a arm question. 3/4 and 1/2 tons - The 1947 - Present Chevrolet & GMC Truck Message Board Network

cc_bob · 04-15-2007, 10:21 AM

I pulled down my 72 c20 yesterday to go through the front end (new upper and lower control arm bushings, ball joints, etc..) and found one of the bushings on the lower a-arm were worn into the a-arm itself. I have a couple of 1/2 ton 67 parts trucks.
Is the lower a-arms the same?

JimKshortstep4x4 · 04-15-2007, 08:29 PM

The lower "A" arm shafts are the same but the lower ball joints are not. The lower ball joints mount up completely different as the C-10 ball joint presses in and the C-20 bolts in, (or is riveted). It looks like you will need to find an "A" arm for your C 20.

Jim

crazy longhorn · 04-15-2007, 09:59 PM

Quote:

Originally Posted by JimKshortstep4x4

The lower "A" arm shafts are the same but the lower ball joints are not. The lower ball joints mount up completely different as the C-10 ball joint presses in and the C-20 bolts in, (or is riveted). It looks like you will need to find an "A" arm for your C 20.

Jim

Both press, but the 20 series has a larger hole in the arm...

L

Aarons72s · 04-16-2007, 02:27 AM

Just go and find a 73-87 3/4 ton and get the lower a arm off of it. They are the same as 67-72 3/4 ton a arms. And I second the larger hole. I tried to put 3/4 ton ball joint in a 1/2 ton a arm. Big difference in the diameter Hope this helps.

cc_bob · 04-16-2007, 05:32 PM

Quote:

Originally Posted by Aarons72s

Just go and find a 73-87 3/4 ton and get the lower a arm off of it. They are the same as 67-72 3/4 ton a arms.

I thought 73-87 used a rubber bushing, maybe it's just C10s that use the rubber bushing. Or maybe I'm confused (wouldn't be the first time)

I'll checkout the local boneyard to see if I can find one. A 73-87 should be a lot easier to fine.

Thanks again for the help, I REALLY appreciate it.
Bob

Aarons72s · 04-18-2007, 07:17 AM

C10 s made the change to rubber bushings in 73. The 73-87 3/4 tons used the same a-arms and disc brake spindles as the 67-72's.
glad I could help.

04-15-2007, 10:21 AM	#1
cc_bob Registered User Join Date: Jan 2004 Location: Burton, Ohio Posts: 95	a arm question. 3/4 and 1/2 tons I pulled down my 72 c20 yesterday to go through the front end (new upper and lower control arm bushings, ball joints, etc..) and found one of the bushings on the lower a-arm were worn into the a-arm itself. I have a couple of 1/2 ton 67 parts trucks. Is the lower a-arms the same? __________________ 67 C10 396 stepside project 72 C20 402 72 K10 SWB (plow truck) 86 K20

04-15-2007, 08:29 PM	#2
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	Re: a arm question. 3/4 and 1/2 tons The lower "A" arm shafts are the same but the lower ball joints are not. The lower ball joints mount up completely different as the C-10 ball joint presses in and the C-20 bolts in, (or is riveted). It looks like you will need to find an "A" arm for your C 20. Jim __________________ 1971 Shortbox step side 4x4, 350 sbc, 3:07 rear end 1965 Impala SS 400 sbc, Muncie rock crusher 1966 Impala SS 396 bbc, TH 400 1969 El Camino, 350 sbc, TH 350 1971 Snowplow built on a Blazer frame 1972 GMC Short bed, stepside, TH 400, 427 BBC

04-16-2007, 02:27 AM	#4
Aarons72s Registered User Join Date: Apr 2006 Location: oklahoma Posts: 10,670	Re: a arm question. 3/4 and 1/2 tons Just go and find a 73-87 3/4 ton and get the lower a arm off of it. They are the same as 67-72 3/4 ton a arms. And I second the larger hole. I tried to put 3/4 ton ball joint in a 1/2 ton a arm. Big difference in the diameter Hope this helps.

04-18-2007, 07:17 AM	#6
Aarons72s Registered User Join Date: Apr 2006 Location: oklahoma Posts: 10,670	Re: a arm question. 3/4 and 1/2 tons C10 s made the change to rubber bushings in 73. The 73-87 3/4 tons used the same a-arms and disc brake spindles as the 67-72's. glad I could help. Last edited by Aarons72s; 04-18-2007 at 07:17 AM.



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