[BertZook]

This was post in Monkey's build tread, I though it was betteer to make it a new tread for all of those jimny lovers who re thinking to get some kind of reduction for bigger tyres

from zukenutter - he said they were rough calculations

Mark III with Mark III gearbox + a standard 1.3 Sierra Transfer + Stock diffs = 40% reduction
Mark III with Mark III gearbox + a standard Mark II Jimny Transfer + Stock diffs = 30% reduction
Mark III with Mark II gearbox + a standard 1.3 Sierra Transfer + Stock diffs = 16% reduction
Mark III with Mark II gearbox + a standard Mark II Jimny Transfer + Stock diffs = 6% reduction
Mark II Jimny with a standard 1.3 Sierra Transfer + Stock diffs = 10% reduction
Mark II Jimny with a standard 1.3 Sierra Transfer + Mark III diffs = 16% reduction
Mark II Jimny with Mark III gearbox + a standard Mark II Jimny Transfer + Stock diffs = 30% reduction



also other options:

Trialjimny gears for Mark II Jimnys = 24% reduction
Trialjimny gears for Mark III Jimnys = 20% - 27% - 35% reduction for Manual transmission. 25% reduction for Automatic transmission

These are the 3 more common tyre sizes that Jimnys owners use and the amount of % reduction gearing needed to get it back to factory

215/75/15 = ?
235/75/15 = ?
30x9.5 = ?



Please be free to correct any mistakes and fill any gaps. Any new information post it I would update it in this first post so everyone can come back and do a quick check without going trough x amount of pages of chatting.

Also would be great if any can add info on adding 6.5 gears in sierras transfer case r 4.9 and any other option available

and thanks all for your help

[squibby]

Awesome info,

Slightly off topic maybe, but regarding tyre sizes and speedometer, the 215/75/R15 on mkIII Jimny sets the speedo 100% accurate. Any larger then this and your speedo will be reading lower then actual speed. With stock tyres your speedo reads faster then actual speed.

[Gwagensteve]

It's worth adding info for the Apio replacement planetary set too. I don't have info on it to hand, but a member of the club in the Vic added the Trialjimny replacement sprockets with the Apio planetary and ended up with 5.XX in the transfer case low range.

Steve.

[monley]

Gwagensteve wrote:

It's worth adding info for the Apio replacement planetary set too. I don't have info on it to hand, but a member of the club in the Vic added the Trialjimny replacement sprockets with the Apio planetary and ended up with 5.XX in the transfer case low range.

Steve.

Aren't they really expensive?

Also there are different diff ratios to, not sure what they are thou.

[zukenutter]

I've worked these out in the past but it's just from memory and roughly.

215/75/15 = 7%
235/75/15 = 11%
30x9.5 = Don't know, probably about 13%'ish

[zukenutter]

monkey wrote:

Gwagensteve wrote:

It's worth adding info for the Apio replacement planetary set too. I don't have info on it to hand, but a member of the club in the Vic added the Trialjimny replacement sprockets with the Apio planetary and ended up with 5.XX in the transfer case low range.

Steve.

Aren't they really expensive?

Also there are different diff ratios to, not sure what they are thou.

Diff ratios I know of are 4.09 and 4.3, I've heard stories of autos being different in either the diffs or transfer but to my knowledge nobody has ever confirmed this for the Aussie market.

EDIT: 4.3 diffs are VVT Jimny

[zukenutter]

Apio reduction on YouTube

Can't find a web listing for it For Sale though.

[09JimnySierra]

