shifting "on the fly"

[OwenD]

Yesterday I went for a drive around the south western cape to show an uncle that is down from the UK some good birding spots.

The route was from cape town, to goudini spa, worcester, villiersdorp, caledon, hermanus, rooiels, muizenberg home.

Twice along this route, coming from Goudini spa to the R43, as well as on the R320 from caledon to hermanus, there were sections of tar dispersed with sections of gravel road.

I thought this was great as I have a mitsu with on the fly shifting (Colt not superselect) from 2h to 4h anything up to 100 km/h. The first time I did this it worked fine (from goudini)

The second time i did this, on the R320 it was fine aswell, but then after changing down to 2h on a short tar section, then trying to change back to 4h there was a grinding noise before engaging. This happened for the remaining times that I had to shift to 4h on the fly.

When we stopped I read the manual incase I was doing something wrong with the clutch or whatever. The manual was pretty vague, it reads something like:

"...shifting from 2H to 4H can be done at speeds below 100km/h, do this while pointing in a straight direction and releasing the accelerator"

A few questions.

1) If I am in 3rd gear, must I leave it in gear while changing from 2H to 4H?
2) Must I put it in neutral?
3) Must I put it in neutral with the clutch in?
4) Must I put it in neutral with the clutch out? (different to 3?)
5) Must I have it in gear with my foot slightly on the accelerator? (as it says WHILE RELEASING THE ACCELERATOR)
6) Or do they mean in gear with the accelerator already released?

How am I supposed to shift on the fly?

My next question is regarding the 'auto locking freewheel hubs'. Upon the first shift from 2H to 4H the hubs automatically lock. This first shift was fine. They only unlock when you reverse a little, which i think i must have done before the R320, therefore the second time was fine as well as it was under similar circumstances to the first attempt.

While shifting from 2H to 4H the third time, then briefly back to 2H, then back to 4H it made a grinding noise. As this was such a short time could this not be because the 'automatic hubs' had not unlocked in the short time that I was in 2H, resulting in the sideshafts and front driveshaft spinning because of the road, at a different speed to my gearbox - so that when I tried to re-engage 4H they were not travelling at the same speed and some grinding occured?

If this is the case (which I doubt as I thought of it) then this system is useless, as that means I could shift on the fly the first time, but between sections of tar and dirt Id have to either stop to change back to 4h the second time, or reverse sometime on the tar, making the whole usefulness redundant.

What could be the other causes of this grinding? I tried the shifting with various ways listed above with similar noises.

Any thoughts?

- Owen

[SimonB]

Owen

As a matter of course when shiftibg between 2H and 4H, both in the Colt and the Pajero, I never do it higher than 80km/h, and do the shift with my foot on the clutch. I did find the Colt couldn't engage properly occasionally. Not that this is right or not (it did work ont he Colt however) but my thinking is if your foot is on the clutch there is no strain on the rest of the transmission while the shifting takes place.