Replacing Rear Propellor Shaft - What IS the Part No.?

[GHendo]

Has anyone replaced their rear drive shaft – it looks to be made from carbon fibre? Mine has a lot of play and when I asked the local MM dealer he gave me two part number … and reckoned you needed both parts … he was just a young kid so maybe he didn’t really know …

MR581617 for $2,779.00 … and …

MR580389 for $1,444 … Holy Crap !!

Anyway, I looked them up on PartSouq and Amayama and can’t really decide which bit is what. PartSouq have a photo of MR580389 and it looks like the complete driveshaft – you can see the part number on a stick, however when you look at MR581617, the diagram appears to be the whole shaft as well – so I’m confused.

If anyone can enlighten me I would appreciate it very much.

Cheers
Geoff

[Lance]

Gooday Geoff.
Just poking about on Google I found this.
It appears MR580389 may be the Front shaft.

https://www.ebay.com/itm/MR580389-Mitsubishi-Shaft-assy-propeller-fr-MR580389-New-Genuine-OEM-Part-/332622573979

This link shows a Rear shaft to be about 850mm, does that sound right ?

https://autoparts.beforward.jp/detail/Transmission---Drivetrain/Propeller-Shafts/PA05081911/

[Roofchop]

Take the shaft to a local specialist and have them make a custom one from steel.


Or just replace the unis if the carbon tube is OK?



Much cheaper option?


Cheers
Dave

[GHendo]

Gooday Geoff.
Just poking about on Google I found this.
It appears MR580389 may be the Front shaft.

https://www.ebay.com/itm/MR580389-Mitsubishi-Shaft-assy-propeller-fr-MR580389-New-Genuine-OEM-Part-/332622573979

This link shows a Rear shaft to be about 850mm, does that sound right ?

https://autoparts.beforward.jp/detai...ts/PA05081911/

Yeah, I think you are right Lance … the more expensive one is the rear one, and yes, the shaft is about 850mm. long.

Take the shaft to a local specialist and have them make a custom one from steel.

Or just replace the unis if the carbon tube is OK?

Much cheaper option?

Cheers
Dave

Hi Dave,

Actually, I’ve been talking to a local specialist and he is investigating if he can make me one from steel. Apparently it’s not as straight forward as ‘normal’ shafts. He said he’d have to check a couple of things and get back to me. Also, it doesn’t appear that the unis can be replaced in the shaft … the manual I have says they are a ‘non-serviceable’ item.

Cheers
Geoff

[spot01]

Being an older vehicle & depending on how long you intend keeping it, have you condsidered the wreckers?

[old Jack]

From the Gen 4 Service Manual;
The rear propeller shaft has CFRP (carbon fibre-reinforced plastic) tube with an impact absorbing mechanism (collapsible) improve safety in the event of an impact.

OJ.

[Roofchop]

It's bizarre that the Pajeros have these carbon prop shafts. How many "safety" issues have occurred in any of the millions of crashes cars/4x4s with steel prop shafts?


Carbon is used these days on super/hyper cars for weight savings...


And then they design them so you can't replace the unis.....Very strange indeed.


Cheers
Dave

[spot01]

It's bizarre that the Pajeros have these carbon prop shafts. How many "safety" issues have occurred in any of the millions of crashes cars/4x4s with steel prop shafts?


Carbon is used these days on super/hyper cars for weight savings...


And then they design them so you can't replace the unis.....Very strange indeed.


Cheers
Dave

The cars have only been crash tested with the carbon props, not with steel, so the manufacturer is never going to say steel is OK.


They use aluminium for the bonnet to save weight, even though it costs more, so perhaps carbon was used to save weight?
Or it might be to solve a vibration or noise issue?
Certainly not to save manufacturing cost!

[k100dennis]

I suspect that (as 'ol Jack has touched on) the carbon fibre shaft is an integral part of the monocoque body design. It would be designed to behave in a certain way in a rear end collision whereby the crumple zones come into effect and the rear differential housing moves forward as it's connected to the underbody.
The debate about whether or not there have been many crashes where it came into effect is irrelevant really, as the consequences of a steel tailshaft penetrating the floor are potentially horrendous. No doubt a steel tail shaft and serviceable uni joints can easily be made and fitted but user beware.

