To make a long story short, I busted the 4wd on Loretta's 284.
Ever since reading about how careful to be ... not using 4wd when using the loader for example, we have been using it sparingly and only when needed. Well, when I was using her 284 to rip trenches for the sprinkler systems, I needed to use 4wd to pull through the hard Earth. I heard (and felt) that the 4wd was no longer working properly.
But it was strange ...
It felt like it wanted to spin the fronts and did at times, but then it would slip making a "click click click" noise. It seemed like the 4wd was still working except under heavy load. That's when it would "click" over and the fronts would not spin (no 4wd) at that time.
Anyway, there have been several threads about 4wd not working so I read up on them and the other links.
It seemed that many of them had to do with the 6 steel balls at each end of the front drive shaft perhaps coming out of there position. But there were also some where the front axle broke. So the first thing I did was jack up the tractor (all 4 wheels off the ground). Then I started turning the front tires. The front drives seemed to be OK and so did the front differential. There was no grinding noise whatsoever and when I turned one front, the other tire turned in the opposite direction. I jerked them back and forth quickly to see if anything sounded broke in there, but it all seemed good.
I removed the cover to the transfer case and physically checked to see it the gears were good. I also checked to see if the lever was moving the engaging gear from 2wd to 4wd and that was OK too. Then I started to remove the front drive shaft. After removing the cross brace on the bottom that covers up part of the drive shaft, I removed the hose clamps and slid the cover back to expose the front engagement. I removed the snap ring (which was good) and saw that the 6 steel balls were all in there behind the star shaped washer. I did the same to the rear engagement and looked at it too and it seemed just fine.
I decided to lower the fronts only and leave the rears jacked up but on a rolling floor jack. I carefully started the tractor, put it reverse and gently let the clutch out. Well, the tractor moved ... the fronts were engaging alright!! I did it in forward and same thing. So the 4wd did work under light load but slipped under heavy load. At that point I was pretty perplexed and decided to call Tommy at Affordable Tractor for his advice. He explained several possibilities and told me I should have completely removed the front drive shaft. Dang, I knew I should have done that and not just "eyeballed" the joints.
After explaining to him what the tractor was doing, I asked if it was possible for the balls to wear a groove in the splines so they had to "jump over" the splines? Because that is what it seemed like it was doing ... that thought was going through my mind when the tractor was acting like I described. He said it was possible. In any case, he said he had all the parts I would need no matter what.
So I jacked the tractor back up and removed the front drive shaft.
First photo shows the front engagement which I left on the tractor because it was so clean and perfect. Second photo shows the front part of the drive shaft with the grooves for the balls. The snap ring and star washer (ball keeper) were in great shape too. Oh, and my chickens were keeping company while working...
Rob-
I have discovered that front wheel bearings (roller) for 60's/70/s GM A-body will fit. They are 7.86 od but they are a little long. A littlie grinding and they will seat perfectly. If your groves are little worn worn, they will fit right in and would be an easy upgrade. Gonna try it tonight.
