Up-and-down play / slop in NP241OR front output yoke after rebuild

[StrassBass98]

After replacing the axle side U joint in my driveshaft, I went down a rabbit hole trying to chase down a pretty substantial vibration that occurs at about 65mph. It's bad enough that it makes the change in my cupholder buzz.

At first, I thought it was my driveshaft, but after removing the driveshaft I found that the front output yoke on my transfer case had up and down movement in it. It's enough that if you grab it, will make a clunk noise. I removed the transfer case and rebuilt it, wasn't too bad. There weren't any substantial metal shavings in the case. I replaced all the bearings and seals, put everything back together and torqued to spec. Unfortunately, I couldn't really torque it until it was back in the Jeep, so you can imagine how annoyed I was when it didn't solve the problem. The wiggle is still pretty much the same.

All the bearings on the front output side drove in and out fine, with minor difficulty. There are only two, the cage needle type on the back half of the case, and the other normal bearing at the front. I don't think the needle bearing is the issue, as it was very difficult to drive in and pull out, which indicated to me that there wasn't case wear. I thought maybe that the drive sprocket and output shaft might have play, so I bought a used one to compare it to, however they feel exactly the same.

I think this pretty much narrows it down to the front case half bearing race being worn out, allowing the bearing to move around. I am not sure what else it could be, unless maybe the output yoke is worn out in some way? It has good spline engagement so I'm reasonably certain that's not the issue here.

As an aside, nothing was leaking before or after the rebuild.

If anyone has any advice or dealt with a similar issue, or has any advice please let me know.

 

[Chris]

After replacing the axle side U joint in my driveshaft, I went down a rabbit hole trying to chase down a pretty substantial vibration that occurs at about 65mph. It's bad enough that it makes the change in my cupholder buzz.

At first, I thought it was my driveshaft, but after removing the driveshaft I found that the front output yoke on my transfer case had up and down movement in it. It's enough that if you grab it, will make a clunk noise. I removed the transfer case and rebuilt it, wasn't too bad. There weren't any substantial metal shavings in the case. I replaced all the bearings and seals, put everything back together and torqued to spec. Unfortunately, I couldn't really torque it until it was back in the Jeep, so you can imagine how annoyed I was when it didn't solve the problem. The wiggle is still pretty much the same.

All the bearings on the front output side drove in and out fine, with minor difficulty. There are only two, the cage needle type on the back half of the case, and the other normal bearing at the front. I don't think the needle bearing is the issue, as it was very difficult to drive in and pull out, which indicated to me that there wasn't case wear. I thought maybe that the drive sprocket and output shaft might have play, so I bought a used one to compare it to, however they feel exactly the same.

I think this pretty much narrows it down to the front case half bearing race being worn out, allowing the bearing to move around. I am not sure what else it could be, unless maybe the output yoke is worn out in some way? It has good spline engagement so I'm reasonably certain that's not the issue here.

As an aside, nothing was leaking before or after the rebuild.

If anyone has any advice or dealt with a similar issue, or has any advice please let me know.

Given that the bearings you replaced went in and out with minor difficulty, I agree with your assessment that they likely weren't the issue. It’s a good idea to check for any wear on the front case half bearing race, as that could definitely contribute to play and clunking noises.

Also, while it sounds like the spline engagement is solid, don’t dismiss checking the output yoke itself closely for any wear or irregularities that may not be visible at a glance. Sometimes even slight wear can lead to excess play. Another common culprit could be the transfer case's output housing. If it has any internal wear or is deformed in a way that allows for movement, that could certainly cause the issue you're experiencing.

Since you’ve detailed that there are no leaks, it’s a good sign that seals and gaskets are intact, but I’d also recommend double-checking all installation points to ensure everything is torqued down correctly once more, as the pressure can sometimes lead to unexpected movement in components.

Lastly, it might be worthwhile to completely disassemble the output yoke and inspect the splines and any other components for wear. If the yoke is the original part, it could be time for a replacement if repairs don’t yield results.

Keep us posted on what you find, and good luck—vibrations can be tricky to diagnose but getting this sorted out will be worth it!