Help! Crank pulley removal – 1998 NB Mk2 1.8 MX5
Discussion
I’m in the middle of a cambelt change on my car and I’ve hit a sticking point in removing the crankshaft.
The car is a 1998 mark 2 on 100,000 miles. The cam belt was changed in 2002 at 55,000 miles but hasn’t been changed since. I’ve got as far as removing the top and middle timing belt covers but I’ve got stuck at removing the crank pulley. Although the car has been garaged for a good proportion of its life the impact of 16 years worth of corrosion seems to be getting the better of me.
I’m really shocked at the amount of corrosion at the front of the engine bay – the area behind the grill seems to really have suffered. The alternator pivot bolt has welded itself to the alternator but I managed to overcome that by removing the manifold bracket and I got enough purchase on the nut at the rear of the alternator to actually shift the whole alternator enough to release the belt. Having overcome that hurdle I have now stalled at the crank pulley stage.
There are 4 bolts on the face of the crank pulley which I have removed. My Haynes manual suggests that once these are removed the crank pulley should be able to be pulled off. Unfortunately, mine isn’t budging. I’ve also seen a few suggestions that the 21mm nut at the front of the crank needs to be removed on some MX5s before the crank pulley will shift. I’ve also tried shift the 21mm nut but I can’t get enough torque on it to shift it (with the car in 5th and somebody on the footbrake). I’ve given everything a liberal soaking with WD40 with the intention of leaving it overnight but I don’t think WD40 alone is going to solve the problem.
So, a couple of questions:
1)Does the 21mm nut need to be removed before the crank pulley can be removed. If so, I think that corrosion is going to prevent me from shifting this simply with just a breaker bar with the car in 5th and a friend braking. So, assuming I need to shift the 21mm bolt to get the pulley off then what’s the next step to get the 21mm bolt off? Apply heat? How?
2)If the 21mm nut doesn’t need to be removed then I think the crank pulley must have welded itself with corrosion to whatever is behind the pulley. I’ll need to pull the crank pulley off somehow. Can anybody give some advice as to how I should be able to pull the pulley off?
Any advice would be appreciated – I really don't want to have to put it all back together again and take it to a garage having got this far.
The car is a 1998 mark 2 on 100,000 miles. The cam belt was changed in 2002 at 55,000 miles but hasn’t been changed since. I’ve got as far as removing the top and middle timing belt covers but I’ve got stuck at removing the crank pulley. Although the car has been garaged for a good proportion of its life the impact of 16 years worth of corrosion seems to be getting the better of me.
I’m really shocked at the amount of corrosion at the front of the engine bay – the area behind the grill seems to really have suffered. The alternator pivot bolt has welded itself to the alternator but I managed to overcome that by removing the manifold bracket and I got enough purchase on the nut at the rear of the alternator to actually shift the whole alternator enough to release the belt. Having overcome that hurdle I have now stalled at the crank pulley stage.
There are 4 bolts on the face of the crank pulley which I have removed. My Haynes manual suggests that once these are removed the crank pulley should be able to be pulled off. Unfortunately, mine isn’t budging. I’ve also seen a few suggestions that the 21mm nut at the front of the crank needs to be removed on some MX5s before the crank pulley will shift. I’ve also tried shift the 21mm nut but I can’t get enough torque on it to shift it (with the car in 5th and somebody on the footbrake). I’ve given everything a liberal soaking with WD40 with the intention of leaving it overnight but I don’t think WD40 alone is going to solve the problem.
So, a couple of questions:
1)Does the 21mm nut need to be removed before the crank pulley can be removed. If so, I think that corrosion is going to prevent me from shifting this simply with just a breaker bar with the car in 5th and a friend braking. So, assuming I need to shift the 21mm bolt to get the pulley off then what’s the next step to get the 21mm bolt off? Apply heat? How?
2)If the 21mm nut doesn’t need to be removed then I think the crank pulley must have welded itself with corrosion to whatever is behind the pulley. I’ll need to pull the crank pulley off somehow. Can anybody give some advice as to how I should be able to pull the pulley off?
Any advice would be appreciated – I really don't want to have to put it all back together again and take it to a garage having got this far.
What you need to hold the crank still is a locking tool:
http://www.autolinkmx5.com/crankshaft-locking-tool...
Or make your own:
http://www.mx5nutz.com/forum/index.php?showtopic=9...
I made my own from an old piece of aluminium plate, so that it bolts to the power steering pump bracket and wont let the crank rotate, but all it needs to do is bolt onto the pulley boss and then hit something to stop the crank turning, even the end banging on the ground is good enough.
However, you need the pulley off to use one of these, and I've no idea about that. On all the mk1s I've had the pulley comes off once you remove the 4 small bolts.
Have you tried a big rubber hammer?
http://www.autolinkmx5.com/crankshaft-locking-tool...
