U joint and center bearing time!

[jayoldschool]

Picked up my center bearing today on the way home, so I thought I would do a little work before supper. Use my new ball joint/u joint kit for the u joints. Driven by my air impact, it worked well.



Time for a new bearing? Yes, I think so. I could grab the drive shaft and move it about an inch!



Quick question. One one shaft, the yokes are in phase. On the shaft with the bearing, the yokes are 90 apart. Should they be in phase? Just want to make sure I put things back together the way they are supposed to be when I press the bearing on.

[geezer#99]

THe piece with the bearing on it is wrong. Needs to look like the other piece. Yolks on the same plane. Turn the splines end 90 degrees.
Like here.
http://www.vibratesoftware.com/html_....htm#Propshaft Phasing

[jayoldschool]

Exactly what I thought, and probably one of the reasons why that bearing failed. It had been replaced (doesn't look as "old" as everything else), and the U joints were greasable, so I'll guess they were changed, too. It will get all new!

[jayoldschool]

Two steps forward, one step back.

Took the driveshaft to the school shop today (I'm a teacher), and went to press out that yoke. Pressed on the bolt. Heard that nice "ting!" noise that two pieces make when they move apart. Unfortunately, I discovered the noise was the bolt skipping threads in the yoke and destroying the threads. No threads left on the bolt when I had to use an impact to back it out. The yoke will need to be tapped for a larger bolt.

Advice on exactly how to take the yoke/bearing apart? I want to make sure I am supporting the right part, and pressing on the correct area. I've got the outer rubber/casing off the bearing. When apart, does the bearing stay with the shaft or the yoke? I guessed the yoke, and held the bearing while pressing on the center of the shaft through the yoke. I'm thinking I had it backwards. I was trying to do this on a shop press.

See this photo from rocktonka for what I'm talking about.

[rustbucket66]

You should have marked the yoke and shaft so it can be put back on the same way. There are two ways you can put the yoke on and have it in phase. One is the way it was on when it was balanced, the other way it is 180 degrees out and not balanced. The heavier side of the yoke then would be on the same side as the balance weight, and would be way out of balance. As for the bearing, torch off the outer part of the bearing, then heat the inner part of the bearing red hot, and it should knock off easily with a hammer and chisel. Sand the shaft with emery cloth before installing the new one. Might be a good idea to get the shaft balanced again.

[jayoldschool]

I did mark everything. As you can see in the third pic, the PO installed the middle yoke out 90 degrees, so that will have to go back in the correct way.

[jayoldschool]

Back with updates! Got the yoke out using the press. The bearing would not budge even with my full weight on the foot pedal of the press. So, took the torch to it, cut it, and popped it off with a hammer. Cleaned up the splines with a wire wheel so the new bearing will slide on nicely.

Now I have to deal with the stripped threads in the end of the shaft. I took a look and only the first 1/4" or so are damaged, so I should be able to chase them and reuse the good threads that go deeper. I believe they are 1/2 fine, but if anyone knows for sure, I'd appreciate it!

[jayoldschool]

Anyone have an idea of that bolt size/thread that holds the yoke on? I'm back in the shop tomorrow and want to get it right.

[fleetsidelarry]

I only know that they are fine. 1/2 sound right but I can't say for certain.

I'm not clear how the bolt stripped by pressing on it, but it doesn't really matter now, of course. as you know now but for the information of others, the bearing doesn't really "stay" with the yoke OR the shaft, it fits snug on the shaft and is held in place by the yoke. the yoke is held on by a bolt and washer. take the bolt out, press off the yoke, then the bearing or both together.

Point of interest: this is what my yoke looks like, it only went on one way as the shaft had a wide "spline" to match. only way to be out of phase was for the shaft (shortened for a 700r) to be built that way. Yours not like this?:



also, here's something interesting from Spicer regarding phasing of front shafts:

"Check the actual universal joint operating angle at the rear of the first coupling shaft. If it is less than 1º and the transmission
universal joint operating angle is greater than 1.5º, rotate the end yoke at the center bearing position so that the ears of the yoke
are 90º to the ears of the tube yoke on the transmission end of the coupling shaft. (See Fig. 10) As an alternative, rotate the slip
yoke on the driveshaft 90º if the slip spline has 16 teeth"

http://www2.dana.com/pdf/J3311-1-HVTSS.PDF

[jayoldschool]

The threads got stripped because I was pressing on the bolt to remove the yoke. I had not put the bolt in all the way, so the force caused the bolt to tear the threads off the bolt. A stupid mistake.

My yoke has a wide spline like that, but the shaft does not. The splines are equidistant, just like the photo that I posted with the shaft in the vise. When I went to put everything back together today, I learned that the only way to install the yoke is to have it 90 off the fixed yoke at the other end. The closest spline alignment to "even" with the other one would put the yoke off by about 15 degrees. So, I put it back on 90 off, the way it was in my initial post. Bearing slid right on, I drove the yoke/bearing home with a couple taps on a big socket.

Thanks for that pdf, it makes sense, and it makes me believe that the way the yokes are in my original pic is the factory way.



Thought I found a good bolt that threaded in, but it had a shoulder so I couldn't seat it deep enough. Went to Lowes, and learned that it was M12x1.5, definitely not correct. No one had 1/2x20, so I stopped at my local tractor place and they had one. Can't get it to bite on the threads that I screwed up, so I'll re-tap tomorrow.

U joints next!

[jayoldschool]

Gave the threads a quick chase with the 1/2x20 tap, and the fresh bolt worked perfectly.

[jayoldschool]

All done. Fresh USA made U joints went in nicely after I cleaned up the yokes. Even remembered to align everything the same way they came out. One more thing crossed off the list!