I Hate Asking Stupid Questions......But - The 1947 - Present Chevrolet & GMC Truck Message Board Network

blown240 · 03-10-2016, 08:02 PM

I hate to ask stupid questions, but I've searched and can't find the answer.

I put power steering in my 61. The new pitman arm doesn't have a hole for the cotter pin, so I want to put a nylock on it, as I found when I searched.

The problem is that I don't know what size it is. I read 7/8-14, but thats HUGE compared to this.

Does anyone know the size of this nut, or should I just put some red or blue loctite and torque down the castle nut?

Thanks!

**The Rocknrod** · 03-10-2016, 08:08 PM

Do you mean the shaft on the steering gear box?

blown240 · 03-10-2016, 08:10 PM

I mean pitman arm to center link.

61_FL_Apache · 03-10-2016, 08:25 PM

Quote:

Originally Posted by blown240

I mean pitman arm to center link.

It should have had a hole in it. The one on the box does not.

Things that make you go... hmmmm...

blown240 · 03-10-2016, 08:27 PM

Ya I was surprised it didn't have a hole. It's off of an 81 c30.

**61ChevyPanel** · 03-10-2016, 09:33 PM

I sold fasteners for years. The size of the wrench used on a fastener isn't measured since there are many head types. A 1/2" bolt will measure 1/2" in diameter. Measure the diameter of the pitman arm threads, an end wrench works well. If it measures 7/8", then it's a 7/8" nut. The hole in a 7/8" nut won't be 7/8", it will be smaller.

Once you determine the diameter of a bolt or nut, you must determine the number of threads per inch. Non-metric fasteners are most commonly either coarse thread or fine thread but there is extra fine thread such as what's used on carb linkages. A 7/8" coarse thread has 9 threads per inch and a fine thread has 14 threads per inch. Thread charts can be found online. You could use a thread gauge, or count the threads per inch or if you have any spare 7/16" bolts, a 7/16" coarse thread bolt has 14 threads per inch. A 7/16" - 14 bolt coarse threads will line up perfectly with a 7/8" fine thread because they both have 14 threads per inch.

Bolts are specified by the diameter, threads per inch, then length. The length is measured under the head, except for flat head screws which are measured in overall length. For example a 3/8" - 16 x 1" is 3/8" in diameter with 16 threads per inch and one inch long under the head.

Big Fenders · 03-10-2016, 09:56 PM

I think pitman arms are hardened so drilling for a pin would be difficult..If you can find a nylock nut that size it's what I'd do and check every so often.
No questions are stupid

blown240 · 03-10-2016, 10:55 PM

Thanks for the replies guys!

61ChevyPanel - What your saying makes sense, so I went out and checked the threads with a wrench. 9/16 won't go over them, and 5/8 has play. That makes me lean towards 16mm, but I know that can't be the case, because its the same size that the 61 had originally.

Ill go to a good fastener store and look at 9/16 and 5/8 fine thread. Ill take the castle nut I have and try to find a nylock.

**61ChevyPanel** · 03-11-2016, 01:06 AM

A 5/8" wrench will have a little play on the threads of a 5/8" bolt. On a bolt that doesn't have threads all the way up, the unthreaded part will be 5/8" but the diameter where the threads are is a little smaller. A 9/16" - 18 nut usually takes a 7/8" wrench. A 5/8" - 18 nut usually takes a 15/16" wrench but there are exceptions...

blown240 · 03-11-2016, 01:38 AM

Great! It takes a 15/16 wrench I believe. I'll try to get to the hardware store tomorrow! Thanks!

frankslagoon · 03-11-2016, 01:29 PM

I just put a gear box from a 82 on my trk. the new steering gears don't have a cotter key. The nut is a jam nut. as soon as ya start it on the pittman arm it will get hard to turn and continue to show resistains till it comes up tight. If you have the nut that came with the gear you will be fine. If it's good enough for GM it's good enough.

blown240 · 03-11-2016, 01:44 PM

Thanks Frank.

Unfortunately I don't have the nut that came with it.

61K10 · 03-11-2016, 02:27 PM

go to ACE hardware, they have lock nuts similar to a nylock.

frankslagoon · 03-11-2016, 07:00 PM

Quote:

Originally Posted by blown240

Thanks Frank.

Unfortunately I don't have the nut that came with it.

Well that's what I figured. to bad. might be worth goingto GM and buyin one. or try and get one at the wreckin yard.

padresag · 03-11-2016, 08:10 PM

Quote:

Originally Posted by frankslagoon

Well that's what I figured. to bad. might be worth goingto GM and buyin one. or try and get one at the wreckin yard.

get a new one. they are only meant for one application
ron

03-10-2016, 08:02 PM	#1
blown240 Registered User Join Date: Jan 2011 Location: CA Posts: 772	I Hate Asking Stupid Questions......But I hate to ask stupid questions, but I've searched and can't find the answer. I put power steering in my 61. The new pitman arm doesn't have a hole for the cotter pin, so I want to put a nylock on it, as I found when I searched. The problem is that I don't know what size it is. I read 7/8-14, but thats HUGE compared to this. Does anyone know the size of this nut, or should I just put some red or blue loctite and torque down the castle nut? Thanks! __________________ '61 Panel - Helms Bakery Truck - Daily Driver - FOR SALE

03-10-2016, 08:08 PM	#2
The Rocknrod Moderator Join Date: Aug 2011 Location: China Spring, TX Posts: 7,280	Re: I Hate Asking Stupid Questions......But Do you mean the shaft on the steering gear box? __________________ Master Chief, US Navy, Retired 1964 C10 Step-side Short Bed - In Progress 2009 2500HD Duramax LTZ 1948 GMC Panel 1956 Big Window Stepside 1953 5 Window Chevy Stepside 1932 Coupe New Seat Foam for Bench Seats?

