V6 Manual Transmissions

[Fulcrum]

Hi everyone, what a great forum.


I have recently picked up a 2001 NM 3.5 Manual that feels like it has a broken transmission. Makes a horrible metal-on-mental grinding sound when the clutch pedal is released regardless of whether it's in gear or in neutral. It also won't go through the gate into reverse at all. I'm yet to drop the box but it seems like it will be toast.


My question is do I need an NM V6 transmission specifically or is there some interchangeability with the manual boxes between models?

[Roofchop]

Could just be a disintegrated clutch....


Get the gearbox off and take a look...


If the box is toast just go for a V6 one the Diesels probably have different ratios (lower revving)


(Might just be the transfer cases have lower ratios?)



The Manuals are usually reliable unlike the autos.....


How many Kms?
Cheers
Dave

[Roofchop]

With the ignition on but not started select the transfer lever through all four settings you should here a motor whizzing, its on the left side of the box. (and the lights change on the dash.)

If it has failed it could be stuck between two selections .


Worth a try.....

[erad]

I doubt that is is the clutch, because the fact that the noise is there with the clutch in or out tells me the problem lies elsewhere. Since the clutch has to be opened to get the gearbox out, you will soon know. There is a hatch in the bell housing. Open that up and see if there are any loose bits there first.

[nj swb]

With the ignition on but not started select the transfer lever through all four settings you should here a motor whizzing, its on the left side of the box. (and the lights change on the dash.)

If it has failed it could be stuck between two selections .


Worth a try.....

If the transfer is turning with the gear stick in neutral the gearbox has a problem.

I doubt that is is the clutch, because the fact that the noise is there with the clutch in or out tells me the problem lies elsewhere. Since the clutch has to be opened to get the gearbox out, you will soon know. There is a hatch in the bell housing. Open that up and see if there are any loose bits there first.

Certainly worth a try.

Metal on metal grinding noises even in neutral suggest to me that it's either a problem inside the bell housing, or gears are damaged inside the box.

As for replacements (if necessary):

https://www2.pajeroclub.com.au/forum/showthread.php?t=56200

https://www2.pajeroclub.com.au/forum/showthread.php?t=32413

https://www2.pajeroclub.com.au/forum/showthread.php?t=13310

Good luck.

[Fulcrum]

Thanks everybody. I can hear the transfer case solenoid (I assume that's what it is) whirring when moving into 4H, so that seems normal.


Just to clarify, with the engine running and the clutch disengaged (pedal in) there is no sound. Releasing the clutch pedal in any gear including neutral brings back the scraping sound, and the vehicle doesn't move at all.


I heard a story from the local Mitsubishi parts guy about the input side of the gearset being pushed out of alignment so that it no longer connects with the output side, and the scraping sound is the end of the gearset milling away at the inside of the case. He reckoned it was common but I haven't seen a single person on here mention it so it can't be that common!


It's done 315,000 km so could be anything. I'll see if I can find the inspection cover on the bell housing today and have a look inside.

[erad]

If the noise goes away when you push the clutch in, that eliminates the clutch. it must be the gearbox. Unless you are moving it is not the transfer case because when the car is stationary, nothing will be moving in that area. so that points to the gearbox. Probably the input shaft, again because of the car is not moving, the output shaft will be stationary we well. If it is the input shaft, it is most likely the bearing.

[Fulcrum]

If the noise goes away when you push the clutch in, that eliminates the clutch. it must be the gearbox. Unless you are moving it is not the transfer case because when the car is stationary, nothing will be moving in that area. so that points to the gearbox. Probably the input shaft, again because of the car is not moving, the output shaft will be stationary we well. If it is the input shaft, it is most likely the bearing.

Thank you, this was exactly my thinking too.



I am now in the market for a V6 manual box from either a gen3 or gen4. Time to start snooping around the wreckers.

[erad]

I am now in the market for a V6 manual box from either a gen3 or gen4. Time to start snooping around the wreckers.

Be careful to get a gearbox from a petrol engine - the starter motor is on the other side for a diesel.

[nj swb]

Be careful to get a gearbox from a petrol engine - the starter motor is on the other side for a diesel.

The diesel may also have one or more different ratios, but it you don't have much choice, have a close look at the bell-housings - you should be able to bolt the petrol bell-housing to the diesel box, and just live with any difference in the ratios.

[erad]

The diesel has a higher 1st gear ratio (3.952:1, compared to 4.234:1) and a higher 5th gear (0.761:1 against 0.819:1). This is because of the higher torque of the diesel, and its more limited rev range. The effect of this would be to have a higher 1st gear (harder to take off uphill), and also a higher 5th gear (lower revs at cruising speed). Looking at the photos in my Max Elery W/S manual, it seems as if the bell housing can detach from the gearbox, but you would have to check the bolt pattern before buying a diesel box. Cannot comment about the transfer case bolt pattern - they may be different (probably not).

[Fulcrum]

OK guys I have answered the interchangeability question. I couldn't find a V6 transmission (for some reason the ones I did see were 3-4 times the price of any other Pajero trans), so I bought a 3.2 Diesel one. For the sake of science


Guess what? It doesn't fit. While I did measure the transmission up and it all looks identical, including the transfer, what I didn't notice was the length of the bell housing. Once I got mine out and put it next to the diesel one it was clear that the diesel bell housing is 70 mm shorter than the V6 one. Not a big deal since I'm swapping the bell housing over, right? Except of course the input shaft is also 70 mm shorter...


So now we know. The petrol and diesel gearboxes are not interchangeable even though they have the same model code and they appear identical. Oh well, I'll have to keep looking for a proper replacement gearbox!

[psproule]

Split your V6 transfer off the trans and check the splines on the output shaft.

Pat

[Fulcrum]

Split your V6 transfer off the trans and check the splines on the output shaft.

Pat

The selector wont go into reverse at all and I get the same horrible sound in neutral as I get in any of the forward gears, so I'm sure the problem is inside the gearbox.


Playing around with it now that it's out of the car, when I spin the input shaft by hand it occasionally picks up the gears and I can see the outputs spinning. Then it drops it again and I can feel a light clunking as I spin it, like it's right on the edge of engaging. It actually feels like the input and output gearsets are not quite lined up, if that makes sense.