Improving the MN gearbox shift feel & operation.

[alan_blue]

Do you sample the triton oil is that what you mean mate?

[Kegsy]

Yeah.

I take samples from my triton and send them to the guys who also do the analysis for our heavy mobile plant.

[sierra]

Yeah I agree with not changing it regularly as there is no need once you have the correct oil

I throw in oil samples for testing when I do all the mobile heavy plant at my work. Oil analysis has shown a steep degradation in oil quality after 15,000kms...

That's very interesting, especially considering the service oil change kms and the latest trend of no transmission oil change for the life of the vehicle[transmission]
Do expensive full synthetic gearbox oils also break down that fast?

[alan_blue]

How many k's have you assessed the triton for? It will get worse over time obviously and I think you can look a little too deep at times. When you do the samples is there a trend of what metals are found in the oil thus can then see what parts are wearing most?

[Kegsy]

It's not the oil breaking down sierra. It's the contamination levels in the oil. The oil itself is capable of much longer life providing everything is A OK in the GB. But for some reason these GBs seem to have a weakness with syncros.

The contamination levels rise extremely fast in these gearboxes (from my experience). This may not be the case for everyone, but both my gearboxes have shown similar results. The current box being slightly worse than the previous.

I do samples where I can, not as often as I would like to however as I only do them when it aligns with another piece of gear onsite as its quite expensive to do regularly.

Contamination points to bearing failure in both instances. And other ferrous substances could be a number of things.

Chemical makeup of the oil seems fairly solid and consistent, even the stuff the dealership uses.

Either way, people with the older mn gearboxes should monitor their oil closely, the boxes with the 'new' parts I'm not too sure how they fair...

[srb]

Interesting stuff Kegsy. Every time I've changed my oil it has heaps of metal in it.. Even after 5k it wasn't so good. I did this just to see how quickly the oil changed from good to bad. I have done 32k in total on this GB and it's still works smoothly but I wonder how long it stays like it. Glad we have 10 year warranty ay.

[sierra]

That's strange because I've changed my oil about 4 or 5 times trying to shut the rollover/rumble up and have only found metal contamination in it once. It looked like brass.
The last time I changed it the oil was spotless and must have been in there for 10,000km. I remember being relieved and wondering why it was clean again?

I wonder if it's the oil? Apart from this one, the others have been mineral or semi synthetic and the last one was the latter with this being full synthetic. If I was keeping it I would be tempted to drop the oil or some of it, to check but I'll be selling it soon. I picked up my new car on Xmas Eve.

[Kegsy]

Agree with ya there Steve.

Plenty of filings in the oil, a little is to be expected in a manual trans but I think its a little excessive. Oil samples seem to back this up showing elevated levels of ferrous materials.

Also just the general look of the oil tends to be putrid, it should still look fairly clean after such a short period.

My next mod will be a magnetic drain plug I think.

[whome]

Hi Kegsy,

You mentioned -

"Either way, people with the older mn gearboxes should monitor their oil closely, the boxes with the 'new' parts I'm not too sure how they fair..."

I assume by this that there have been changes to the MN gearbox which might lessen the oil contamination issues? Can you please fill us in on the changes, when they were introduced and maybe what problems they rectified.

Many thanks..

[Kegsy]

Apparently with the MN gearboxes mitsu realised there was a problem with the syncros as so many people were having troubles with them. Especially 2nd and 3rd selection.

Any gearbox that goes back for warranty is now being rebuilt with different parts to rectify these issues.

As for what these internals are, there part numbers etc I have no idea. They have been using these new parts for a few months now according to my dealer, they should rectify problems with gear selection caused by failed syncros and slides.

Unsure if this will help with the contamination issues, but I dare say if the syncros are running as they should everything should be OK from then.

One of the mitsu tech guys here would know more about that side of it, its been a fairly common issue. Maybe lee-thal or Chaser.


Anyway, sort of gone off on a tangent now. The better quality full syn oil definitely did help with better shift feel.

[alan_blue]

hue guys I have booked mine in at mitsi to take a look at the poor feel and hard to engage 2nd when cold. Its in next thursday and i will let you know what happens. FYI its a 2012 glxr

[alan_blue]

Agree with ya there Steve.

Plenty of filings in the oil, a little is to be expected in a manual trans but I think its a little excessive. Oil samples seem to back this up showing elevated levels of ferrous materials.

Also just the general look of the oil tends to be putrid, it should still look fairly clean after such a short period.

My next mod will be a magnetic drain plug I think.

i think the mag plug will be an excellent idea, im suprised it doesnt have one already?

[srb]

Yeah I'd do this if I could find one? Where do you get magnetic plugs from?

[Longranger1]

I think I'll just convert the standard drain plug. Blind drill so as to fit a little neodymium magnet (from Jaycar) and epoxy it in. Should do the trick.

[Longranger1]

I think I'll just convert the standard drain plug. Blind drill so as to fit a little neodymium magnet (from Jaycar) and epoxy it in. Should do the trick.

[alan_blue]

You wouldn't want it falling off lol

[aids84]

There is a magnet inside the gearbox near the reverse idler shaft, beats me why they just didn't use a magnetic drain plug....

[alan_blue]

You can buy them online I found a company selling 18mm ones. Does anyone know what size ours is before I think about removing it

[Longranger1]

Why put a magnet in a place that is inaccessible? Doesn't make a lot of sense to me either.

[biggibbo]

Theres heaps on ebay, just need the bolt size and thread pitch, anyone???

[pyr081]

The transfer and diff drain plugs are magnetic and both fit the gear box.
My local dealer had a front diff drain plug in stock (was less than $20) when I changed all my oils so I got it for my gear box. I would have preferred a transfer plug as the magnet is much larger.

[Kegsy]

winning.

Thanks for that

[srb]

Awesome! I have a spare diff here to use!

[alan_blue]

sweet well may order a transfer case plug then, good work

[Brayden's dad]

Maybe if there's enough of us, we could make it a group buy and get a discount?

Maybe one of the site sponsors might be interested in trying to swing something?

I'd be up for a magnetic plug.

Regards,
Troy