Guitarhacker 5 #1 Posted September 13, 2016 (edited) I inherited a 604 model tractor which I needed to get working. It had set idle for quite a few years. I have it running nicely now but have a reoccuring issue with the stick shift on the transmission. It's a 4 speed tractor.... 3 forward gears and one reverse. The transmission seems solid and works well. My problem is with the shifter itself. It has come out a number of times. When I got the tractor, the shifter was held in with a bolt through the side of the transmission case and into the shifter. It sheared off and I had the hole welded and retapped. I installed a new bolt but it has sheared off today. So I find myself back at the beginning.... drilling it out, for sure, more carefully this time, and having to replace the bolt. I'm thinking there has to be a better way, or perhaps even the right way to hold the shifter in place. I don't want to be doing this every few weeks. Anyone got some ideas or perhaps even an exploded diagram showing the right way to secure the shifter so it doesn't fall out, doesn't shear bolts, and works like it's supposed to? Edited September 15, 2016 by Guitarhacker solved issue Share this post Link to post Share on other sites
gwest_ca-(File Mod) 11,107 #3 Posted September 13, 2016 You need a dog point set screw. The point enters the hole in the shifter donut and provides the pivot point. A 1/4" nut is added to the outside and snugged up when the set screw is adjusted for a smooth shift. This locks the set screw in place. Once done the shifter boot is placed over the screw/nut and it holds it down. Garry 3 Share this post Link to post Share on other sites
Guitarhacker 5 #4 Posted September 13, 2016 36 minutes ago, gwest_ca said: You need a dog point set screw. The point enters the hole in the shifter donut and provides the pivot point. A 1/4" nut is added to the outside and snugged up when the set screw is adjusted for a smooth shift. This locks the set screw in place. Once done the shifter boot is placed over the screw/nut and it holds it down. Garry Now that makes sense. I will have a look at obtaining one of those. I may need to tap the hole slightly larger since my FIL had rigged it up to the condition it's in. I will check the hole and threads tomorrow and get the right things. Share this post Link to post Share on other sites
stevasaurus 22,883 #5 Posted September 13, 2016 On top of what the guys above said. Does the trans actually shift or is it locked up?? Take a long screw driver and try to shift the forks (one at a time). You may have to take the trans apart to free things up. Some pictures would help. The dog point set screw has worked since 1958...there is really no other way to do this. Let's see what you have there. something is not right. 2 Share this post Link to post Share on other sites
KC9KAS 4,741 #6 Posted September 13, 2016 @Guitarhacker and ! Share this post Link to post Share on other sites
Racinbob 11,251 #7 Posted September 13, 2016 Do take some pictures and keep us posted. I can envision problems drilling that hole out larger. If you can keep it at 1/4-20 I've got extra dog point set screws and I'll sent you one. 1 Share this post Link to post Share on other sites
Guitarhacker 5 #8 Posted September 15, 2016 (edited) Well... I got the issue solved. My father in law had rigged it up and did it the wrong way which created the issues I was dealing with. As a result, the 1/4 20 threads were shot. I was given this tractor when we bought the farm, by my mother in law who had kept it in her garage. So, today, I went to the farm and checked to be sure the 1/4 20 was wallowed out and it was. I have a bunch of taps so I went to Lowes and bought a 5/16 x 18 stainless allen head bold and a nut. I went to my house and used the grinder to grind down the threads on the end of the bolt which was a 1.5" bolt. I had to remove the sheared off bolt in the shifter which only took about 10 minutes. A dremel tool, a diamond tip bit and a small flathead screw driver and waaa laaaa... it was out. I checked the end of the bolt to be sure it was the right size and taper. When I thought it was about right, I carried it to the farm where I keep the 604. I used my 5/16 x 18 tap and carefully plugged the hole with a paper napkin to keep metal filings from getting int he transmission. Then I carefully tapped the hole to the size needed. Since the hole was wallowed out, the tap went in nicely and cut new clean threads. When I thought it was deep enough, I removed it and inserted the new bolt and nut. They went in nicely and the nut had sufficient clearance to turn to tighten against the case. I backed it out and inserted the shift lever and then the bolt. Everything tightened up nicely and a few minutes later, I was firing up the beast and checking how it shifts. Needless to say, it works like it is supposed to work now. Thanks for the advice. I have also bolted some metal electrical support stock to the front end, and made a bumper out of some pressure treated 2x6. It's purpose is to hold additional weight to keep the front wheels on the ground when plowing. In the first pic, I had rigged up the seat, but since then, I have fixed the seat properly. It has a back rest that goes with it but I see no real purpose in having it on there at this point. So it's in my shop collecting dust. I may reinstall it later. Edited September 15, 2016 by Guitarhacker 4 Share this post Link to post Share on other sites
stevasaurus 22,883 #9 Posted September 15, 2016 That's what a lot of us like about the horses. Backyard mechanics can still do their thing. Share this post Link to post Share on other sites
