Hmm, sounds like it’s probably stuck on the keyway. If you’re getting new parts, just keep hitting it until it shocks it loose… I generally use a wedge in these situations.
Wait… the bolt? Isn’t it held on by several little bolts? Yeah, 4 little bolts around the 1 big one.
My crankshaft pulley on my mk1 was straight up welded to my crankshaft with all the corrosion. I tried plenty of penetrant and rubber mallet whacking, but it didn’t budge. In the end I bought a set of pulley pullers from screwfix for £40, which eventually got it off, though I’d only recommend it as a last resort. The sheer amount of tension and compression in what is admittedly pretty cheap metal was unnerving honestly.
If you wanna go this route, set your puller arms on an edge that’s not gonna slip (for me that was the inside of the V-belt slot), and start to gradually tighten it down. Lather with penetrant, hit with rubber mallet, tighten puller, rinse and repeat. Best to do it with the crankshaft bolt in so you have something solid to push against.
Thank You Ron, for your reply. Most suggest hat, 'it’s fiddly to remove those four small bolts; however, when I have the new damper and the car is returned to the garage, I’ll certainly mention this to the chap who’ll be undertaking the work.
Thank You for taking the time to reply to my , ‘Frozen Damper Pulley Problem’.
When I have the new Damper and trigger disk plate and I take the car back to the garage, then I’ll most certainly mention your method of removing the Damper / Pulley assembly, from the crank nose.
Think I also better obtain a new woodruff key, just in case!
The bolts only hold the pulley/harmonic damper to the hub. The hub is a keyed, parallel fit on the crankshaft, held on by the Big Bolt in the middle. If the assembly is stuck on the crankshaft, taking the 4 little bolts out won’t make any difference to getting it off the crank.
However, I don’t know whether removing the pulley/damper from the hub would give enough access to remove the covers, etc. needed for timing belt replacement.
Getting the pulley off the hub (which will probably be a mission in itself) will allow removal of the covers and may allow more access for removing the hub but the hub needs to come off to get the belt off & on.
Actually, it is possible, although not recommended, to get that belt on with the hub still on. You just have to be clever with the tensioner. Helps if you have the tools to lock the crank and the cams, although I’ve only got a crank locker and managed to do it. Granted this was on a mk1 but I can’t see it being massively different. I can’t remember what led me to do it like that as I had no trouble getting the pulleys and hub off, I think I was just questioning myself at one stage (1st unsupervised cam belt) so went through a few stages just to get things straight in my head, and I’m sure one of the things I did was put the old belt back on with the hub on the keyway. Unless the hub is not the bit I think it is…
I seem to remember always taking the pulleys off before I do anything else and not having to struggle, then again I have a crank locking tool. Was 15 quid from a fabricator a couple of towns away. I think it’s formed the wrong way as it only locks 180 degrees out of the mark, and it got deformed after the 2nd belt but is still usable.
Another thing I will add is that some people just lack patience and finesse and even an understanding of the forces involved holding things together, even those whom you’d think would have it. I’ve removed things by hand and with small levers that others have struggled with with bigger levers and insisted on going to get a puller or such, when all they really needed was a bit of finesse and thought. Sometimes, especially when dealing with tight tolerances, a thousand little wiggles with 1lb of force in the right way will allow you to remove what you can’t get off by exerting 1000lbs all at once. Also, the use of heat to separate things: Heating something circular like a bolt in its hole or a shaft in a pulley actually CLOSES the hole while WIDENING the object in the hole. Heating things actually makes them fit TIGHTER. So why does it seem to separate things? Because most of the time the two parts expand and contract at different speeds, which changes the locations of contact between the two parts, thus overcoming the initial force of breaking them loose: that metal to metal, or metal to corrosion to metal bond that forms through high pressure and heat cycles and a long time with the same surfaces in contact. You may find that changing your approach to where you apply impact or heat can have far more effective results. Or, just use a longer lever or a more finely tapered wedge!
Many thanks Ron…having spent 37 years involved in Engineering Issues , within Motorsport, I understand what you are saying, but I don’t agree with your argument relating to a ring and a fastener… I’m sure that you’ll have witnessed the , ‘ball and hoop’ experiment, at Secondary School Science Lessons?
However, I take note and when the new damper is delivered I’ll be taking my MX5 back to the garage… far too old, at seventy-eight, to be grazing knuckles , or laying under cars! I suspect that even with the key and keyway, there has been some micro fretting and ‘friction welding’ taking place, causing the problem.
Robbie Marsh has kindly sent me an email, regarding the removal of MX5 Damper/Pulley Assys; so I’ll print of both and let the fitter read them , before ‘Phase II’!
Many Thanks , once again… I’ll let you know how things go…
I’m not going to contest the ball and the hoop, but I don’t think the same can be applied to shapes of different dimensions. A rod (or bolt) going into a block or more complex ring, I think you’ll find, has a tighter fit when heat and thus expansion is introduced. There are videos on youtube that test the hypothesis and I’m yet to find proof that a bolt hole in a block becomes wider when heated, they shrink! I have seen various techniques of putting one part in the freezer and heating up the other, or just one part in the freezer, when it comes to bearing collars and pistons and all sorts… Maybe your mechanic might have some liquid nitrogen knocking around?
Good luck, anyway. I’m a big believer in hitting things until they let go and I have deformed many an essential part in the process!
