knuckle question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

jay_shy · 02-27-2005, 07:25 PM

Bare with me here on another lift question. I have a 68 K10 and want to know what is involved in switching from a closed knuckle to an open knuckle is. Or if there is another alternative. The reason is I want to lift my truck 4inches and was told I need an open knuckle. Any help would be great.

**JIMs70GMC** · 02-27-2005, 08:09 PM

Unfortunately the only way to go from closed to open is to find a 1970 or newer axle and swap it in. 71 and newer will get you disc brakes. Shouldn't have any problems lifting a closed knuckle truck. The front springs are the same as the 69 and up. Your bigger problem would be the rear as lift springs are not available off the shelf. You could lift it in the rear w/ blocks or shackle flip.

jay_shy · 02-27-2005, 08:50 PM

I will be using blocks in the rear but will I need a drop pitman or a draglink. I am confused here. I was under the impression I need an open knuckle for this reason.

Please help.
Jason

67-72williso · 03-26-2005, 10:29 PM

You can use your original front (closed knuckle). All you need to do is correct your steering geometry.

**kwmech** · 03-26-2005, 10:43 PM

Quote:

Originally Posted by 67-72williso

You can use your original front (closed knuckle). All you need to do is correct your steering geometry.

That is if he gets a dropped pitman arm. You may want to consider the disc front end anyways as stated before.

RainFade · 03-29-2005, 04:16 PM

You don't necessarily NEED a dropped arm for 4" of lift.
Ideally you want the drag link as horizontal as possible but I'll bet you'd be fine with 4"
However lift does often imply bigger meats and stopping that extra mass with drums may be a bit hairy. Heck the disc/drum on my 71 is funky enough under hard braking even unloaded that I'm accumulating parts for rear disc, 4 wheel drum and some big skins may be a quite exhilarating.

1969 GMC · 03-29-2005, 04:24 PM

yeah my truck has 4 whl drums and 32's, and while it was fine for a DD, and carrying smaller loads, it got "fun" when carrying a huge load and a ton of people, or if the brakes got wet

**Yukon Jack** · 03-29-2005, 04:49 PM

When I did my first lift of 4" the steering was much better once corrected. It wasn't a big problem, but great once corrected. My 69 also has the closed knuckle front end and an adustable drag link from Skyjacker or maybe it was Superlift got my steering corrected.

69TowRig · 03-29-2005, 09:37 PM

Some '69s have open knuckles, my Blazer does. Of course you still won't have discs.

Here is an axle from a '72 for sale on Pirate4x4 for $300. I had to pass it up as I had already bought all my disc conversion parts:

http://www.pirate4x4.com/forum/showthread.php?t=339502

Rod · 03-30-2005, 01:09 PM

I think why you got told you needed a newer axle is because someone was thinking you were going with a bigger lift. At 4 inches I think you can use what you have. It is a closed knuckle in 68 so a disc brake swap isn't possible.

What I figure someone was trying to sterr you too was a cross over steering set up used in 8 inch lifts and such.

Good article here on flat top steering knuckles needed for that swap. http://www.pirate4x4.com/tech/billav...ngresearch.htm

Superron21 · 04-10-2005, 08:50 AM

my steering is all stock w/ non adjustable drag link and it steers and stops fine with closed knuckles and all plus, no mud gets into my axle!

ron

02-27-2005, 07:25 PM	#1
jay_shy SWB 4X4 CLUB Join Date: Feb 2005 Location: PA Posts: 1,088	knuckle question Bare with me here on another lift question. I have a 68 K10 and want to know what is involved in switching from a closed knuckle to an open knuckle is. Or if there is another alternative. The reason is I want to lift my truck 4inches and was told I need an open knuckle. Any help would be great.

02-27-2005, 08:09 PM	#2
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	Unfortunately the only way to go from closed to open is to find a 1970 or newer axle and swap it in. 71 and newer will get you disc brakes. Shouldn't have any problems lifting a closed knuckle truck. The front springs are the same as the 69 and up. Your bigger problem would be the rear as lift springs are not available off the shelf. You could lift it in the rear w/ blocks or shackle flip. __________________ 1970 K25, 8' stepside bed 350/465/205 44 up front, 60 in the rear 4.10s rolling on 33" Dunlop MTs 1986 K5, 350/465/208 Dana 60/14 bolt from a cucv 36" Super Swampers TSL/SX 1983 K20 w/ CUCV axles, 350/700R4/208 sitting on 37" Goodyears 1986 M1031 6.2 diesel, TH400/NP205 locker in the rear and a LS in the front, all stock for now..... 1986 K30, 350/400/205 dana 60 and 14 bolt. I kept the drivetrain. Body/bad and chassis are gone. 1981 K30, 350/465/205 dana 60 and dually 14 bolt. Has a G80, and a flat bed. Going to replace the flat bed. 1985 K20, 350/400/208 10 bolt and SF 14 bolt. I wonder where I can find some 1 tons. Hmmmmm

