Author Topic: 76 K20 front drive shaft cv joint replacement  (Read 15545 times)

Offline tbrick22

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76 K20 front drive shaft cv joint replacement
« on: November 13, 2013, 08:15:23 PM »
Hi guys, New to the forum. I am narrowing in on a year long 76 k20 rebuild. I had a terrible knock coming from what I thought was a ujoint. After pulling the shaft I realized it wasn't the ujoint but the cv joint. I got the rebuild kit hoping to save some money but I have no idea how the race, springs, and ball are assembled. Could someone PLEASE HELP walk me through the repair process. Any help would be MUCH appreciated, thanks

Offline Jason S

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Re: 76 K20 front drive shaft cv joint replacement
« Reply #1 on: November 13, 2013, 09:57:36 PM »
Have you looked at the Service Manual? There will be procedures on disassembly and reassembling the CV joint in the manual.

http://forum.73-87chevytrucks.com/smforum/index.php?topic=25639.0

1973 GMC K2500, Super Custom, Camper Special, 350, TH350, NP203, 4.10's
1974 Chevrolet K10, Custom Deluxe, 350, SM465, NP203, 3.73's

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Offline rich weyand

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Re: 76 K20 front drive shaft cv joint replacement
« Reply #2 on: November 13, 2013, 10:50:14 PM »
Basically, you start by taking off the wheels and you keep disassembling until you get to the CVJs.  It's sections 3C27/28/29 and 4C2/3 in the 1978 Service Manual, and I think it's about the same for 1976.
Rich

"Working Girl": 1978 K-10 RCSB 350/TH350/NP203 +2/+3 Tuff Country lift

Offline Irish_Alley

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Re: 76 K20 front drive shaft cv joint replacement
« Reply #3 on: November 13, 2013, 11:12:54 PM »
are you talking about the wheel u joints or the  double cardan joint in the driveshaft?
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Offline rich weyand

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Re: 76 K20 front drive shaft cv joint replacement
« Reply #4 on: November 14, 2013, 02:09:55 AM »
My parts book for 1978 only shows front u-joints on the half axles.  No double-cardan joints shown for any of the front axles in 1978.

Which front differential do you have, tbrick22?
Rich

"Working Girl": 1978 K-10 RCSB 350/TH350/NP203 +2/+3 Tuff Country lift

Offline Irish_Alley

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Re: 76 K20 front drive shaft cv joint replacement
« Reply #5 on: November 14, 2013, 04:04:06 AM »
the cardan joint is in the front drive shaft. thats why your book isnt showing it in the half axles ;). found this a couple years ago it was for ford but its all spicer so its the same part number and same steps. the web site i took this from is no longer working so i cant give you a direct link.

But being the cheapskate that I am, and having several cleaned and recycled u-joints from various other driveshaft projects over the past couple of years, I decided to see what my friend, Greg King, manager of King Auto Parts NAPA, might have to replace the worn out CV ball joint. NAPA carries the whole CV ball joint, but they also have a simple rebuild kit (part # 612-NUJ) consisting of the ball and collar, new spring, and the gasket ring for less than $30. Since my CV ball joint was not broken and the four fine threaded holes were in excellent condition, I opted for the NAPA CV rebuild kit. Although it came with no instructions, I was able to finally figure out that the old collar from around the ball had to be removed from my old CV head. After trial-and-error, I finally came upon a very thin, flat screwdriver blade that could chip away at the softer metal of the old ball’s collar. A Dremel-type tool with a cut off wheel would probably have worked better, sigh! Once the old collar was out, I took some fine sand paper and polished any of the screwdriver blade marks that might have slipped, doh! The whole unit was thoroughly cleaned using brake cleaner, wiped down with a clean towel/rag, and allowed to air dry. The new ball and collar was a snug fit, but I located just the right sized socket to fit over the ball and make good contact with the collar. Carefully taping on the socket with a rubber mallet, I constantly rotated the unit so that the new collar eased down into the CV head without getting cocked to one side or the other. The new gasket ring then fit on to the CV head without difficulty, using the same socket-n-mallet technique as the collar and ball. I’ve found it best to leave the red plastic spacer inside the ball until you are ready to install the CV joint as that keeps the small roller bearings in place. Then, when you are ready, pack the ball with grease to ensure that the roller bearings will remain put while you put everything back together.

