Drive shaft and 1/2 shaft u-joint replacement

[Jeff C.]

Merry Xmas All!
I am installing a rebuilt differential in my 1963 so all of the drive/axle shafts are out. Normally I would replace any parts subject to wear when they are out of the car. However, even though I have removed and installed u-joints in the past I am concerned that the chance of damage to the shafts when replacing 6 u-joints makes me hesitate in this case. All 6 seem to be in good shape with no binding of the bearings. Does anyone have a thought on this?
Thanks

[Duke W.]

Re: Drive shaft and 1/2 shaft u-joint replacement

How many miles do you drive per year? Do you drive a lot in the rain?

If the u-joints are okay now, they will probably last a long time. Also, if you have the original '63 cast iron half-shaft flanges, they are easy to distort when changing the u-joints... much more so that the later forged flanges.

You should also check for u-joint grounding at full rebound before you put the car back down on the ground... '63s are particularly suseptable to u-joint grounding. If they do, I recommend you replace the cast iron flanges with the later forged design, which offer more clearance even though it's a judging deduction.

Duke

[Ed S.]

Re: Drive shaft and 1/2 shaft u-joint replacement

Jeff,

I agree with Duke. FYI - I replaced 6 U joints in my 64 recently. The ones on my car were not originals and I know they were replaced more than 12 years ago but the car was not driven in wet weather much. They came out relatively easy - mild tapping and a bit of penetrating lubricant - no damage to flanges. Point is, if yours were once replaced, if you decide to put new ones in the old ones may come out easier than you think. But.... if they are in good condition and are old enough to be NOS replacements you might just keep them. Very difficult to find "original" U joints - NOS, if you can find them cost a fortune. Also - Federal Mogul, MOOG replacements sold now do not fit - there have been a few threads in this subject recently on this forum that describe very tight fits. I installed Spicer brand U joints after I discarded a new set of Federal Moguls (made in Mexico) that did not fit - they are too wide - could not get the retainer clip in. Hope this helps in your decision.

[Richard G.]

Re: Drive shaft and 1/2 shaft u-joint replacement

U-joint replacement is a job that most people use a hammer for. The hammer method almost always this results in some type of mechanical damage. Either to the drive shaft tube in the form of indentations or bending of the ears on one of both of the flanges. For this reason it is almost impossible to purchase good used parts as in my experience 95% of them are bent. Many automotive shops also bend the flanges, for this reason I recommend a specialized drive-shaft shop if one has to farm this job out. Just putting the shaft into a vise typically results in damage to the tube. If the tube isn't crushed when the operator tightens the jaws it is damaged when the mechanic gets out his four pound hammer and starts beating on the flange to remove the joint. It absolutely can be done at home with some care. GM makes a tool designed to be used in a press but a hammer will work in conjunction with this tool. Or make something like it at home if you can. It pushes on the cross and removes one trunion bearing at a time. This tool has been available for at least 70 years. It is designed to keep from bending flanges, it is the only reason it exists.

Typically the most inexpensive source for this tool is Ebay. Search "Kent Moore J-9522-3".

The best video out there for joint replacement is this one:

https://www.youtube.com/watch?v=U6QKs9JajQ4

It is done by WeberAuto a trade school. The narrator is good and covers everything in detail without repetition.

Also watch;
Universal Joints - Part 7: Centering and Adjusting Axial Play

https://www.youtube.com/watch?v=10BhHuwnQ7I

The video explains the reason some of the joints come with an assortment of variable thickness snap rings.
The OEM joints included the extra snap rings and also cost $70 and more.
The cheap joints only come with one set of snap rings and the radial play is not adjustable.

Our cars are expensive and a u-joint failure is serious business because the joints also hold the wheels in vertical alignment.
For this reason when they fail the results can be a wreck or the loss of the rear fender.
This was the compromise in the original independent suspension design.
It had to be inexpensive enough for Chevrolet to built and make a profit or it wouldn't have gotten past the bean counters.
Just remember the drive shaft is both a drive component and a suspension component.
I do not know of any modern independent suspensions that are built this way.
All the new stuff has the drive shaft only driving the wheels as safety takes a higher priority than it did in the 60's.
Best of luck
Rick

[Bob W.]