03-26-2005, 10:29 PM	#4
67-72williso Junk/Daily Driver Club Join Date: Feb 2004 Location: Manheim, PA 17545 Posts: 253	open or closed You can use your original front (closed knuckle). All you need to do is correct your steering geometry. __________________ Daily Driver: 1970 C-20 400 sbc,sm-465,Dana 61 one ton SRW rear, 3.07 gears, locker. There are three kinds of people: those who make things happen, those who watch things happen, and those who have no idea what happened!

03-29-2005, 04:16 PM	#6
RainFade Registered User Join Date: Nov 2004 Location: Central Ohio Posts: 215	You don't necessarily NEED a dropped arm for 4" of lift. Ideally you want the drag link as horizontal as possible but I'll bet you'd be fine with 4" However lift does often imply bigger meats and stopping that extra mass with drums may be a bit hairy. Heck the disc/drum on my 71 is funky enough under hard braking even unloaded that I'm accumulating parts for rear disc, 4 wheel drum and some big skins may be a quite exhilarating. __________________ 71 K20 350/350/205, dealer air, 4" lift, Flowtech,Edel 1406 on 2101, procomp HEI,4.10's, 33x12.50x16.5 BFG MT's on slots. 4 wheel disc brakes. My lame K20 page My lame Eaton disc brake page

03-29-2005, 04:24 PM	#7
1969 GMC Registered User Join Date: Feb 2003 Location: The Rubber City Posts: 5,498	yeah my truck has 4 whl drums and 32's, and while it was fine for a DD, and carrying smaller loads, it got "fun" when carrying a huge load and a ton of people, or if the brakes got wet __________________ 1969 GMC K2500 1996 Honda Accord 2007 Kawasaki KLR 650

02-27-2005, 08:50 PM	#3
jay_shy SWB 4X4 CLUB Join Date: Feb 2005 Location: PA Posts: 1,088	I will be using blocks in the rear but will I need a drop pitman or a draglink. I am confused here. I was under the impression I need an open knuckle for this reason. Please help. Jason

03-29-2005, 04:49 PM	#8
Yukon Jack Post Whore Join Date: Feb 2000 Location: Rose Hill, KS, USA Posts: 12,686	When I did my first lift of 4" the steering was much better once corrected. It wasn't a big problem, but great once corrected. My 69 also has the closed knuckle front end and an adustable drag link from Skyjacker or maybe it was Superlift got my steering corrected. __________________ 1970 Blazer with a 400 sbc and 4" lift 1980 Pontiac Trans Am, 455 Oldsmobile 2012 Kawasaki Concours 14

03-29-2005, 09:37 PM	#9
69TowRig Senior Member Join Date: Jan 2005 Location: Raleigh, NC Posts: 894	Some '69s have open knuckles, my Blazer does. Of course you still won't have discs. Here is an axle from a '72 for sale on Pirate4x4 for $300. I had to pass it up as I had already bought all my disc conversion parts: http://www.pirate4x4.com/forum/showthread.php?t=339502

03-30-2005, 01:09 PM	#10
Rod Join Date: Dec 1999 Location: Eastern - Manitoba Canada, Winnipeg Posts: 4,369	I think why you got told you needed a newer axle is because someone was thinking you were going with a bigger lift. At 4 inches I think you can use what you have. It is a closed knuckle in 68 so a disc brake swap isn't possible. What I figure someone was trying to sterr you too was a cross over steering set up used in 8 inch lifts and such. Good article here on flat top steering knuckles needed for that swap. http://www.pirate4x4.com/tech/billav...ngresearch.htm __________________ Senior active founding member. 70 3/4 ton GMC Suburban 4x4 250/4 spd. 71 1/2 ton Suburban Chevy 4x4, 350/350 72 Chev 1 ton tow truck 402BB w/Holmes 440 wrecker on propane 2005 FLSTSCI Harley Springer 85 FXSB Harley Lowrider 72 Triumph 650 Bonneville 5spd "Poor people don't have hobbies" Quote from wife.

04-10-2005, 08:50 AM	#11
Superron21 DONT TRY THIS AT HOME! Join Date: Mar 2005 Location: East Tennessee Posts: 119	'68 GMC burb 6' lift my steering is all stock w/ non adjustable drag link and it steers and stops fine with closed knuckles and all plus, no mud gets into my axle! ron



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