Whether you remove the second u-joint of the double-cardan joint or not, be certain to closely examine the tip end of the driveshaft.
 
What you are looking at is the hollow tip that the CV ball joint’s ball rotates upon. If the ball is completely worn out, the hollow tip could be deformed, elongated, or oblonged. If you discover that your driveshaft tip is in poor condition, you will want to consider having it replaced by a competent machine shop. The machine shop can precisely and truly remove the tip end assembly and replace it accurately.

One of the most difficult parts of this rebuild was getting the last u-joint installed while keeping the CV ball joint in place. Since the CV ball unit was replaced with a freshly rebuilt unit, the CV ball joint was very tight and significant (hand) pressure was needed to get the bare u-joint into place. Once the double-cardan joint is correctly aligned, replace one of the u-joint caps, taking care not to allow the roller bearings to fall down into the cap. I found that packing the cap with grease and using extreme care to center the u-joint end into the cap was successful. If the cap will not go a sufficient distance into the hole so that the external snap ring can seat fully into the groove, then perhaps one or more of the roller bearings has fallen into the cap. Remove, inspect, rebuild, refill with grease and try again. Since my driveshaft rebuild included replacing all three u-joints, the chances that I would mess up one or more of the caps was high. I messed up only once and that was on the last u-joint, the one holding the CV ball joint in place.
« Last Edit: November 14, 2013, 04:13:30 AM by Irish_Alley »
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Offline tbrick22

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Re: 76 K20 front drive shaft cv joint replacement
« Reply #6 on: November 14, 2013, 06:27:52 AM »
Thanks all for the responses!! Irish_Alley you nailed it THANKS.  This article will get me much closer than I was yesterday.  I am still not real comfortable with how it goes together but this is a good start and suppose I can learn by trial and error.

Offline rich weyand

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Re: 76 K20 front drive shaft cv joint replacement
« Reply #7 on: November 14, 2013, 09:57:44 AM »
the cardan joint is in the front drive shaft. thats why your book isnt showing it in the half axles ;).

Ah.  I have had several front-drive cars with CV joints in the axles, so I assumed he meant the u-joints on the axles. 

The procedure is detailed in section 4A of the 1978 service manual.  GM calls it the propeller shaft, or propshaft.
Rich

"Working Girl": 1978 K-10 RCSB 350/TH350/NP203 +2/+3 Tuff Country lift

Offline Irish_Alley

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Re: 76 K20 front drive shaft cv joint replacement
« Reply #8 on: November 14, 2013, 10:58:16 PM »
its one of those things you dont really think about till you need to rebuild it. was at autozone just bsing with the managers. this guy brings in this front driveshaft. i didnt have my smartphone on me but the manager was trying to sell the whole joint, i told him he didnt have to replace it all just needed to rebuild it but for the life of me i couldnt remember the name of it.
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Offline rdfmartin

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Re: 76 K20 front drive shaft cv joint replacement
« Reply #9 on: June 08, 2015, 11:59:29 AM »
the cardan joint is in the front drive shaft. thats why your book isnt showing it in the half axles ;). found this a couple years ago it was for ford but its all spicer so its the same part number and same steps. the web site i took this from is no longer working so i cant give you a direct link.

