Gen4 - Selecting 4WD

facade wrote: The reason to dip the clutch is because if the back wheels are spinning at 60mph but the fronts aren't moving and you snatch 4x4, likely the teeth will come off something.
Dipping the clutch helps the back wheels roll at the same speed as the front, but the stationary diff and propshaft still have to accelerate to road speed on the synchro cone between the front output shaft and the main output shaft in the transfer, so I'd keep the speed down rather than go for it at 60. :ohmy:

Im not sure about this. So accelerating slightly is a big no no in this case then, as this will be giving the rear wheels and prop etc more of a challenge for the front to sync too??

I think you are all overthinking this. If you are driving down a regular road and think you need to be in 4wd then push the lever and will sort itself out. If you are stuck in deep mud with the rear wheels spinning at 30mph and the front wheels stationary then wait for the wheels to stop spinning before selecting 4wd. I've done it at 60mph on the road with no issues (gen 3 manual transfer case) but the lever is slightly stiffer at speed because, as Facade points out, the syncro has to get the front driveline up to speed before it can mesh into gear.

The only time I've ever made it bang was messing around in the mud, 2wd low, sliding backwards with the wheels spinning forwards and then flicking my 2 low switch into 4wd, making the hubs engage the stationary front wheels to the rapidly rotating front driveshafts. But that's not a situation that's normal or easy to repeat!

Andy2640 wrote:
Im not sure about this. So accelerating slightly is a big no no in this case then, as this will be giving the rear wheels and prop etc more of a challenge for the front to sync too??

Only significant if the back wheels are spinning. I think the manual is translated wrong. The average non-mechanically sympathetic driver interprets all controls as fully on or fully off, so lifting up slightly would be a better instruction than stamping down.


If you aren't frantically spinning the wheels the system will cope. If you want it to last longer, keep the speed down. Dippng the clutch is easy on a manual, you treat is as a gearchange.

So I read the manual for my new Jimny last night.

Shifting from 2H to 4H is essentially shift on the fly rated to 60mph. To do this you need the wheels point straight (because the would be spinning at different speeds left to right if you are turning) and have the front and rear wheels moving at the same speed. Ie not wheel spinning. Revs are required for the vacuum operation of the front hubs. But no need to use the clutch or shift into neutral.

Obviously shifting at low speed or stationary is less risky of accidentally shocking the system, there is less potential energy involved. And trying not to shift when wheelspinning.

Shifting to low is different because you are actually swapping ratios in the transfer box. For this you’ll want to be in neutral and/or put your foot on the clutch. Stationary is probably best, but suspect rolling at walking pace and it’ll probably still be ok.

300bhpton wrote: So I read the manual for my new Jimny last night.

Shifting from 2H to 4H is essentially shift on the fly rated to 60mph. To do this you need the wheels point straight (because the would be spinning at different speeds left to right if you are turning) and have the front and rear wheels moving at the same speed. Ie not wheel spinning. Revs are required for the vacuum operation of the front hubs. But no need to use the clutch or shift into neutral.

Obviously shifting at low speed or stationary is less risky of accidentally shocking the system, there is less potential energy involved. And trying not to shift when wheelspinning.

Shifting to low is different because you are actually swapping ratios in the transfer box. For this you’ll want to be in neutral and/or put your foot on the clutch. Stationary is probably best, but suspect rolling at walking pace and it’ll probably still be ok.

Complete standstill/stopped for transfer to 4H to 4L. I think that a hard n fast rule to be honest mate.

Andy2640 wrote:

300bhpton wrote: So I read the manual for my new Jimny last night.

Shifting from 2H to 4H is essentially shift on the fly rated to 60mph. To do this you need the wheels point straight (because the would be spinning at different speeds left to right if you are turning) and have the front and rear wheels moving at the same speed. Ie not wheel spinning. Revs are required for the vacuum operation of the front hubs. But no need to use the clutch or shift into neutral.

Obviously shifting at low speed or stationary is less risky of accidentally shocking the system, there is less potential energy involved. And trying not to shift when wheelspinning.

Shifting to low is different because you are actually swapping ratios in the transfer box. For this you’ll want to be in neutral and/or put your foot on the clutch. Stationary is probably best, but suspect rolling at walking pace and it’ll probably still be ok.

Going down to low is hard to do whilst moving but shifting back up to high can easily be done on the move if you have a little mechanical aptitude. I haven't had any issues arise after doing it almost daily for the past 6 years.

Complete standstill/stopped for transfer to 4H to 4L. I think that a hard n fast rule to be honest mate.