lower gearing

hi guys i want to fit lower gearing to my jimny it got 31s on it. its ok but needs a bit of help on the road so i want to no whots avaialble any kits to fit in the box my mate can take the box apart or is thear a cog to go in like the ones you can get for sjs any info would be great thanks bazz

I only know of two "kits" (if anyone else knows of any please jump in!)

The first is the TrialJimny gearset www.geocities.com/trialjimny/jimny.html which uses your existing transfer box and drops new gears in.

The second (which is done by a lot of suppliers - RhinoRay, Offroad-Armory, D&G Tuning) replaces the Jimny Transfer box with an SJ box.

Neither are cheap. The TrialJimny set involves properly machined gears so is expensive. The SJ box replacement versions require you to already have a converted SJ box (ie. RockLobster) to hand and then charge you for mounts and propshaft adaptions.

It would be very easy to spend £1000 on the SJ conversion if you bought all the bits through commercial sources, although if you built the parts yourself it could be a lot cheaper.

I have TrialJimny gears fitted and whilst they are ok they are not brilliant, the SJ conversion provides you with much lower ratios.

Martin

thanks martin, i spoke to rhino ray today, he said about £1600 to put the sj box in. have you any idea how much your trial jimny gear set cost? im having to rev it hard on long hills,like 3rd gear all the way up about 4000rpm 40mph, (change to fourth and it dies) do you think i will eventually end up killing the engine even tho i regurally service it, even tho i dont let it rev over 4500rpm?? cheers m8 - bazz

I think they cost around £300 - drop them a email - apparently they are quite friendly to deal with.

I did forget one other supplier I know of - APIO www.rakuten.co.jp/apio/ but its all in Japanese. They are supposed to do a really low ratio set of gear and the technical person who answers emails can email in English. The parts from this company are the bees knees in Jimny parts.

Martin

Also have a word with offroad-armory as they do good stuff and compete with RhinoRay.

Martin

thanks martin, ill give off-road armoury a ring and find out, thanks for your help.
bazz

Can you let me know how you get on with gearing mate as i would also like to lower my gearing.
I am running 30s off road and find it a bit high! Martin How do you find your gearing off road? Is it gearing 2nd more or less like standerd 1st Gear? Thanks Dave

Unlike an SJ conversion which only affect low range, the TrialJimny modification is a 24% reduction in both High and Low range meaning. Its hard to judge it in terms of "2nd has moved to 1st", basically it lowers it a bit overcoming slightly the problem of large tyres.

Basically in Low Gear 1st I still need brakes as it is not low enough for full "feet off" descents. On the motorway in High 5th it runs out of poke at an indicated 60 MPH, but remember this speedo setting is also affected by the tyres and is lower than reality.

My schoolboy maths says my tyres are 7% bigger in diameter, making them 7% bigger in circumference. Therefore my speedo reads 7% low (so my 60 MPH is more like 65 MPH).

The 24% overall lowering recovers all of this 6% raising so it recovers all the changes in tyre diameter plus a bit.

I expect someone will work out there is a flaw in the maths but it feels close to reality

Martin

[NOTE: I worked out for myself there was a flaw in the maths! and think I sorted it out]

235/75/R15 tyres approx. 29 inches diameter = 7% increase
265/75/R15 tyres approx. 31 inches diameter = 13% increase

I find that i only use 1st gear sometimes its good gearing but when i try doing slow manovers it seems a wee bit to high. Would not like to be trying to choose between 1st and 2nd all the time pitty i dident live closer i could have seen what urs was like.

Well if your ever "down south" let me know....

....and one day we should come to Drumclog.

Have you heard of anyone using any gear kits from the suplier from japan Martin? Was wondering how low the gearing was? And what kind of price? Was going to fit trial jimny gearing but worried i might need to use 2nd gear more and gearing still a bit high for second and bit low for first gear.. Hope you understand what i mean i am talking in ridels

A couple of the Asian Jimny owners on www.jimny.se use the Apio Star58 gearset.

There is an excellent thread on the jimny forum that explains the different gearing options and their relative pricings.

Here is the original article www.jimny.se/phpbb/viewtopic.php?t=1151 written by a guy called Squik - the highlights are below:

In essence the TrialJimny gearset reduces ALL the ratio's (high and low) by about 24%, therefore it compensates for tyre size changes up to around 30/31 inches - looks to be around £700

The Star58 gearset reduces low ratio ONLY by 58% so is the more of a "RockCrawler" conversion - yours for around £900

There is a D&GTuning conversion which puts an SJ transfer box onto the car - around £850 plus you have to find an SJ tranfer box

If you can put up with the eyewatering costs then you can fit the TrialJimny gearset with the Apio Star58 gearset to create a lower overall gearing for large tyres along with a lower ratio low gear.

I have the TrialJimny Gears fitted and whilst they do offset the larger tyres they cannot be called RockCrawler gears.

One day (in my dreams) I might try for the Apio Star58 set. Perhaps once off-raoding Jimnys becomes more main stream someone will manufacture a similar gearset in the EU.

Martin