Or make your own:
http://www.mx5nutz.com/forum/index.php?showtopic=9...
I made my own from an old piece of aluminium plate, so that it bolts to the power steering pump bracket and wont let the crank rotate, but all it needs to do is bolt onto the pulley boss and then hit something to stop the crank turning, even the end banging on the ground is good enough.
However, you need the pulley off to use one of these, and I've no idea about that. On all the mk1s I've had the pulley comes off once you remove the 4 small bolts.
Have you tried a big rubber hammer?
Thanks Jim. That 1st link seems to suggest the locking tool works for all mark 2s so I think, as you mention for the mark 1, the pulley should just fall off after the 4 nuts are removed and allow the tool to be used to lock the crank and take the 21mm nut off.
I tried a rubber mallet and it didn't budge. I then got more aggressive and tried tap it outwards with a chisel and it really wasn't budging. If the 21mm nut doesn't come off before the pulley then think I need to find some kind of puller tool that will grab on to the outside rims of the pulley and then push out against the 21mm nut?
I tried a rubber mallet and it didn't budge. I then got more aggressive and tried tap it outwards with a chisel and it really wasn't budging. If the 21mm nut doesn't come off before the pulley then think I need to find some kind of puller tool that will grab on to the outside rims of the pulley and then push out against the 21mm nut?
The pulley will come off but it won't just fall off. It was only held on with 4 small bolts after all.
A pulley remover would be tge correct tool to use but I removed mine using 2 big screwdrivers behind the pulley. Tapping with a mallet might help to get it started but don't hit too hard (obviously).
A pulley remover would be tge correct tool to use but I removed mine using 2 big screwdrivers behind the pulley. Tapping with a mallet might help to get it started but don't hit too hard (obviously).
I'd try squirting penetrating fluid around the 21mm bolt head, as the hole in the pulley is a fairly close fit, and rust builds up between the two. Then try tapping the front of the pulley around the edges. Finally, as Lazza says, 2 big screwdrivers to try to lever it off.
As for the crank bolt, I took the easy option & bought the tool. Made it so easy that it was worth every penny. Make sure you get a good fitting socket though. Also, there's barely enough room to get a socket on, because the front anti-roll bar is a bit too close. I slackened-off the mounting bolts to get a couple of mm extra clearance.
As for the crank bolt, I took the easy option & bought the tool. Made it so easy that it was worth every penny. Make sure you get a good fitting socket though. Also, there's barely enough room to get a socket on, because the front anti-roll bar is a bit too close. I slackened-off the mounting bolts to get a couple of mm extra clearance.
Thanks gents. I don't want to sound negative but I don't think screwdrivers and a light mallet will release this. It was stuck HARD yesterday and I doubt the WD40 overnight will have made enough difference to release it. I've already lowered the ARB and removed the radiator to get some space - well worth doing as both only took a few minutes to remove. The car is at my dad's house so I'm not with the car to try release it now but I'm going to pick up a gear puller like below on the way over there this morning:
http://www.machinemart.co.uk/shop/product/details/...
I'll keep my fingers crossed that this will release it.
This job has made me realise the impact that corrosion has on these jobs. I've also noticed one of the lower timing belt cover bolts has corroded enough that the head disintegrated as soon as the socket put any force on it. I don't think my car was due a timing belt change based on mileage but the job gets MUCH harder the longer the corrosion is left to do it's damage. My car doesn't have an intake grille and I previously considered these as more cosmetic than anything else but judging by the amount of corrosion on the components at the lower front of my engine then I think there is a good argument for a grille in that it will reduce the amount of spray hitting the front of the engine bay? The engine undertray has always been on the car so I think the main source of spray is from the intake. Strangely, my chassis rails are in reasonably good condition compared to the front of the engine.
Thanks for the guidance. I wasn't 100% sure if the 21mm bolt needed to come off first and it's clear it doesn't now. I will let you know how I get on with it.
http://www.machinemart.co.uk/shop/product/details/...
I'll keep my fingers crossed that this will release it.
This job has made me realise the impact that corrosion has on these jobs. I've also noticed one of the lower timing belt cover bolts has corroded enough that the head disintegrated as soon as the socket put any force on it. I don't think my car was due a timing belt change based on mileage but the job gets MUCH harder the longer the corrosion is left to do it's damage. My car doesn't have an intake grille and I previously considered these as more cosmetic than anything else but judging by the amount of corrosion on the components at the lower front of my engine then I think there is a good argument for a grille in that it will reduce the amount of spray hitting the front of the engine bay? The engine undertray has always been on the car so I think the main source of spray is from the intake. Strangely, my chassis rails are in reasonably good condition compared to the front of the engine.
Thanks for the guidance. I wasn't 100% sure if the 21mm bolt needed to come off first and it's clear it doesn't now. I will let you know how I get on with it.
