[BigRay]

I've spent hours searching and am still trying to make sense of Jimny gearing options.

I have a manual 1999 Jimny JLX with some new 215/75/15 BFG KM2s and have noticed that it is struggling accelerating up hills and on the flat. Hill starts can be interesting also...
It is daily driven and sees around town and highway driving everyday and needs better performance. Not really interested in a 1.6 as the 1.3 has just been rebuilt so I'm looking at gearing. My rear diff needs replacing in the near future so was wondering if front and rear auto diffs would be lower geared and may help me. From what I have read no-one seems to be sure if auto and manual diffs are different in the Aussie market. Which brings me to transfer cases. From what I've read installing a stock transfer from another Jimny or Sierra may give me what I want, is this correct? If yes what would suit my Jimny? I'd prefer rpm at 100km/h to be less than 4500. I will consider aftermarket gearing but would like to explore my options first.

Thanks,
Ray

[sideways]

Your tyres are 5.3% bigger than standard. Stock it would be doing just over 3600rpm in top gear at 100km/h, now it would be touch over 3400.

You could install 4.3s diff gears from a VVT (2005 onwards) which would be 4.9% lower and get you just under 3600rpm. All other Australian Jimnys have 4.1 diff gears like yours.

There are no lower geared Jimny transfer cases than what you have now but if you installed a 1.3l Sierra transfer case (requires aftermarket fitting kit) that would be 6.7% lower and get you 3650. A 1l Sierra transfer would be almost 20% lower and get you almost 4100rpm.

There is a few aftermarket gearing options for the Jimny tansfer, but they're relatively expensive. There's also aftermarket 4.5 diff gears from FTS, I havent read of anyone running those yet though.

[BigRay]

Thanks! My speedo must be way out because I remember the engine doing 4000rpm at 100km/h when completely stock. You say 4.3 diff gears from a VVT, does that mean I can't use a complete VVT diff and only put the VVT gears in my original diffs? I like the sound of the 1L transfer, does it take much to make it work in my car?

Thanks,
Ray

[BigRay]

Been doing more searching, looks like I'll need a conversion kit for the 1L transfer, but I'm liking the idea of the 4.3 diff gears.

[BertZook]

BigRay wrote:

4000rpm at 100km/h when completely stock.

thats normal for your jimmy, Actually kinda remember mine being a bit over 4000 when stock.

when he said 3600rpm thats for the vvt jimnys

[GraphicX]

my 1999/2000 sits on about 4,000rpm for 100ks & i think 4,200 for 110ks (but it's doing closer to 117 at that point due to tyres). i'd love to fiddle the gearing as well so keen to see what options are out there.

[BertZook]

yup thats right, I was thinking on highway speed (110, not 100).... latter when I got 215's to travel according to GPS to 110km/h I needed to sit on 4000rpm so it wasn't bad at all, 215's no need gearing on hi in my opinion, but for low is pretty bad... now that Im in 235s is pretty bad

[BigRay]

Ah I understand now, thanks guys. Got a quote from a Suzuki wrecker in QLD (I'm from Vic) and they said $495 per diff and $150 freight. Does this sound reasonable?

Ray

[Jezza86]

i paid 1000 for a rear axle housing with a centre, but it had only done 1500K