[Lance]

Apart from the Pajero, what other vehicles use a carbon fibre shaft, and why ?

Why don't we hear many reports of the pros & cons of carbon fibre over steel ?

Is CF a mandatory fitment anywhere ?

Curiosity has been sparked

[old Jack]

In a body on chassis design the tailshaft can vertical pivot between the gearbox and diff as the diff travels with the suspension. The tailshaft slides into the rear of the gearbox and can move in and out as required. With the Gen and IRS both the gearbox and diffs are mounted to to body via subframes so the distance between them is constant until there is an impact that compresses the length of the floorpan as it absorbs the impact forces. Fitting a solid tailshaft would reduce the ability for the floorpan to absorb impact forces so these forces will go elsewhere. In real life how much this would matter I do not know? I would have thought a low km second hand composite tailshaft would be a better choice than a new solid steel unit.

OJ.

[Roofchop]

Good points...


But....How many IRS monocoque rear wheel drive cars are there out in the world?


BMWs, Mercs, most modern Yank tanks, Even Volvos!



None with carbon tail shafts apart from super/hyper cars.



All crash tested with steel shafts.


Mitsubishi did it for a reason but why.....?$$$$$$


Cheers
Dave

[old Jack]

Hi Dave,

Mitsubishi state in the Workshop Manual, the composite tailshaft is for safety, I have read that they tend to reduce noise transmission into the cabin.
As Spot 01 pointed out, It cannot be cost reduction since they are much more expensive than steel tailshafts. Weight reduction is a possibility since Mitsubishi also used an aluminium bonnet.
Will we every know the complete truth?

OJ.

[GHendo]

Well, my local driveshaft bloke said there are quite a few vehicles now with carbon fibre tail shafts and some use aluminium as well. He has never done a Pajero before and doesn’t seem keen to try and make me a steel one.

However, I contacted Driveline Services Australia at Acacia Ridge in Brisbane, and they said they’d done a few of them – total cost in around $800 – compare that with $2,799 for the OEM one.

The thing that annoys me about this is Mitsubishi make the replacement part so expensive that owners look for alternatives. Why would I want to give them an extra $2,000 when every other vehicle I’ve ever owned had a steel driveshaft? If it IS a safety feature, surely they should encourage us to use their part instead of just thinking about the monetary issue – as if !

I did intend making enquiries from wreckers, however with something like this you’re not going to know what you’ll end up with. The carbon shafts are easily damaged, during and after being removed from the vehicle, and I could be spending a few hundred dollars towards something I’m going to have to replace AGAIN in a short period of time – ie. there is no real way of knowing how many kilometres the second hand shaft has done.

Cheers
Geoff

[spot01]

Well, my local driveshaft bloke said there are quite a few vehicles now with carbon fibre tail shafts and some use aluminium as well. He has never done a Pajero before and doesn’t seem keen to try and make me a steel one.

However, I contacted Driveline Services Australia at Acacia Ridge in Brisbane, and they said they’d done a few of them – total cost in around $800 – compare that with $2,799 for the OEM one.

The thing that annoys me about this is Mitsubishi make the replacement part so expensive that owners look for alternatives. Why would I want to give them an extra $2,000 when every other vehicle I’ve ever owned had a steel driveshaft? If it IS a safety feature, surely they should encourage us to use their part instead of just thinking about the monetary issue – as if !

I did intend making enquiries from wreckers, however with something like this you’re not going to know what you’ll end up with. The carbon shafts are easily damaged, during and after being removed from the vehicle, and I could be spending a few hundred dollars towards something I’m going to have to replace AGAIN in a short period of time – ie. there is no real way of knowing how many kilometres the second hand shaft has done.

Cheers
Geoff

I suspect the MMAL cost to some extent reflects the high cost of this material/component - they don't spend extra money on new car bits unless they have a good reason.


Re wreckers, try to find a good Mitsi specialist, like Eddy Wreckers @ Gillman here in Adelaide, as they know their stuff & will stand by it if something goes wrong, eg, a mate here had them install a used diesel engine in his NP. After a while, he wasn't totally happy with how it was running (just didn't feel quite right), Eddy agreed & replaced the engine, no dramas - great service. If you find a low km, non major accident one, I would think it will be fine. Ideally one still on the car would be best, although joint wear would be a good guide.