PaulC 341 #1 Posted October 28, 2014 Just swapped a good running magnum 12 from a 312-8 onto my 312-A. Got everything set and then realized the drive belt pulleys are different sizes, the one from the manual tractor is much smaller then for the hydro. I got the pto pulleys and clutch plate off of both engines but cant get the drive belt pulley free. All set screws loose and got the keyway to move on the one but cant get either pulley to budge. I sprayed both with pb blaster and plan to try to remove them with a puller. Assuming thats the best way but thought id check here to see what others have done? Thanks Paul Share this post Link to post Share on other sites
daveoman1966 3,627 #2 Posted October 28, 2014 These are cast iron pulleys and will EASILY break. Definitely use a puller, but NOT the type with hooks that grab the pulley on the back side. Use the style that has to be bolted to the face of the pulley. Share this post Link to post Share on other sites
PaulC 341 #3 Posted October 28, 2014 Thanks Dave I was going to use the finer type but guess I should know not to considering I broke a chunk of one of the pulleys yesterday by prying with a pry bar, good thing it was the pulley I wont be using. I can easily make one now that you mention that type. They are 1/4-20 holes on the pulleys correct? Share this post Link to post Share on other sites
zieg72 209 #4 Posted October 28, 2014 Take the set screws out and position the holes at 10 and 2. Fill up with PB Blaster, let soak. It took me several hours but I finally got it to move with prying ever so gently side to side. I broke one before. If you use a puller make sure you use grade 8 (1/2- 20)'s Share this post Link to post Share on other sites
daveoman1966 3,627 #5 Posted October 28, 2014 Thanks Dave I was going to use the finer type but guess I should know not to considering I broke a chunk of one of the pulleys yesterday by prying with a pry bar, good thing it was the pulley I wont be using. I can easily make one now that you mention that type. They are 1/4-20 holes on the pulleys correct? 1/4 - 20 is correct. make sure they are threaded CMPLETELY thru the pulley stock....evenly too. Share this post Link to post Share on other sites
AMC RULES 36,954 #6 Posted October 28, 2014 Paul, if you do make a puller... please share a pict here. Share this post Link to post Share on other sites
PaulC 341 #7 Posted October 28, 2014 Zieg that is a great idea I did spray them but your way would allow it to really get where it needs to go. Guessing you made a typo when you said 1/2-20's? Thanks again for the info Dave U got it Craig!!! You are a lush when it comes to pictures Share this post Link to post Share on other sites
AMC RULES 36,954 #8 Posted October 28, 2014 Actually... would just like to see a puller that works. 1 Share this post Link to post Share on other sites
PaulC 341 #9 Posted October 28, 2014 haha just messing with ya craig. ouch....the pulley I don't need looks similar. that pulley you show doesn't have the 1/4-20 screws were talking about though? the puller I have in mind wouldn't help with that pulley. I will add some pics to this thread though when I get it straightened out. 1 Share this post Link to post Share on other sites
PaulC 341 #10 Posted October 29, 2014 Well guys I made my puller on lunch yesterday took about a half hour good news is it worked excellent and got both pulleys off no problem!! I was driving my now "non-smoking" 312-A around the yard about an hour after I got home....so glad it finally kicked the habit used 1/4" plate 4"x4". Drilled a 1/2 hole dead center and then .281 holes at 5/8 and 1 1/2 in four directions 90 degrees apart then connected those holes with a torch. Welded a 1/2-13 nut in the center and got some hardware. They still came off kind of tough so I couldn't imagine ever getting them off without this. 1 Share this post Link to post Share on other sites
zieg72 209 #11 Posted October 29, 2014 Zieg that is a great idea I did spray them but your way would allow it to really get where it needs to go. Guessing you made a typo when you said 1/2-20's? Thanks again for the info Dave U got it Craig!!! You are a lush when it comes to pictures Yep typo, fat fingers...sorry. Love the puller you made Share this post Link to post Share on other sites
