Hi, I am trying to remove the tach drive from my 508B. It is in the block between the starter and power steering pump. There is access to it and I can get it to turn alittle but thats it. The new one looks like it is just pushed into the block no threads? What is the best way to remove it? I was thinking maybe a slide hammer but, the threads for the cable are female. Any help would be great. It is #30 in the picture. :drinkup
The drive does come out hard if it has been in there a while, and it has to come out to get the camshaft out, as I recall. Ideally you need a nut that will screw on the thread but I've never been able to match the thread. A standard NF thread nut comes close and will get it out in a pinch, if made into a puller. The damage to the thread can be cleaned up with a thread file or needle file. Sometimes just prying up on both sides of the nut will pull it out. The thread pitch Case uses could be matched up by taking the tach cable into a bolt and nut supply store and they will use a thread gauge on it. Or you can purchase an Imperial thread gauge, yourself, then see if a nut is available. There are many pitches available, not just NC and NF that we normally work with, sometimes called machine threads. Shop Floor Talk forum would help you identify a fastener to thread on and where to buy it. I'm sure Case made a tool for this. An old tach cable end might be used, possibly this could be made into a puller, but it is made of aluminum. Phil
I had the same problem with my Case 680C with the 301B diesel engine . Your 580 looks identical. This is how I removed it. I removed the drive assembly by drilling out the center of a 3/4 inch-16 TPI grade 8 cap screw.I was then able to quite easily screw the cap screw into the drive assembly. There is a threaded hole in the engine block for jack bolts on each side where I screwed in the cap screw.I simply put a 5/16 thick x4"long strap under the head of the cap screw and backed out the jack screws. The drive assembly came out with no problem.
screw a set of vise grips to a slide hammer and it should pop out.
Would you please explain Rhinos? I cannot picture a way to connect vicegrips to a slide hammer and still be able to use the vice end. Thanks, Jody
I like this idea. The only problem is I am in New Jersey and the machine is in PA at our property and I left everything up there. Do you have any drawings or measurements that I could go from? Thanks, Jody
Take the adjuting bolt from the vise grips and weld it toa nut that fits a slide hammer. then just screw it back together and there you go. Have found that with this new tool, have used it to remove alot of other thing. Like pulling pins, gears,etc.
elcactus, If I can find the puller tomorrow I will take a photo of it and post.
I believe the 301 tach drive is different, it has an internal thread I think. The vice grip mod is interesting. Good luck, Phil
Yes, mine has a internal thread nulike the 580C that is external. I have a few weeks before I go back there and plan to make up the vice grip and puller. If you can get a picture that would help alot. Thanks for your help. Jody
Here is a crude drawing of my puller. Since you only have one bolt hole in the engine block you will need the bottom plate that is outlined in yellow. Drill a shallow hole in the lower plate on the side where there is no hole in the block . That will stabilize the threaded rod form creeping out of alignment when you are turning the jack nuts. Drill oversize holes in the plates so you have room to align everything up. I used an old lawn mower blade cut up for the plates. As previously stated in another reply the tach drive has an unusual thread pitch. The 16 TPI bolt will stretch the tach drive threads, but it screwed in easily and square for me. If anyone plans on reusing their tach drive I wouldn't recommend using that particular bolt. I cored out the 3/4 inch bolt with a 3/8 inch bit.Maybe someone else can add some more input to my puller.
Thank you Tinkerer :drinkup I will start getting stuff together. I am going there the weekend of October 3rd so I won't know much before that. I will post when I return and let everyone know how it worked out. I also plan on making up a pair of vicegrips for the slide hammer just in case. I think I will have lots of uses for them. Thankyou, everone for your help! I was thinking I would have to pull the oil pan and use a punch to drive the tachometer drive out. Lots of good help and a great bunch of people. Jody
its not an easy deal When I overhauled our 580B, I had to destroy it to get it out. If your pan is off you can drive it from the bottem, if not you will have to do the vice grip trick. It will crater it. Good luck
First post - I have been reading stuff related to the 580b on this forum since I’ve owned mine (approximately 2 years) and it has definitely helped me out with my machine. Mine in particular is a 1975 with power shuttle with extendahoe and open ROPS and I’ve slowly been making improvements. When installing the new tach drive gear, as it I pressed in place is there any gasket or seal to be used? Is there any worry about sloppiness/slack or leaking for that matter when the new drive gear is installed? Any info on this would be greatly appreciated! Thanks in advance. JGuild
There is no gasket or seal for the tach drive the press fit will keep the oil from coming out.
Thanks, Coy. Maybe one day I’ll get some time to remove the existing and install the new one. JGuild
I used to have a tool made up that I used to remove the tach drives. I'll have to find it and get you the thread pitch on plug I used to screw into drive.
That would be great! From what I’ve read elsewhere in this thread and another thread in this forum, removing these can be a bit tricky. Anything to simplify the process would be awesome!
Hey here is the end I used for removing the internal thread tach drive on 580 tlb’s with 188 or 207. It’s a hex plug that was actually in a tach drive on an old engine. The thread pitch is 18 diameter is 3/4 there about. I don’t know why it doubled on photo.
Sweet, thanks! So once you got that plug in, what was your method for removal? Did you just pry on the head of that plug?
I welded a piece of 1/2" allthread to the plug and found a piece of pipe that fit around the tach drive area and welded a large washer on top put the allthread through it and put a nut on it then used it as a puller. The weld broke later on in years and I haven't needed it sense so I haven't put it back together. I couldn't find the rest of it. Another thing you can do which I just thought of is that you can weld a nut to the top of the drive and either use a slide hammer or puller.
I like your idea that you used. Seems simple enough. I think I’ll give that a go when I get around to it. Thanks again for the info and the photos.
Hey, Coy. I’m at my local case dealer now picking up the tach cable. Just to be clear, there are no seals or o-rings that should be in place on the tach drive gear itself when it is put in place in the block?