Stock Tire - 205/70R15
Tire 1 - 215/75R15
Tire 2 - 235/75R15
Tire 3 - 30x9.50R15 >Search Tires
Stock Tire - Section Width: 8.07 in 205 mm
Tire 1 - Section Width: 8.46 in 215 mm
Tire 2 - Section Width: 9.25 in 235 mm
Tire 3 - Section Width: 9.48 in 241 mm
Stock Tire - Rim Diameter: 15 in 381 mm
Tire 1 - Rim Diameter: 15 in 381 mm
Tire 2 - Rim Diameter: 15 in 381 mm
Tire 3 - Rim Diameter: 15 in 381 mm
Stock Tire - Rim Width Range: 5.5 - 7.5 in
Tire 1 - Rim Width Range: 5.5 - 7.5 in
Tire 2 - Rim Width Range: 6 - 8.5 in
Tire 3 - Rim Width Range: 6.5 - 8.5 in
Stock Tire - Overall Diameter: 26.29 in 667.76 mm
Tire 1 - Overall Diameter: 27.69 in 703.32 mm
Tire 2 - Overall Diameter: 28.87 in 733.29 mm
Tire 3 - Overall Diameter: 29.99 in 761.74 mm
Stock Tire - Sidewall Height: 5.64 in 143.25 mm
Tire 1 - Sidewall Height: 6.34 in 161.03 mm
Tire 2 - Sidewall Height: 6.93 in 176.02 mm
Tire 3 - Sidewall Height: 7.49 in 190.24 mm
Stock Tire - Radius: 13.14 in 333.75 mm
Tire 1 - Radius: 13.84 in 351.53 mm
Tire 2 - Radius: 14.43 in 366.52 mm
Tire 3 - Radius: 14.99 in 380.74 mm
Stock Tire - Circumference: 82.59 in 2097.7 mm
Tire 1 - Circumference: 86.99 in 2209.5 mm
Tire 2 - Circumference: 90.69 in 2303.5 mm
Tire 3 - Circumference: 94.21 in 2392.9 mm
Stock Tire - Revs per Mile: 791.1
Tire 1 - Revs per Mile: 751.1
Tire 2 - Revs per Mile: 720.4
Tire 3 - Revs per Mile: 693.5
Stock Tire - Actual Speed: 60 mph 100 km/h
Tire 1 - Speedometer1: 56.9 mph 94.9 km/h
Tire 2 - Speedometer1: 54.6 mph 91.0 km/h
Tire 3 - Speedometer1: 52.5 mph 87.6 km/h
Stock Tire - Speedometer Difference: -
Tire 1 - Speedometer Difference: 5.325% too slow
Tire 2 - Speedometer Difference: 9.813% too slow
Tire 3 - Speedometer Difference: 14.07% too slow
Stock Tire - Diameter Difference: -
Tire 1 - Diameter Difference: 5.06%
Tire 2 - Diameter Difference: 8.94%
Tire 3 - Diameter Difference: 12.34%

Question- is % of reduction equal to the % the speedo is out? or is the reduction ratio something different again?

I've just ordered 5x 215/75/R15 KL-71's (can't afford the reduction gears just yet)...thanks Zukenutter for the advice RE: 235's, pretty much made my mind up.

[zukenutter]

09JimnySierra wrote:

Question- is % of reduction equal to the % the speedo is out? or is the reduction ratio something different again?

I've just ordered 5x 215/75/R15 KL-71's (can't afford the reduction gears just yet)...thanks Zukenutter for the advice RE: 235's, pretty much made my mind up.

Only tyre size and diff ratio swaps will effect the speedo as it reads from the speed of rear shaft revolutions. I use GPS speed when guess-timating ratios etc, speedos are too erratic in their readings.

09JimnySierra, would you mind editing your post a bit with some spacing between sections so it's a bit easier to decipher please. Cheers.

[09JimnySierra]

Stock Tire - 205/70R15
Tire 1 - 215/75R15
Tire 2 - 235/75R15
Tire 3 - 30x9.50R15

Stock Tire - Section Width: 8.07 in 205 mm
Tire 1 - Section Width: 8.46 in 215 mm
Tire 2 - Section Width: 9.25 in 235 mm
Tire 3 - Section Width: 9.48 in 241 mm

Stock Tire - Rim Diameter: 15 in 381 mm
Tire 1 - Rim Diameter: 15 in 381 mm
Tire 2 - Rim Diameter: 15 in 381 mm
Tire 3 - Rim Diameter: 15 in 381 mm

Stock Tire - Rim Width Range: 5.5 - 7.5 in
Tire 1 - Rim Width Range: 5.5 - 7.5 in
Tire 2 - Rim Width Range: 6 - 8.5 in
Tire 3 - Rim Width Range: 6.5 - 8.5 in

Stock Tire - Overall Diameter: 26.29 in 667.76 mm
Tire 1 - Overall Diameter: 27.69 in 703.32 mm
Tire 2 - Overall Diameter: 28.87 in 733.29 mm
Tire 3 - Overall Diameter: 29.99 in 761.74 mm

