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Tips and tricks for removing clutches and flywheels
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evansut7
post Feb 15 2010, 09:41 PM
IP: 69.207.146.185 | Post #1 |
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After reading a lot of threads on frustrations with clutches and pullers I decided to write up a little guide on removing them based on my own experiences both good and bad, some engineering insight, and tips I have picked up off the forums here. Sometimes there is no easy way to get the clutch or flywheel off but if you have everything set up optimally you can minimize your chances of getting hurt or damaging your sled. Most of these tips apply to the flywheel too. I know I have read a lot more tips on here so post away if you got anything.
The Do's and Dont's.
Do: Lubricate the puller. Not just the tip but the threads also. Loctite (the company) advises that depending on the material, coefficient of friction between fasteners can be over .3 which means you are losing over 30% of your torque to friction. This is on new fasteners, on the old corroded threads of your puller and clutch it is certainly higher. You should be able to seat the puller by hand, if not spray some lube on the threads and run the puller through a few times to clean out any corrosion.
Do: Snug up puller manually before trying to use any sort of impact tool. Unless you manage to pop off the clutch easily right off the bat you run a great risk of destroying the threads on the clutch. Depending on your impact wrench they can have a lot of inertia behind them and you dont want to suddenly jam onto the threads. Due to imperfections of the threads, one thread is going to catch before the rest and they will fall like dominos if you come in with a full head of steam. You need to slowly yield the threads into place to maximize your contact points. Think machete in the jungle, you want to push the branches away not hack them to pieces!
Do: Use a lever longer than a standard wrench if it doesnt come off easy. Trying to exert yourself onto a short wrench is only going to leave you frustrated and with bloody knuckles. I have a big piece of black pipe about 3 feet long that I stick onto the end of a breaker bar. Adding just an extra foot onto a 1 foot long breaker bar will double the amount of force at the end. Work smarter not harder. Which leads me to the warning below...
Do NOT: Use the long lever with a ratchet or with cheap sockets. I have broken many sockets and ratchet wrenches using the above described lever method. Ratchets aren't designed to take that kind of stress, and frankly breaker bars aren't really either but they are a lot stronger than ratchets. If you feel something yielding, back off and see where it is coming from before something breaks.
Do NOT: Try to wedge the clutch with a screw driver somewhere on the chassis to keep things from moving. If it slips, which it almost certainly will, you are going to hurt yourself. Get yourself a good strap wrench that fits over the clutch or try the rope through the spark plug hole trick described below.
Do NOT: Hammer to hard on the end of the puller. Sometimes a couple taps on the end of the puller when its tight is all you need to break things loose but remember, the puller is on the end of the crank! Don't get carried away. The idea is to break the connection between the tapered crank and clutch, not hammer it further on.
Do NOT: Use extensions or deep sockets. High risk of rounding off the threads or breaking the puller off in the clutch. Maybe if things were put together in the last 5 years an extension would be OK but on a stubborn clutch you need everything in your favor.
Why:
There are at least a couple reasons why the clutch is going to be a pain to get off. Knowing what you are up against may help.
#1 galvanic corrosion. Amplified by the snow and salty environment of winter plus meshing together for the last 30 years, the clutch and crank react with each other and corrode together. I don't think Kawasaki uses or recommends using anti seize on the clutch. I don't and you should be OK without it if you keep everything dry and clean when you put it back together.
#2 Improper clutch installation. Over torquing or worse yet using an impact wrench to install the clutch can lead to a clutch that may be impossible to remove. The bolt securing the clutch to the crank is capable of supplying 20,000+ lbs of force on the tapered shaft of the crank. Add in the mechanical advantage of the taper and you may never get it off if it was over torqued. Remember that static friction is higher than kinetic so you may be able to drive it on but getting it off is another story.
Systematic approach to removing the clutch:
1. Remove clutch retaining bolt and conical washers. Duh. Use a strap wrench or a length of rope in the spark plug hole with one end hanging out to hold things steady.
2. Lubricate the threads and tip of the puller with grease or spray lubricant.
3. Screw in the puller with your fingers. If it is to tight to screw in use a wrench and screw it in and out a few times, spraying with lube as you pull it out to rinse off corrosion. If you have the right size tap you can run a tap in there but its pretty deep and really shouldn't be necessary. The goal is to minimize friction losses on the threads and tip of the puller. Also you want to make sure you aren't cross threading the puller into the clutch.
4. Using a good length ratchet screw in the puller snug and tighten as well as you can. If the clutch doesn't come off, move on to step 5a or b. If it does move on to step 6.
5a. If you have one now would be the time to use an impact wrench. This is my preferred method of removing clutches and flywheels. The key is to make sure you don't lose control of the wrench. It is a very powerful tool and letting it free wheel at 3000rpms to a dead stop into your threads can cause a lot of damage. You most likely wont need to use a strap wrench over the clutch. If the clutch doesnt pop right off stop for a minute and assess the situation. Take the puller out and make sure it isnt buckling and there are no metal shavings.
5b. If you dont have a impact wrench get out the breaker bar and be careful. If you hear cracking or feel jumps in your pressure stop for a minute! Take a look at whats going on. Smooth drops/jumps in pressure is the feeling of material somewhere permanently deforming and this is not good. Sharp jumps in pressure usually audible too is something slipping, most likely friction in the threads or the tip of the puller. Either way you have to make a judgment call as to whether to take it out and relube, keep going, or take a break and come back later. Sometimes just letting it sit will help.
6. Replace your crank seals.
Some notes:
The clutch has a sleeve in it for the puller threads and seating surface. It looks like some sort of aluminum bronze but im not sure. Anyone know for certain?
Assuming the threads have not been damaged the weakest link in the system should be buckling of the puller. If it does buckle there may be nothing you can do. I dont know if any available puller is better than another. As a last resort you may be able to match up a bolt to the threads of the puller but you will be seating right on the threads on the crank. Not a good situation as you may damage the crank and you definitely dont want to do that.
If you stripped the threads in the clutch I don't really have a good solution. I think maybe your best bet would be to use a heli coil thread repair kit but the problem is the threads are so deep in the clutch, not to mention still stuck on the sled. Heli coils have there own taps so you wouldnt have to remove to much material from inside the clutch. You may be able to take the whole clutch apart down to the sleeve and use a gear puller on the back side, or destroy the sleeve to get it off. This would be a last resort but if you have no threads your back is kind of against the wall anyway.
Usually the key to getting off a stubborn clutch or flywheel is impact. Using an impact wrench or a couple taps on the end of the puller with a hammer will most of the time do the trick. I have not come across a bolt or nut I haven't been able to remove with the impact wrench one way or another but you need to know the limits of what you are working on and have a feel for when things are going to break or bend.
I would stay away from heat, in this case I dont think it is going to buy you much and I dont think it is really necessary. Open flames near an engine is a disaster waiting to happen. Heat on your clutch will also temper and weaken the material.
There is a point right before a fastener or tool breaks where there is an increase in strain without any increase in stress. Basically what that means is you will be stretching the fastener/tool without increasing pressure and its going to feel a little weird. If you have ever broken a bolt you have probably felt this before. If you feel this stop! A. The tool/fastener has already been damaged beyond repair and B. If whatever you are wrenching on hasn't come off by now its not going to because you aren't increasing pressure anymore, you are just stretching until it breaks. Fix whatever is happening because its easier to remove a bolt before it breaks than after. Its also easier to not smash your knuckles into an ice cold chassis than is to full force punch your sled when something breaks.
Topic: Tips and tricks for removing clutches and flywheels (Read 7452 times)