31" for the jimny and regear

hello all!
im new here and owner of 2010 jimny, Auto Transmission
currently got 3" procomp lift and 215/75/15
i can go 31" without re gear the t-case? im using the jimny only for offroad, mostly for rock climbing.
what about the axle, do i have to get stronger shafts?

thanks!

With 31" you will need to think about regearing something. The transfer case, especially if you prefer rock crawling, would be the likely candidate. You wouldn't want to use the trailgear since those are for transfer cases with the standard transmissions and would result in a 1.17:1 high from the original 1.32:1 that you currently have. I think trialjimny still makes a kit for the push button transfer with auto. There is also protrack in Greece. If you end up doing the transfer regear, you may want to install an external cooler and temp gauge for your auto at the same time.

I’ve had 3 Jimnys now and all have had 30-31” tyres (235-75-15 and 30-10.50-15) never had problems off-roading with them did manage to do 2 cv’s over a period of about 4 years but the cars were 4 year old and 12year old tho k it was the 12yearold that did the cv’s..both sides at separate times did some small rock climbing sections off-roading at cows and in the lakes ( parkermoor being the most rocky I did) and it was always fine. I found slow and steady was the best method and less bits break

im assuming you talking about this kit that not good?
www.trail-gear.com/product/5323/jimny-electric-t-case-gears
seem like 87% on the low, do i need more than 17% on the high?
if im not installing any t-case gear. it can fail or any damage to the transmission?
i have already cooler installed.
thanks

That kit will not help much on a auto jimny as the gearing is different on manual and auto jimnys. For the kit to work at all you will need the chain from a manual jimny transfer as well..
Will be too much cost for too little down gearing.
Try rocklobster. Try to set up all your different options in the grim jeeper calculator to see what suits your car and tire size best.

That is the kit that I was commenting on. It is supposed to be very good quality (no personal experience) but is not appropriate for your Jimny.

Yakusa's points are on the money. The transfer case for the manual transmission is a 1:1 high and 2.002:1 low. The automatic is 1.32:1 high and 2.643:1 low. The point that Yakusa and I are making is that if you use the kit for a manual (17% reduction in high range) you would actually be basing the reduction on 1:1. You would end up with a 1.17:1 high range rather than your original 1.32:1 (obviously not a reduction). The grim jeeper site Yakusa mentioned is an extremely useful tool. It is here:
Gear Calculator
Using the site you can play a lot with the gearing to find what best suits you. It should be noted that the gearing of the differentials are different as well. Most market areas should have a 4.090 differential for manuals and a 4.300 for automatics.

The last point that Yakusa makes would depend on your preference. The Rocklobster is a rock solid way to go. If you would rather stay with the push-button, you can try these:
TrialJimny Reduction Gears
Or for a wider selection, try here:
Protrack Reduction Gears