03-10-2016, 08:10 PM	#3
blown240 Registered User Join Date: Jan 2011 Location: CA Posts: 772	Re: I Hate Asking Stupid Questions......But I mean pitman arm to center link. __________________ '61 Panel - Helms Bakery Truck - Daily Driver - FOR SALE

03-10-2016, 08:27 PM	#5
blown240 Registered User Join Date: Jan 2011 Location: CA Posts: 772	Re: I Hate Asking Stupid Questions......But Ya I was surprised it didn't have a hole. It's off of an 81 c30. __________________ '61 Panel - Helms Bakery Truck - Daily Driver - FOR SALE

03-10-2016, 09:33 PM	#6
61ChevyPanel Active Member Join Date: Nov 2011 Location: Los Angeles, CA Posts: 113	Re: I Hate Asking Stupid Questions......But I sold fasteners for years. The size of the wrench used on a fastener isn't measured since there are many head types. A 1/2" bolt will measure 1/2" in diameter. Measure the diameter of the pitman arm threads, an end wrench works well. If it measures 7/8", then it's a 7/8" nut. The hole in a 7/8" nut won't be 7/8", it will be smaller. Once you determine the diameter of a bolt or nut, you must determine the number of threads per inch. Non-metric fasteners are most commonly either coarse thread or fine thread but there is extra fine thread such as what's used on carb linkages. A 7/8" coarse thread has 9 threads per inch and a fine thread has 14 threads per inch. Thread charts can be found online. You could use a thread gauge, or count the threads per inch or if you have any spare 7/16" bolts, a 7/16" coarse thread bolt has 14 threads per inch. A 7/16" - 14 bolt coarse threads will line up perfectly with a 7/8" fine thread because they both have 14 threads per inch. Bolts are specified by the diameter, threads per inch, then length. The length is measured under the head, except for flat head screws which are measured in overall length. For example a 3/8" - 16 x 1" is 3/8" in diameter with 16 threads per inch and one inch long under the head.

03-10-2016, 09:56 PM	#7
Big Fenders Registered User Join Date: Mar 2008 Location: Tucson Arizona Posts: 264	Re: I Hate Asking Stupid Questions......But I think pitman arms are hardened so drilling for a pin would be difficult..If you can find a nylock nut that size it's what I'd do and check every so often. No questions are stupid

03-10-2016, 10:55 PM	#8
blown240 Registered User Join Date: Jan 2011 Location: CA Posts: 772	Re: I Hate Asking Stupid Questions......But Thanks for the replies guys! 61ChevyPanel - What your saying makes sense, so I went out and checked the threads with a wrench. 9/16 won't go over them, and 5/8 has play. That makes me lean towards 16mm, but I know that can't be the case, because its the same size that the 61 had originally. Ill go to a good fastener store and look at 9/16 and 5/8 fine thread. Ill take the castle nut I have and try to find a nylock. __________________ '61 Panel - Helms Bakery Truck - Daily Driver - FOR SALE

03-11-2016, 01:06 AM	#9
61ChevyPanel Active Member Join Date: Nov 2011 Location: Los Angeles, CA Posts: 113	Re: I Hate Asking Stupid Questions......But A 5/8" wrench will have a little play on the threads of a 5/8" bolt. On a bolt that doesn't have threads all the way up, the unthreaded part will be 5/8" but the diameter where the threads are is a little smaller. A 9/16" - 18 nut usually takes a 7/8" wrench. A 5/8" - 18 nut usually takes a 15/16" wrench but there are exceptions...

03-11-2016, 01:38 AM	#10
blown240 Registered User Join Date: Jan 2011 Location: CA Posts: 772	Re: I Hate Asking Stupid Questions......But Great! It takes a 15/16 wrench I believe. I'll try to get to the hardware store tomorrow! Thanks! __________________ '61 Panel - Helms Bakery Truck - Daily Driver - FOR SALE

03-11-2016, 01:29 PM	#11
frankslagoon Registered User Join Date: Jan 2014 Location: Wasilla Alaska Posts: 537	Re: I Hate Asking Stupid Questions......But I just put a gear box from a 82 on my trk. the new steering gears don't have a cotter key. The nut is a jam nut. as soon as ya start it on the pittman arm it will get hard to turn and continue to show resistains till it comes up tight. If you have the nut that came with the gear you will be fine. If it's good enough for GM it's good enough.

03-11-2016, 01:44 PM	#12
blown240 Registered User Join Date: Jan 2011 Location: CA Posts: 772	Re: I Hate Asking Stupid Questions......But Thanks Frank. Unfortunately I don't have the nut that came with it. __________________ '61 Panel - Helms Bakery Truck - Daily Driver - FOR SALE

03-11-2016, 02:27 PM	#13
61K10 Registered User Join Date: Feb 2012 Location: pleasant valley--placerville ca Posts: 3,039	Re: I Hate Asking Stupid Questions......But go to ACE hardware, they have lock nuts similar to a nylock. __________________ 1961 chevy K10 my build is------------61K10 build

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