.

I'll be testing one of the ASTM A563 nuts to see what kind of torque it will take prior to installing for good. Installed under the valve cover, it's bathed in oil regularly so I don't see it being corroded by atmospheric elements. The original does not appear very solid/hard so maybe the reducing coupler will suffice.

DSC_0008[1].JPG
 

Tinkerer

Senior Member
Joined
May 21, 2009
Messages
9,342
Location
The shore of the illinois river USA
Bad idea to re-torque those head bolts, unless you very recently had the head off. The motor prolly has low compression causing the hard starting.
You do not need that reducing nut.
Go to any hardware store and get 1/2 inch coupling nut.
Drill the valve cover hole to 1/2 inch and put a short piece of all thread in the new hole to hold the valve cover on.
Do not use those nuts to torque the stud in the block !
Dale is here !
Call or email him.
http://e-backhoeparts.com/
 
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hosspuller

Senior Member
Joined
Aug 27, 2014
Messages
1,869
Location
North Carolina
@ Tyler d4c: I was reluctant to use that subject header, but it was the truth.

@ hosspuller: We do not have a local Grainger store, but we do have Fastenal. Fastenal didn't have individual reducing connecting nuts (37845) in stock, but they did have a package of 10 (1137845) for $21.28 including tax.

View attachment 214685

Grainger is on-line too.

I wonder how the center of the Case nut was machined out. Looks like the diameter is bigger than both minor thread diameters. Unless, the nut starts out as a casting …
 

Anthony Friot

Active Member
Joined
Feb 3, 2019
Messages
30
Location
Potsdam, NY, USA
@ Tinkerer: I had not heard of re-torquing head fasteners that unless it was shortly after a new head gasket was installed. The service manual states re-torquing the head as part of the tune-up. I am not familiar with workings of dieselsand figured diesels require different attention than gasoline engines, so I went along with the service manual. The nut is used in the torquing sequence (#4 of 19) according to the service manual. As such, I don't know how I can replace the nut without using the replacement to torque the head down. Won't the lack of tension potentially allow head gasket leakage?

I have reached out to Dale Weiss for assistance.



DSC_0009.JPG 2020-04-07 (2).png
 

Tinkerer

Senior Member
Joined
May 21, 2009
Messages
9,342
Location
The shore of the illinois river USA
I guess I am old school so to speak. Why disturb the head bolts or studs unless there is an existing problem.
Your situation is a good example. I'm not criticizing you so don't be offended.
Ya I'm aware of the service manual. I only use those directions after a head has been off and run awhile. You do need the OEM nut. It is a hard SOG.
 

Anthony Friot

Active Member
Joined
Feb 3, 2019
Messages
30
Location
Potsdam, NY, USA
I have found that the new nuts are not in stock anywhere I checked, but prices are apparently ~$75 list price and the local dealer quoted me $90. I have found used nuts for $35, but I'm a bit stubborn and curious. I already purchased and retrieved the reducing coupling nuts. I have reassembled engine with the purchased coupling. The coupling was 1/8" shorter than the original nut. Some 1/2" thread was lost to the shorter length and the coupling bottomed out on the stud, turning it in slightly as the torque wrench clicked. The valve cover stud turned in easily.

I may end up regretting my decision. I will try to give updates occasionally as to it's endurance.

I did find during my adventure that the engine has been worked on before. To what extent, I don't know. I did find two push rods had been replaced and the valves were remarkably at the proper setting of 0.012" on the intake and 0.014" on the exhaust. I need to double check with someone more experienced with the fuel system. The Roosa Master pump inlet fuel intake was clean, but it did not come out in one piece. The seal, plunger and spring stayed in the pump. After draining the fuel from the inlet, it was a couple minutes of fiddling to get the seal unstuck from the threads of the drain. I wasn't sure how durable the seal was and how much tugging it could endure.

@ Tinker: I'm alright with accepting what others have to say about what I do...when it's respectful. I'm not all-knowing and I know it. That's why I come to forums where others have more/different experiences than I.

Now I'm off to start another topic about fuel pump timing...which I most likely should have done before doing the "tune-up". lol
 

Tinkerer

Senior Member
Joined
May 21, 2009
Messages
9,342
Location
The shore of the illinois river USA
Tinker … "What's a "Hard SOG" ?
Son Of a Gun . :)
Anthony ; I am surprised those nuts were hard enough to withstand the torque.
If those nuts were available, any CNH dealer can look in the Case data base and tell you exactly how many of those nuts (or any other part) are in the North American system. And the location of those parts.
 
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