My hand clutches on my D7E were always a little wonkee. Then, about two weeks ago, one of the original "repairs" fell off during use, then they really got wonkee. The bolt with the Nyloc nut in the first photo was my repair to keep things running. Looking at the state of the levers, I had to really fix them properly. Only the right lever pin below was original, but the internals were shot. Looking at the inside of the levers, I tried to figure out what exactly I was looking at. Why were there two ridges on the inside of the hole? It then hit me that these were the remains of needle roller bearings in the original design. The only problem I saw, was there was NO way to grease them short of disassembling the hand clutches and lubing them manually. With that not really being practical, another way was needed to get grease to these bearings.
Taking the clutches to my repair shop, I was able to successfully press out all the remaining shells and clean up the mess left by them. Here's what the pins looked like after 50+ years of neglect. The only one in fairly decent shape was the original, probably because it was hardened. I picked up some needle bearings and some O1 precision stock from McMaster-Carr and went to redesigning the pin. I made the pin approx 1/4" longer and drilled a hole about 3/4 of the way down the center. I then drilled and tapped for a 1/4"x28 TPI grease zerk. I then crossed drilled in the center of the pin and on the end, like the original. I then heated them with a propane torch, then dunked them into used motor oil. I then tempered them to about 57 Rockwell C. I sorry, but I don't have a photo of the finished pins. With most everything ready, it was time to reassemble the handles. I built a simple tool to help press the bearings into place. Here's a photo of the bearings in the handles. I noticed that the original design didn't have any bearing seals, so I took some UHMW Poly and turned some out. They are a press fit into the bearing housing, but years of wear and tear made the fit somewhat "iffy". The purpose of the seals is just to keep water away from the bearings and to provide a fill area for grease. Here's the handles with the seals in place. Here's the handles with everything being test fitted. Everything went together smoothly.
To mount these and have zerk access, the hole for the cotter pins need to be flipped to the other side. Here's me drilling one of the cotter pin holes. The angles are such that I had to use a very long drill bit to be able to get even close to the original angle. You can see a pin being used to guide the bit for the back side hole. This made each pin specifically for a single hole. I numbered the levers and the pins 1 thru 4. You can see the center cross drilled hole for grease exit in this photo. Here's all four pins installed with the cotter pins, with the big pins awaiting for the grease zerks. I didn't pre-install the zerks, because I thought there might be problems getting things together on the dozer. There wasn't. Here are the grease zerks installed and ready to grease. And here we are greasing the hand clutch handles for the first time in decades! The results are a set of clutches that are as smooth as they were on day 1 of this dozer's life. One issue that did come up, is that the zerk on the lower right of the photo above the last one was interfered with by the housing "bump" where the clutches exit. I had to flip the pin around so that the zerk was on the inside. This meant that I also got to use the original cotter pin hole. The zerk is still accessible, so this won't be a problem.
A man after my own heart, who likes controls that are smooth and easy to operate. It makes a big difference to your tiredness at the end of a long day, if you haven't had to fight heavy or worn controls all day long.
It had become a repair of necessity. When the pin on the left control fell out, I was just making a left turn. Because the pin fell out, the clutch hung up - a real pucker moment. Jerking the clutch back and forth real hard (panic mode), the clutch finally came free and I was able to control the dozer back to where I could find out *** happened. I imagine that the pin fell into the belly pan - a place where parts and tools go to die.