Re: Drive shaft and 1/2 shaft u-joint replacement

Rick Great video nice tool thanks for the info.

[Al R.]

Re: Drive shaft and 1/2 shaft u-joint replacement

I have always used a press with a large enough socket to fit on the flange of the driveshaft and still allow the cup of the u-joint to slide inside when pressing it out. To press it from the opposite side I use a socket approx. the same size as the outer OD of the cup or either a short piece of round stock. This requires having a helper to hold the driveshaft while you do the pressing. My press is a hand type jack style (not a foot controlled), so I can control it better. Hope this helps. Al

[Gary R.]

Re: Drive shaft and 1/2 shaft u-joint replacement

I never press them apart, I bolt on my steel plate, put them in a Rigid Tripod, and burn them out. I use the blue wrench and cut out the cross, the heat transfers to the caps to break the rust loose. I never damaged the yokes or flanges this way. I clean the bores with wire wheel just enough to polish them- not to enlarge them. I lube the caps with WD40 and place the new cross in place, line up one cap and slowly tap it in place- flush to the yoke face. I hold the cross into the cap while doing this so the needles don't come out. I put a smear of grease on the needles to hold them in as well. Flip it over and tap in the other cap, with both flush I slightly press in one cap, install the copper clip from the Spicer kit, flip over final press the other cap, install the other copper clip, place in between (2) 2x4's and give it a wack with a big hammer, that sets the caps and clips, causing no damage, and the joint is free and smooth.

[Richard G.]

Re: Drive shaft and 1/2 shaft u-joint replacement

Al;
Let me start with I have done hundreds of joints using your method (Pressing on the top cap). However after making a mandrel to check the flange ear's alignment I changed my ways. The "press on the top cap" method puts strain on the top (unsupported) cap that is transferred to the flange ear. If the cup does not come out easily the top ear will be bent down. Thus the reason for the tool that presses only on the cross. It is designed to only load the bottom ear which is supported by the socket, in your case. During re-assemble a bent ear will manifests itself in two ways. A difficult to rotate cross and/or the inability to insert the snap ring properly into the groove. I have taken my mandrel to swap meets and literally checked 25 flanges in a day. Only two passed the mandrels between ears. I just assume the ears are bent on used parts and I am not usually disappointed. I like Gary's method also. It does require a torch and a shop where flying sparks are not an issue. But I believe it keeps the ears collinear which should be your goal. If you have a chronic u-joint longevity issue it can typically be traced to bent parts. I spent the last 20 years of my working career working in precision maintenance and completing root cause analysis.
Rick

[Michael L.]

Re: Drive shaft and 1/2 shaft u-joint replacement

I realize a big reason why we do this is the thrill of getting our hands dirty and fixing stuff ourselves. However, I must say that IMHO for the vast majority of guys this is best left to a professional driveshaft shop, if you decide to change them. During the resto of my 69 I tried doing the first change myself and the u-joints came out easy I thought, but I couldn't get the very first one back in, so I decided to bring them to a professional shop. They determined that the ears were bent on the one I was working on (the rest were fine). They cut the old one off, welded on a new flange, checked the balance of all the shafts, and installed the u-joints and tranny yoke on all three (I supplied them all) for a very reasonable cost, something like $150. Really very reasonable and given the potential for serious catastrophe if it fails I felt it wasn't worth risking it.

[Jim D.]

Re: Drive shaft and 1/2 shaft u-joint replacement

I do what Gary above does. Burn them out. Never had an issue doing it that way.

[Jeff C.]

Re: Drive shaft and 1/2 shaft u-joint replacement

Thanks everyone,
the u-joint was binding on the one flange because it was already bent. I'm getting a new flange and looking into shop installation.

[David M.]

