Diesel Knock Update

[Martin]

Changed oil to penrite HPR 15w 50 and knock disappeared however it looks as if it may have been a prelude to a larger problem. Last friday while on the freeway in Sydney the pajero came to a grinding halt with a loud scraping noise coming from the clutch area, later when at workshop it was suspected that a spring may have dislodged from the clutch plate however this was not to be, the pin holding the clutch & pressure plate in had seized and could not be removed, hrs later and with much persistence & (swearing) the mechanic managed to remove the whole assembly with gear box in one piece.
What was found was that there was rust or corrosion on the pressure plate & pin that held everything together, Oil had been leaking into the housing from a rear engine seal. This can be checked by removing the rubber inspection cover on the clutch & pressure plate housing & putting your finger in & finding a thick greasy mix of oil & dust. The next discovery was that the flywheel has a bearing thats like (we think) a one way clutch or bearing, were not quite sure because its totally cactus and has 2 large rivets holding it in place hopefully we can acquire the bearing only and not the whole assembly also it looks as if the clutch & pressure plate will need to be replaced as thy have been cooked with the aid of oil leaking in. This after the vehicle was in to a mitsui dealer for a recall to re direct the a/c drain from top of gear box to the side. The ramifactions if not attended to may be total malfunction of clutch.
Has anyone come across this, coments would be appreciated especially regarding the bearing in the flywheel which seems to be odd especially if it doesn,t have a long life, Vehicle k's 244000 however this problem could have been going on for a while and the bearing in the flywheel is not easy to diagnose.

[vinceb]

Hi Martin.
I had a clutch problem with my NP DID. At approx 60000km I had to replace the clutch(only a few weeks before I had the a/c drain pipe fixed under warranty).At the time of replacement the mechanic said that the oressure plate looked like it had been for a long swim as the friction material had completely changed colour. The pressure plate & throw bearing were ok.
I lodged a complaint with MMA & after 2 months received a reply stating they would not cover the replacement clutch.
Pretty damn slack on MMA's behalf. So much for their great advertising campaign.
Good luck.
Vince

[marquis]

I changed to DELO 400 Multigrade - have not looked back in engine performance or engine noise levels (much lower engine noise than MM's service depot oils - aka castrol is typical).

[Martin]

Vince

Is the throw bearing on the pressure plate or on the flywheel as the bearing that has packed it in is on the flywheel i think the mechanic destroyed another bearing as to remove the pressure plate.

Cheers

[brett]

Martin, what model are you running? at 244K I guess it's not a NP, maybe NM
Don't quite follow your description of the fault, particularly the bit with the pin holding the pressure plate and clutch plate, can you explain this a bit more.
While I haven't pulled apart a NM/NP clutch the only difference from a standard clutch setup as far as I know is the pressure plate is a pull setup instead of the standard push. So you have a throwout bearing in a fork that is attached to the clutch lever and this pushes on the diaphragm of the pressure plate to disengage the clutch, this bearing generally will outlast the clutch plate but is replaced with a new clutch. The clutch plate just sits on a spline on the input shaft to the gearbox, it's in no way attached to the pressure plate which is bolted to the flywheel. Then the tip of the input shaft of the gearbox sits in a bearing in the end of the crankshaft, generally it's just a bronze bush and very rarely wears out.

[Martin]

Brett

Yeh, sorry my technical knowledge is very limited i'll have more detail on monday however the bearing that went is on the flywheel & we presume a one way bearing the mechanic thinks it may have something to do with slowing the vehicle down when coasting down a hill, (maybe). i haven't got a manual to look it up but he has worked on older models and hasn't come across it thought it a bit unusual especially with a short life span. Will investigate further and be in touch with mitsu to try and find out why it would give way so early especially when the wear on the clutch & pressure plate was minimal & would have got another 100000 ks before replacement, also the seal on the back of the engine is gone which we think has been gone for a while.

[Martin]

Flywheel

Continuing on we have more info, the problem lies with what is referred to in the manual as the flywheel assembly which has a one way bearing in the centre & is there to stop the vehicle running away down the a steep descent, the bearing also stops the rear wheels locking up when you take your foot off the accelerator because of the torque in this particular motor which we all know has plenty of power. Th e thing i'm a bit peeved is that it should last a lot longer and is hard to pick if you don't know what to look for, for all we know it could have been going for a while but every body i took it to including Mitsu had know idea.
The biggest sting is the price for the assembly, $1500 (just the part) and they won't sell the bearing separate as per usual. There's nothing wrong with the rest of the flywheel. PS check the inspection cover over the clutch & pressure plate for oil leaking in from the main seal as the seal is only $70 or there about.

[psproule]

Continuing on we have more info, the problem lies with what is referred to in the manual as the flywheel assembly which has a one way bearing in the centre & is there to stop the vehicle running away down the a steep descent, the bearing also stops the rear wheels locking up when you take your foot off the accelerator because of the torque in this particular motor which we all know has plenty of power.

We are talking about a manual aren't we? Because that doesn't make any sense. If that were the case the motor would return to idle at coast. I have had one of these apart and have changed a clutch. Besides being a pull rather than a push clutch (a bit tricky to disengage the linkage when you remove the box) they look like a normal albeit large clutch,l and definitely do not have a one way bearing you speak of. I have an old one in the workshop somewhere.

Pat

[Martin]

Flywheel

Yeh, I haven't explained very well to remove the clutch etc there is a large pin that has to be removed which in turn allows the you to remove the clutch & pressure plate, I'm not sure of the exact procedure however the one in my vehicle was seized, the pressure plate was covered in rust & this was probably due to the a/c drain on top of the gear box which mitsu had re directed on recall. (However i don't think they would ever admit to it as that would not be good corporate policy), The main problem we came across was the flywheel and yes it is not a one way bearing as first thought it is actually called a Dual mass flywheel assembly, (I have a photo & will post) the bearing in the centre is like some sort of damper the one in mine was shot that's why we couldn't work out what it was doing as the flywheel spun on it making a scraping noise. The mechanic was not sure as it is a part that you would expect to last a lot longer as the flywheel, clutch & pressure plate had plenty of life left in them. When we finish repairing we will drill out rivets and have a look at what has happened.
PS sorry about my lack of mechanical knowledge.

Cheers

[psproule]

Ok - makes sense now. I think the dual mass flywheel may only be on the DID - don't remember seeing the assembly on my petrol when we had the transmission out. I know that they are prone to failing on some of the Patrols - the 2.8D's I think, and they cost a bomb to replace. There is an after market non-dual mass alternative for them. DOubt if you will find anything but a genuine one for a DID though. Be interested to hear how you get on.

Out of interest - I have been contacted for a "recall" on my DID to fix the aircon drain tube. Only took 7 years of the model to do it!

[Martin]

A/C Drain Tube

I received the recall about 3 mths ago and all they do is re direct down the side of the gearbox, I have a 2002 NM DID & have had it since new & as i mentioned in prev post when the pressure plate was removed it was covered in rust & various other parts had seized so I don't know how as you'd think that the gearbox etc would be fairly well sealed the only thing i could think of was that with water dripping down the side of the case that it seeped into the rubber inspection cover.

[Martin]

Pressure plate Rust

This is the Pressure plate & clutch From a 2002 NM with 244000ks
Note the Rust on the casing