3.15 gears are in & testing!!

[Ian Sharpe]

Ok guys,

Finally got the Paj back from the shop with the new gears installed.

You can certainly I feel the difference!.

In fact any lower & i'd say they would be too low (for me anyway).

One steep hill on my place which is usually a 'foot on the brake' job til you get to the bottom, is now a nice slow saunter down without any pedal at all.

They are no noisier than the standard gears at low speeds but in 4WD Low & 3rd gear (auto) there is a bit of gear noise almost similar to my old Landie. That may be because of the deep gears or Perhaps its could be because they are new, I dont know. ANyway its not much of a problem .

I'll give them a better work out on the weekend .

Problems that you need to be aware of.

The idler gear supplied would not take the snap ring because the bearing sat too high.In other words the recess was about .5mm out .

Unfortunately they tried to force the bearing on more & stuffed it. Result new bearing $110 bucks!!!. I have supplied Frank with the specs of the bearing & he will check against the one in the case he has.

If any of you guys get these gears note that you must NOT force the bearing to make the snap ring fit otherwise you'll be up for another bearing & the MF's arent cheap!.

There is a spacer that comes with the bearing & has to be machined .5 mm off that to get the snap ring on. That is providing the snap ring wont go on.

The bearing is NTN part number NUP2206ET2XU. It is 19.5mm thick.

When they ground out the bit to fit the low gear, they decided that too much crap got into everything so they dismantled the case to clean it out. I'm not sure if that was necessary but thats what they did anyway.

The case comes out without taking the tranny out.

The install cost $610 (inc oil & parts) without the cost of the bearing.

As far as I am concerned I wasnt prepared to do the job myself, so thats my price for not having any headaches. Others may wish to install themselves.

Just for info :

My low has gone from 25:1 to 41:1

Second low is now what old first low used to be!

You guys with manuals will now have a 57:1 low gear!

Thats pretty serious.

Anyway the long wait is over (only about 2 years)

Ask as many questions as you like

cheers

[Bitsamissin]

Good stuff Ian keep us updated on the testing.
We think Mitsu used different thickness spacers for one of those idler gear bearings (for assembly purposes) so it will be a matter of shaving a bit off if necesary during an install (no biggy - just something to be aware of).
The snap ring grooves are identical to the standard gears (we checked this) so the variance will be in the spacer.
We found this on some of the other t/cases we have assembled and when we checked with Mitsu they had all different sized snap ring and spacer thicknesses available. So there must have been quite a large tolerance built in during manufacture and any variance was taken up with different thickness spacers (and snap rings).

PS - don't you have 4.90 diffs ??
I would make low range 1st at 43:1 with those or 41:1 with 4.636 diffs.
The gears will need to run in a little and should quieten down a bit don't forget to change the t/case oil after about 1000K's.

Frank.

[Ian Sharpe]

Ok Frank,

I did have 4.90 gears in my NK, I got rid of that some time ago & now have the NL. Standard diffs now. I kept my rear locker though, just had to get the cw&p swapped back over on both vehicles. Pain in the ass!.


IMO the 4.636 to 4.90 gear swap was NOT a good exercise. I really only did that to get a bit of 'go' back as that Paj was on lpg.

The NL has a far more effective torque range. I could tell the moment I test drove it.

cheers

[NJV6]

IMO the 4.636 to 4.90 gear swap was NOT a good exercise.

Not a good exercise in what respect? More of a pain in the arse than the benefits?

[Bitsamissin]

Some more imfo : -

Yeah the difference is in that spacer and not the bearing.
The idler gear rear bearing (one with spacer & snap ring) is only the one Mitsu part no, so in other words they only used the one bearing size.
The main difference is in the spacer for that rear bearing there are 5 different thicknesses available :-
1.77mm = MB896728
1.91mm = MB896729
2.05mm = MB896730
2.19mm = MB896731
2.33mm = MB896732
There are also 2 snap ring thicknesses available :-
1.48mm = MB919176
1.62mm = MB919177
So you can see how much the manufacturing tolerances can be out so they make up any variances with different sized spacers and snap rings.

[Ian Sharpe]

Not a good exercise in the fact that I experienced little gain for lots of $$$.

When you do the sums its only about a 5% difference in ratios.

[Ian Sharpe]

Good work Frank,

so its really a suck it & see situation as to what you might have in your transfer case.

Nothing is easy is it.
But we live & learn.

I mnight get a price on that bearing tomorrw & see how much it retails for.

[vpaj]

Waiting for your findings during the weekend

[99Montero]

Waiting for your findings during the weekend

Sounds like some more added work. Will there be a kit that includes all the hardware, unless its a simple fix that anyone can buy? Just curious. Hopefully my piggy bank is ready! I'm gettin all excited

Angelo

[Ian Sharpe]

If it wasnt for the problem with the spacer , this would have been a relatively straight forward job.

The tranny doesnt need to come out, the ATF fluid doesnt need to be drained.

The only problem was the spacers. Now that we know Mitsu used about 6 different thickness spacers, we can be more prepared.

I dont think there is any way of knowing what spacers you have on your case until its apart & checked (unless the Mitsu dealer can tell by your VIN).

If your spacer is too thick, just get it machined or replaced with one of the above that takes up the gap. If the spacers is too thin well then I guess just add another or machine 2 until you get the required thickness.

No sure if having any movement in that bearing up the shaft would be a problem though. Frank would know.

Apart from that its really straight forward (providing of course you have the right gear). Thats another reason I opted for a specialist to do the job.

But as I said earlier, this changes the way the Paj drives in 4WDLo (auto) so be prepared for a whole different feel.

cheers

[Ian Sharpe]

OK , i've had a bit of a play around my property this morning with the new gears.

As I said before these gears now change the way the Paj drives in 4wd Lo.

But I certainly think that there is heaps more control now than before , especially when you really do want to go slow.

BY using the HOLD mode of the auto , you can bypass 1st (which is now seriously low) & have a much smoother ride as the change from first to second comes on pretty strong now. I will just use 1st now for serious slow stuff. My 2nd gear is now about what old 1st was, so thats OK as far as I am concerned,

Also there is no hope of getting past 40kph. I tried & it was screamin its head off at 4000rpm!.

All considering I am happy with the outcome.

cheers

[DougH]

Hey Frank.

When do you think these will be available for sale? I am going to start looking for a second hand tcase so I can build it and limit my down time.

[99Montero]

Any news on the new gears? And also price range?

Angelo

[DougH]

Check the wire Angelo.