Mitsubishi Pajero V6 – crankshaft pulley issues
Here at Autofix we have recieved a number of questions relating to the crankshaft pulley bolt working it’s way loose on a number of V6 Pajero’s and I though it worthwhile to add my two cents into the subject. This seems to be a very common problem and due to the damage that can be done to crankshaft, owners contemplating changing the timing belt themselves need to be aware of this issue.
Nine out of ten times when this has happened a timing belt change has not long been done which leads you to think that the crankshaft pulley bolt may not have been tightened adequately which is more than likely the case, however I know of a few occasions where the bolt has worked it’s way out during normal use.
I think this highlights the need for regular checks of the crankshaft pulley bolt torque, perhaps every six months or so would be a good idea. Although checking the bolt torque without the right tools is not a simple job, a replacement crankshaft is definately more involved and more expensive!
So how do we go about tightening or checking the crankshaft pulley bolt torque? The Mitsubishi workshop manual lists a special tool used for preventing the engine from turning and if you have a look at the picture I think anyone with reasonable fabricating skills could knock one of these up and I believe this to be the easiest method for doing this job. There are a couple of other ways to do this and I will cover these when I have access to a Pajero so I can include pics with the articles.
NOTE: The torque value required for the bolt is listed in the workshop manual as 177-186Nm. Before removing the pulley bolt please be sure that you either have or have access to a Torque Wrench that can be adjusted that high. If you have completely removed the bolt be sure to use Locktight on the thread before refitting.
I’ve got my hands on a ’99 model Challenger that has the 3.0 24 Valve engine and have made up a copy of the Mitsubishi tool that I think could be adapted to all models of the Mitsubishi V6. Check it out here.
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Hi, Am thinking of refitting the crank shaft pully as its gone loose.
Will need the right tools so how can I get my hands on any of these tools?
Are they expensive?
Which way is it to be rotated off then back on?
R
how much torque is required for replacing the cramkshaft pulley
Hi Joe,
The bolt that secures the crankshaft pulley should be tightened to a torque of 180 Newton Metres ( 133 Foot/Pounds ) to avoid the bolt coming loose during normal operation.
hi,my pully bolt came loose while on a long trip thankfully it was on my way home,unfortunatly on ckecking it later i found that the key was distroyed,do you know where i can get a replacement,brian
Brian,
I believe you will only find a replacement crankshaft key at a Mitsubishi dealership. Not an expensive item from memory.
Regards,
Craig
cheers craig for info,cheers brian.
You’re welcome sir.
hi cgaig if your about,the key on the crank has snaped of and a piece is left inside the timeming sprocket,any ideas as to how i can get it out,i presume this key serves both the sprocket and the pully.
That’s not a good situation Brian. You are right in thinking that the key serves both the timing belt sprocket and crankshaft pulley and given that I think the timing belt and sprocket will have to come off to retrieve what is left of the key.
Is there any part of the key left protruding from the sprocket?
Regards,
Craig
hi craig,have actually done the motor now,,it might be worth you mentioning to outhers that if the pully comes loos that this is the sort of prob that can result and if they are not machanicly minded will cost a pretty penny,my machanic mate helped me at a much reduced rate,with the pully and his help it still cost over two hundred,i wouldnt want to pay full rate,the tool you mentioned is a great idea it works perfect,thank you for your imput,vrey gratefull,brian.
It is good to hear that you got it all sorted Brian. You’re dead right about the cost involved in such a repair if you’re not mechanically minded and had to pay full rates, a lot of money to repair what I consider to be a design fault in the first place.
The area of the balancer that is in contact with the crankshaft is way too small for the mass of the balancer and where the belts run is too far forward from the snout of the crankshaft which puts an unnecessary amount of pressure on the retaining bolt leading to bolt failures or the internal thread of the crankshaft wearing resulting in the bolt loosening. In my opinion at least!
Anyway, good to hear you got it sorted and I’m glad the tool worked well for you.
Regards,
Craig
Hi all,
I’m hoping that someone may be able to help me get an idea of what is going on with my Pajero. I got an old ’96 Pajero about 2 months ago. Had a hose from the manifold go and had this replaced along wth a couple of heater hoses that are fitted behind the engine. A day later their was water pouring out underneath, after $1,200.00+ bucks it turned out to be the plenum chamber gasket ( they also replaced the water pump, inlet manifold gaskets and o-ring seals). They re-fitted the timing belt and manifold. My wife picked up the car it and it was running like a dog with no power and making a hell of a noise with a knocking from the engine compartment. Left it with the mechanics and they didn’t look at it so I don’t know their thoughts, and I don’t trust them (as I think I’ve been taken for a ride). My concern is that with the way it is running, it seems like a head gasket, but I don’t want to face that reality. Just wondering, if the tinming belt was done, is it possible that it is the balancer that is making it mistime and leave it with no power? Can this also cause a knock from the engine.
I’m a complete novice with these cars, and just want to get an idea before taking it to someone to try and get sorted.
Thanks heaps for the site and being able to ask what may be dumb questions.
Cheers,
Wayne
Hi Craig,
Thanks for your response, gave me peace of mind that this was probably more of timing issue than something more terminal.
Ended up getting the car and taking it to a mate of mine to have a quick look at for a second opinion (Oddly enough, when I picked up the car, I didn’t see the owner, some guy gave me the keys without asking who I was, I didn’t get a call asking why I had picked it up, or even to confirm that it was me who picked it up, anybody could have driven away in it.). The guy I took it to said that the injectors were not seated properly, causing it to run so badly. I’m now off to the original mechanic to leave it agin and get him to fix it for nothing, seeing as how it was running perfectly before taking it to him. If he plays ball, all well and good, if he doesn’t then I guess it’s off to the dept of fair trade for compensation for the cost it will take to get it running again.
Awyway, had to vent that as this is driving me crazy. Thanks for your thoughts from the other day, really appreciate it. Very thankful for guys like you who run these forums and take time out to help out those of us less knowledgable in these matters.
Cheers,
Wayne
hi all , new to this and not long had my 92 petrol pajero , all was great for the first few weeks til it decided to give me some trouble, the pulley that the fan is attached to ( not really mechanicly minded lol ) is that a major job to fix as i started it up yesterday and it is wobbling like crazy .. help?? lol , any comments would be a great help thanks shaneo
Could be worse. I had the same bolt sheer off and drop into the bash plate below. It took me 10 days and god knows how many broken drill bits to get the shaft out. In the end i had to retap a 14mm x 1.25thread into the shaft then put heaps of locktight on the thread. The problem i could find was the key vibrates and allows the harmonic balance to chop out the key then bang off the head comes.
Do yourselves a favour and YES check the tension of the crankshaft bolt.
I have had two balancers come loose on my 1999 Challenger, also the previos owner had at least 1 come loose as my first was an aftermarket one. Is going in for cam seals next month so will be drilling a second roll pin hole in the balancer and cog to secure the balancer I hope this will stop any movement so the bolt wont come loose. A very poor design by mitsubishi on such a lovely 4×4.
My 93 has followed the same faith.
.
It started the other day with a terrible sound and lose of power steering,i only have it 3weeks and the garage warranty has gone as i had done 1000kms+,extended warranty won’t pay more than $1000,not happy,was loving my Pajero before this and had thought i had got a good one
The garage reckons $1500 on labour plus the $1200 for crank repair,it’s crazy,from perfect to shit in 2 seconds.
Will check on if the belt was done.
I lost the A/C belt a week before this happenned,not sure if that has anything to do with it.