I posted a few days ago that I'm helping a friend replace all the bearings and seals in his front axle. Another member PM me a link on how he had his CV joints machined so he could grease them without taking the axle apart. I looked over the link he sent me, and we made up our minds to do this mod. Since i have a full machine shop at my home, all it cost us to do this job was my time.
I set up the CV joint in my lathe to drill the hole for the grease fitting from the bell end first. Using a center drill to first start the hole, then changing that out for a solid carbide stub drill, next i used a jobber length drill, and last, we went to a depth of 3 1/2 inches with an aircraft drill.
I then switch out the lathes 3 jaw chuck, for a four jaw chuck, and indicated in the CV joint with a dial indicator. After i had the part zeroed in, i steady the joint with a steady rest before i started drilling it. I then drilled the joint from the shaft end using the same steps i used for the bell end to complete the grease hole.
As it turned out, the inside of the CV joint in not harden, so drilling the CV joint for a grease fitting was easy. All in all you only need to drill through about 6 inches of steel. We went with a 3/16 hole to pump grease into the joint, so as to not weaken the joint.
We wanted to save, and use the factory 9MM X 1.25 threads in the end of CV shaft. The reason we did this, is so i wouldn't have to make a large counter bore in the end of the CV joint for a zerk fitting.
The problem doing the mod this way, you can't buy zerk fittings with 9MM X1.25 threads. So that means i needed to make an adapter to mount the zerk fitting to the joint. I made an adapter out of an Allen bolt, one end was threaded 9MM X 1.25, and the other end i machined for a 10/32 zerk fitting. When the zerk fitting isn't in use, the grease holes in the CV joints are blocked closed with a short 9MM X 1.25 set screw.
Now when he does his oil change, all he needs to do to grease his CV joints, is to remove his wheel center hub cap, pull the dust cover, remove the set screw, install the zerk fitting, and pump in some grease. Now how easy is that!
I set up the CV joint in my lathe to drill the hole for the grease fitting from the bell end first. Using a center drill to first start the hole, then changing that out for a solid carbide stub drill, next i used a jobber length drill, and last, we went to a depth of 3 1/2 inches with an aircraft drill.
I then switch out the lathes 3 jaw chuck, for a four jaw chuck, and indicated in the CV joint with a dial indicator. After i had the part zeroed in, i steady the joint with a steady rest before i started drilling it. I then drilled the joint from the shaft end using the same steps i used for the bell end to complete the grease hole.
As it turned out, the inside of the CV joint in not harden, so drilling the CV joint for a grease fitting was easy. All in all you only need to drill through about 6 inches of steel. We went with a 3/16 hole to pump grease into the joint, so as to not weaken the joint.
We wanted to save, and use the factory 9MM X 1.25 threads in the end of CV shaft. The reason we did this, is so i wouldn't have to make a large counter bore in the end of the CV joint for a zerk fitting.
The problem doing the mod this way, you can't buy zerk fittings with 9MM X1.25 threads. So that means i needed to make an adapter to mount the zerk fitting to the joint. I made an adapter out of an Allen bolt, one end was threaded 9MM X 1.25, and the other end i machined for a 10/32 zerk fitting. When the zerk fitting isn't in use, the grease holes in the CV joints are blocked closed with a short 9MM X 1.25 set screw.
Now when he does his oil change, all he needs to do to grease his CV joints, is to remove his wheel center hub cap, pull the dust cover, remove the set screw, install the zerk fitting, and pump in some grease. Now how easy is that!
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