Re: Drive shaft and 1/2 shaft u-joint replacement

U-joint replacement is a job that most people use a hammer for. The hammer method almost always this results in some type of mechanical damage. Either to the drive shaft tube in the form of indentations or bending of the ears on one of both of the flanges. For this reason it is almost impossible to purchase good used parts as in my experience 95% of them are bent. Many automotive shops also bend the flanges, for this reason I recommend a specialized drive-shaft shop if one has to farm this job out. Just putting the shaft into a vise typically results in damage to the tube. If the tube isn't crushed when the operator tightens the jaws it is damaged when the mechanic gets out his four pound hammer and starts beating on the flange to remove the joint. It absolutely can be done at home with some care. GM makes a tool designed to be used in a press but a hammer will work in conjunction with this tool. Or make something like it at home if you can. It pushes on the cross and removes one trunion bearing at a time. This tool has been available for at least 70 years. It is designed to keep from bending flanges, it is the only reason it exists.

Typically the most inexpensive source for this tool is Ebay. Search "Kent Moore J-9522-3".

The best video out there for joint replacement is this one:

https://www.youtube.com/watch?v=U6QKs9JajQ4

It is done by WeberAuto a trade school. The narrator is good and covers everything in detail without repetition.

Also watch;
Universal Joints - Part 7: Centering and Adjusting Axial Play

https://www.youtube.com/watch?v=10BhHuwnQ7I

The video explains the reason some of the joints come with an assortment of variable thickness snap rings.
The OEM joints included the extra snap rings and also cost $70 and more.
The cheap joints only come with one set of snap rings and the radial play is not adjustable.

Our cars are expensive and a u-joint failure is serious business because the joints also hold the wheels in vertical alignment.
For this reason when they fail the results can be a wreck or the loss of the rear fender.
This was the compromise in the original independent suspension design.
It had to be inexpensive enough for Chevrolet to built and make a profit or it wouldn't have gotten past the bean counters.
Just remember the drive shaft is both a drive component and a suspension component.
I do not know of any modern independent suspensions that are built this way.
All the new stuff has the drive shaft only driving the wheels as safety takes a higher priority than it did in the 60's.
Best of luck
Rick

Awesome advice here to look for a drive shaft shop. Fleet Pride is a chain that specializes in driveshafts. Any large truck shop should have this service just ask around to insure the shops reputable and knows cars and not just large commercial drive-lines.
Denny's out of Buffalo is superior as well. http://www.dennysdriveshaft.com/
If it hasn't been mentioned yet Im a firm advocate/believer of Spicer brand U-Joints. Superior USA made quality, period. As stated its a safety thing to have the highest quality joints on all 3 shafts (No offshore junk allowed!). Have said shop install Spicer joints and re-balance the shafts. Some will paint per request or leave it natural.
The attached pic is of the main shaft I recently had done (Cook Brothers in Rochester NY). Same shop surfaced the flywheel and supplied new U Straps as well(cheap safety item here!).

[Gary R.]

Re: Drive shaft and 1/2 shaft u-joint replacement

I agree on using Spicer solid joints but the cross bodies are larger so you will have to slightly radius the yokes to get them in place. They fit new flanges but not the old ones without the mod.

[Scott O.]

Re: Drive shaft and 1/2 shaft u-joint replacement

Gary,
Can you post a picture of the slight radius added.
Thank you, Scott

[Gary R.]

Re: Drive shaft and 1/2 shaft u-joint replacement

Scott
Here is a link to an older thread on joints. There is one picture with a larger radius then typically needed but I wanted to show where it was so I opened up a flange more then needed. All you need to do, if yours does not fit, is slightly radius the top inside of the yoke, a little at a time till the cross fits. New flanges should not require a radius. If your flange is bent you are not going to get the c-clip in place. The copper clips that come with the solid spicers should snap in place on both sides. Once seated the axial play will be about 001-002"

http://www.digitalcorvettes.com/forums/showthread.php?t=76752