Mopar Boy
Enthusiast
As our cars get older, and the already stressed U joints on the half shafts continue to get worn, this info may become useful. Although I am showing how to do a half shaft, this will be the same process for a driveshaft.
For those that do not know, the half shafts on our cars have a universal joint (U joint) on each end of the shaft. This allows the differential to provide power by way of the half shaft to the tires. As the suspension moves up and down, plus with the angle that the shaft comes out of the diff, it needs a joint on each end to allow enough movement so the shaft does not bind. This joint is the U joint. With enough hard launches, plus normal wear from vehicle mileage and age (age matters at the grease in the Vipers non grease-able joints will eventually dry up), the U joints will start to need attention. How do you know if your U joint is getting there? There is a few different ways ranging from reaching higher mileage to it letting go during a hard launch.
For me, I had a half shaft break a few years ago while at a drag strip (not the U joint, I actually broke the shaft due to old tires and axle hop). I replaced with one that was purchased used from another VCA member and just installed it. Over the cource of the last few years, the abuse and wear has started to wear the already higher mileage half shaft to the point that I could hear squeaking, clicking, and a faint grinding that did not “feel” right. I mostly noticed this at slow speeds when the window was open.
So I decided to pull it out, and upon removing the straps, the caps fell to the floor! This is a good sign that it is time to replace the U joints!
U joint replacement is very easy. The key will be to have a mechanical press to be able to push the joints out slowly without damaging anything.
Here is an comparison of new and original:
U joint part number and box:
First step is to remove the half shaft from the vehicle. Once removed, you must remove the retaining clips.
Using the press, apply slight pressure to one side of the joint. I used a small length of steel for this that had a smaller diameter than the eye. Once you can see the joint shift, using needle nose pliers and pop the retainer out. Flip half shaft over and do the same to the other side. Once the clip is removed, continue pushing the cap with the steel cylinder. (HINT: You will need to have the bottom side supported all the way around the half shaft ear so it does not break off. If it is not supported it could crack. I found a socket works well so it can still allow the cap space to drop out the bottom.)
Continue pushing until the cap post out the bottom or the U joint bottoms out. Remove cap, flip half shaft over, and again push down on the cap until it pops out.
You can then remove the U joint from the two eyes. You can inspect the old caps for signs of wear. The needle bearings should be clean and in one piece. If you see debris, your bearing needles were fryin’.
Old on left, new on right:
Close up of new (observe the good needle bearings in the caps):
Repeat for other side.
Once both joints are removed, clean up the half shaft. Ensure that it is clean with no dirt on either end, especially around the eyes.
Using a new U joint, remove two of the caps. Ensuring not to nick or scrape the surface of the now exposed bearing needle surface, slide it into the two eyes. Doing the exact opposite as before, slide a cap onto one of the end and press it back into the eye until in approx seating position. Next, push the cap into the other end.
When at the seating point on both sides, press one side just a bit further and install the retaining clip. Then press it back the opposite direction to install the other side. Then try to even the pressure out so it is not loaded on one side more than the other.
Repeat the other side.
The finished shaft will look like this:
For installing into the car, again be very cautious not to knock the caps off. I found it easiest to remove the two other caps when putting the half shaft back thought the shock support. If you also do this be very sure to not get ANY dirt or even bumping the exposed ends! If you do, may as well pull it back out and replace the U joint now.
Once back in, re-strap the joints to the hubs and diff with NEW straps and you are done! Why new straps? The U joint straps are slightly straighter than the arc they need to be. This way when it is torque, it shapes itself to the joint cap. If you use the same strap, when you finish torquing the strap, it may be fully tight by way of the bolts, but the cap could have a different tolerance than the last and it would then not provide adequate clamping force for the joint. You would essentially have a loose cap. The result? First hard shift or clutch drop and you just ripped your U joint out.
That’s it! Repeat for the other side of the car and be sure to mark the mileage in your maintenance book!
Have fun!
Robert
For those that do not know, the half shafts on our cars have a universal joint (U joint) on each end of the shaft. This allows the differential to provide power by way of the half shaft to the tires. As the suspension moves up and down, plus with the angle that the shaft comes out of the diff, it needs a joint on each end to allow enough movement so the shaft does not bind. This joint is the U joint. With enough hard launches, plus normal wear from vehicle mileage and age (age matters at the grease in the Vipers non grease-able joints will eventually dry up), the U joints will start to need attention. How do you know if your U joint is getting there? There is a few different ways ranging from reaching higher mileage to it letting go during a hard launch.
For me, I had a half shaft break a few years ago while at a drag strip (not the U joint, I actually broke the shaft due to old tires and axle hop). I replaced with one that was purchased used from another VCA member and just installed it. Over the cource of the last few years, the abuse and wear has started to wear the already higher mileage half shaft to the point that I could hear squeaking, clicking, and a faint grinding that did not “feel” right. I mostly noticed this at slow speeds when the window was open.
So I decided to pull it out, and upon removing the straps, the caps fell to the floor! This is a good sign that it is time to replace the U joints!
U joint replacement is very easy. The key will be to have a mechanical press to be able to push the joints out slowly without damaging anything.
Here is an comparison of new and original:
U joint part number and box:
First step is to remove the half shaft from the vehicle. Once removed, you must remove the retaining clips.
Using the press, apply slight pressure to one side of the joint. I used a small length of steel for this that had a smaller diameter than the eye. Once you can see the joint shift, using needle nose pliers and pop the retainer out. Flip half shaft over and do the same to the other side. Once the clip is removed, continue pushing the cap with the steel cylinder. (HINT: You will need to have the bottom side supported all the way around the half shaft ear so it does not break off. If it is not supported it could crack. I found a socket works well so it can still allow the cap space to drop out the bottom.)
Continue pushing until the cap post out the bottom or the U joint bottoms out. Remove cap, flip half shaft over, and again push down on the cap until it pops out.
You can then remove the U joint from the two eyes. You can inspect the old caps for signs of wear. The needle bearings should be clean and in one piece. If you see debris, your bearing needles were fryin’.
Old on left, new on right:
Close up of new (observe the good needle bearings in the caps):
Repeat for other side.
Once both joints are removed, clean up the half shaft. Ensure that it is clean with no dirt on either end, especially around the eyes.
Using a new U joint, remove two of the caps. Ensuring not to nick or scrape the surface of the now exposed bearing needle surface, slide it into the two eyes. Doing the exact opposite as before, slide a cap onto one of the end and press it back into the eye until in approx seating position. Next, push the cap into the other end.
When at the seating point on both sides, press one side just a bit further and install the retaining clip. Then press it back the opposite direction to install the other side. Then try to even the pressure out so it is not loaded on one side more than the other.
Repeat the other side.
The finished shaft will look like this:
For installing into the car, again be very cautious not to knock the caps off. I found it easiest to remove the two other caps when putting the half shaft back thought the shock support. If you also do this be very sure to not get ANY dirt or even bumping the exposed ends! If you do, may as well pull it back out and replace the U joint now.
Once back in, re-strap the joints to the hubs and diff with NEW straps and you are done! Why new straps? The U joint straps are slightly straighter than the arc they need to be. This way when it is torque, it shapes itself to the joint cap. If you use the same strap, when you finish torquing the strap, it may be fully tight by way of the bolts, but the cap could have a different tolerance than the last and it would then not provide adequate clamping force for the joint. You would essentially have a loose cap. The result? First hard shift or clutch drop and you just ripped your U joint out.
That’s it! Repeat for the other side of the car and be sure to mark the mileage in your maintenance book!
Have fun!
Robert
me, this is the way I did it. It does NOT mean it is the right way, or the only way!