A bit of advice.....don't waste your time with WD40.....it's not a penetrating oil,it's a water displacement fluid(silicone based)
Use a proper product such as Plusgas,freeway,etc and it WILL make a difference.Soak the area with fluid and knock round it with a mallet to break the corrosion and allow the fluid to work it's way through.
Be patient and it will start to move..
Use a proper product such as Plusgas,freeway,etc and it WILL make a difference.Soak the area with fluid and knock round it with a mallet to break the corrosion and allow the fluid to work it's way through.
Be patient and it will start to move..
Hmmm. The gear puller isn't able to get enough purchase on the sides of the pulley wheel to pull it free.
I've tried push some screwdrivers behind the pulley but they just seem to be bending the timing sensor wheel so I don't want to apply too much force there.
I wasn't able to get any freeway or plusgas from halfords. I've sprayed the pulley with some of their "shock and unlock" product and tapped away with a rubber mallet. No luck so far so I've left it to soak for a while now and will return to it later.
Lazza - when you said you used 2 screwdrivers behind the pulley wheel - did you put them between the timing wheel and the engine block or between the rear pulley (alternator) wheel and the timing disc/wheel? Either way I try it seems as though the timing wheel will just deform as it's the softer material and has too much give in it. I could persevere with more force (and push the screwdriver closer to the crank) via that method and straighten the wheel after I suppose.
I've tried push some screwdrivers behind the pulley but they just seem to be bending the timing sensor wheel so I don't want to apply too much force there.
I wasn't able to get any freeway or plusgas from halfords. I've sprayed the pulley with some of their "shock and unlock" product and tapped away with a rubber mallet. No luck so far so I've left it to soak for a while now and will return to it later.
Lazza - when you said you used 2 screwdrivers behind the pulley wheel - did you put them between the timing wheel and the engine block or between the rear pulley (alternator) wheel and the timing disc/wheel? Either way I try it seems as though the timing wheel will just deform as it's the softer material and has too much give in it. I could persevere with more force (and push the screwdriver closer to the crank) via that method and straighten the wheel after I suppose.
Just an update on this. I managed to get the crank pulley off in the end. No matter how much tapping with a mallet, levering with screwdrivers etc it was never going to shift that way. In the end I used the gear puller with the legs held on the back of the timing sensor wheel. It took a lot of pressure against the centre of the crank bolt to break the rust free. I was worried that the timing sensor wheel would deform with the pressure but it seems to have survived ok.
Thanks for all the advice.
Thanks for all the advice.
hi mate ive read your post with interest, a few months after the fact, ,anyway im doing exsactly what you had bother with, striped everything down, took four bolts out and bingo b
d pully wont come off, not wanting to give it the beans but all that should be holding it is the locating pin ,to me the centre bolt isnt holding it on , also found out you have to loosen all pully wheel bolts before you take strain of belts, then its started to rain , something tells me to sell it,
d pully wont come off, not wanting to give it the beans but all that should be holding it is the locating pin ,to me the centre bolt isnt holding it on , also found out you have to loosen all pully wheel bolts before you take strain of belts, then its started to rain , something tells me to sell it, Yep - don't expect this to be a job where a stroke of genius will sort it out. Brute force and ignorance are required. I used a pulley remover tool in the end, the problem with this is it that it either bends the timing wheel slightly ( it straightened out ok) or, if gripped on the rim of the belt wheel it is liable to take a chip out of the wheel before the corrosion releases. It did eventually, and I mean eventually, give though - it took a hell of a lot of force to release it but it was all just to break the corrosion that had virtually welded the thing on.
Having said that everything assembled ok again afterwards, with plenty of copper grease, and it's all been running ok since.
You'll need some patience. Best of luck.
Having said that everything assembled ok again afterwards, with plenty of copper grease, and it's all been running ok since.
You'll need some patience. Best of luck.
hello again, ive just finished the job only thing is i lost a wee screw but left over a big one , duh, anyways tried all to shift that feckin pully but to no avail went to drop underseild to get access to anti roll bar but coulnt get it out the way , so as i was haveing trouble getting socket on crank nut ,i had to file flats for socket fit, sliped bar on put in 5th stood on brakes and hey preston it shifted , what a lenth that bolt was , but looking at the pully i can see how everything was an interferance fit ,and well stuck on so just left it .the pully did come of easily ,changed belt built back up ,well heres a thing the cables that are in a plastic pipe infront of the rocker cover ,well i was putting it on and i noticed wearing ,looked inside to find 2 cables showing thru ,just as well if car had started to play up i dont think myself or einstein would have thought where to look, so after a pint of blood spilt a sore back swallen knuckles i got the job did, a garage near me said he would have done it for a 100 quid aye right ! adios folks forums are not bad .
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