But being the cheapskate that I am, and having several cleaned and recycled u-joints from various other driveshaft projects over the past couple of years, I decided to see what my friend, Greg King, manager of King Auto Parts NAPA, might have to replace the worn out CV ball joint. NAPA carries the whole CV ball joint, but they also have a simple rebuild kit (part # 612-NUJ) consisting of the ball and collar, new spring, and the gasket ring for less than $30. Since my CV ball joint was not broken and the four fine threaded holes were in excellent condition, I opted for the NAPA CV rebuild kit. Although it came with no instructions, I was able to finally figure out that the old collar from around the ball had to be removed from my old CV head. After trial-and-error, I finally came upon a very thin, flat screwdriver blade that could chip away at the softer metal of the old ball’s collar. A Dremel-type tool with a cut off wheel would probably have worked better, sigh! Once the old collar was out, I took some fine sand paper and polished any of the screwdriver blade marks that might have slipped, doh! The whole unit was thoroughly cleaned using brake cleaner, wiped down with a clean towel/rag, and allowed to air dry. The new ball and collar was a snug fit, but I located just the right sized socket to fit over the ball and make good contact with the collar. Carefully taping on the socket with a rubber mallet, I constantly rotated the unit so that the new collar eased down into the CV head without getting cocked to one side or the other. The new gasket ring then fit on to the CV head without difficulty, using the same socket-n-mallet technique as the collar and ball. I’ve found it best to leave the red plastic spacer inside the ball until you are ready to install the CV joint as that keeps the small roller bearings in place. Then, when you are ready, pack the ball with grease to ensure that the roller bearings will remain put while you put everything back together.

Whether you remove the second u-joint of the double-cardan joint or not, be certain to closely examine the tip end of the driveshaft.
 
What you are looking at is the hollow tip that the CV ball joint’s ball rotates upon. If the ball is completely worn out, the hollow tip could be deformed, elongated, or oblonged. If you discover that your driveshaft tip is in poor condition, you will want to consider having it replaced by a competent machine shop. The machine shop can precisely and truly remove the tip end assembly and replace it accurately.

One of the most difficult parts of this rebuild was getting the last u-joint installed while keeping the CV ball joint in place. Since the CV ball unit was replaced with a freshly rebuilt unit, the CV ball joint was very tight and significant (hand) pressure was needed to get the bare u-joint into place. Once the double-cardan joint is correctly aligned, replace one of the u-joint caps, taking care not to allow the roller bearings to fall down into the cap. I found that packing the cap with grease and using extreme care to center the u-joint end into the cap was successful. If the cap will not go a sufficient distance into the hole so that the external snap ring can seat fully into the groove, then perhaps one or more of the roller bearings has fallen into the cap. Remove, inspect, rebuild, refill with grease and try again. Since my driveshaft rebuild included replacing all three u-joints, the chances that I would mess up one or more of the caps was high. I messed up only once and that was on the last u-joint, the one holding the CV ball joint in place.
I realize that this is an old thread, but I am having a problem similar to this post. I got a replacement cv joint that only requires removing and replacing one u-joint, but I can't quite get the u-joint in. All the other u-joints went in easily, but the ball-socket setup prevents me from installing the u-joint to the cv joint. The ball-socket combo snapped into place. It is really close to going in, but I can't quite get the new u-joint in straight. Thought I'd ask for info before I do something that causes more problems. Not sure if I did something wrong, or if I need to use more force. Anyone familiar with this installation? It is on an 86 Chevy K10 with a New Process 208c transfer case.
« Last Edit: June 08, 2015, 12:02:17 PM by rdfmartin »

Offline Irish_Alley

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Re: 76 K20 front drive shaft cv joint replacement
« Reply #10 on: June 09, 2015, 01:25:09 PM »
ill tell you the truth its been years since ive done one so i forget the details i know it was a pain to do.
check this out its the section 4a that rich was talking about
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Offline enaberif

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Re: 76 K20 front drive shaft cv joint replacement
« Reply #11 on: June 09, 2015, 02:05:18 PM »
I realize that this is an old thread, but I am having a problem similar to this post. I got a replacement cv joint that only requires removing and replacing one u-joint, but I can't quite get the u-joint in. All the other u-joints went in easily, but the ball-socket setup prevents me from installing the u-joint to the cv joint. The ball-socket combo snapped into place. It is really close to going in, but I can't quite get the new u-joint in straight. Thought I'd ask for info before I do something that causes more problems. Not sure if I did something wrong, or if I need to use more force. Anyone familiar with this installation? It is on an 86 Chevy K10 with a New Process 208c transfer case.

I'm really trying to make sense of this but unfortunately I can't sorry.

Offline Blazin

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Re: 76 K20 front drive shaft cv joint replacement
« Reply #12 on: July 15, 2015, 05:48:23 AM »
Have done a bunch over the years. The last couple I have done, I took the whole shaft to a drive shaft shop. Its was money well spent to not have to hassle with it.
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