Stock Tire - Sidewall Height: 5.64 in 143.25 mm
Tire 1 - Sidewall Height: 6.34 in 161.03 mm
Tire 2 - Sidewall Height: 6.93 in 176.02 mm
Tire 3 - Sidewall Height: 7.49 in 190.24 mm

Stock Tire - Radius: 13.14 in 333.75 mm
Tire 1 - Radius: 13.84 in 351.53 mm
Tire 2 - Radius: 14.43 in 366.52 mm
Tire 3 - Radius: 14.99 in 380.74 mm

Stock Tire - Circumference: 82.59 in 2097.7 mm
Tire 1 - Circumference: 86.99 in 2209.5 mm
Tire 2 - Circumference: 90.69 in 2303.5 mm
Tire 3 - Circumference: 94.21 in 2392.9 mm

Stock Tire - Revs per Mile: 791.1
Tire 1 - Revs per Mile: 751.1
Tire 2 - Revs per Mile: 720.4
Tire 3 - Revs per Mile: 693.5

Stock Tire - Actual Speed: 60 mph 100 km/h
Tire 1 - Speedometer1: 56.9 mph 94.9 km/h
Tire 2 - Speedometer1: 54.6 mph 91.0 km/h
Tire 3 - Speedometer1: 52.5 mph 87.6 km/h

Stock Tire - Speedometer Difference: -
Tire 1 - Speedometer Difference: 5.325% too slow
Tire 2 - Speedometer Difference: 9.813% too slow
Tire 3 - Speedometer Difference: 14.07% too slow

Stock Tire - Diameter Difference: -
Tire 1 - Diameter Difference: 5.06%
Tire 2 - Diameter Difference: 8.94%
Tire 3 - Diameter Difference: 12.34%

[303zuke]

From THIS thread:

"The Trial Jimny set replace the chain drive and driven gear for around 24% more reduction in high and low, the APIO set replace the planetery gears for 58% more reduction in low only.

In theory, you could fit both styes of reduction in the case for 95% more reduction (and a $3500 transfer case!)."

[303zuke]

zukenutter wrote:

Apio reduction on YouTube

Can't find a web listing for it For Sale though.

APIO don't have an English language website, but they can be purchased through the 3rd party site Rakuten. Price is 169,000 yen for the gears, or 192,000yen "With labor" and an exchange transfer case (I guess that means fitted??)

[Choppy]

http://www.bigjimny.com/images/document ... ratios.pdf

big jimny ratios

[zukenutter]

Keep in mind with any notes I've made so far that nothing is a totally straight swap and some fabricating and adjustment will be required. The info I've gathered has been through trial and error, also the percentages are a guide only, not exact.

[zukenutter]

Choppy wrote:

http://www.bigjimny.com/images/documents/transferboxratios.pdf

big jimny ratios

Use the UK models to compare to Aussie. I don't know about the higher diff ratio on the first G Series but otherwise this seems accurate. I used this table in my calculations.

[squibby]

09JimnySierra wrote:

Stock Tire - 205/70R15
Tire 1 - 215/75R15
Tire 2 - 235/75R15
Tire 3 - 30x9.50R15 >Search Tires
Stock Tire - Actual Speed: 60 mph 100 km/h
Tire 1 - Speedometer1: 56.9 mph 94.9 km/h
Tire 2 - Speedometer1: 54.6 mph 91.0 km/h
Tire 3 - Speedometer1: 52.5 mph 87.6 km/h
Stock Tire - Speedometer Difference: -
Tire 1 - Speedometer Difference: 5.325% too slow
Tire 2 - Speedometer Difference: 9.813% too slow
Tire 3 - Speedometer Difference: 14.07% too slow
Stock Tire - Diameter Difference: -
Tire 1 - Diameter Difference: 5.06%
Tire 2 - Diameter Difference: 8.94%
Tire 3 - Diameter Difference: 12.34%

Question- is % of reduction equal to the % the speedo is out? or is the reduction ratio something different again?

I've just ordered 5x 215/75/R15 KL-71's (can't afford the reduction gears just yet)...thanks Zukenutter for the advice RE: 235's, pretty much made my mind up.

Hey 09jimnysierra, have you just assumed that stock jimny with stock tyres speedo is 100% accurate? and referenced the other sizes assuming that stock tyre is 100%? not so in my experience. GPS readings showed inaccurate speedo with the stock tyres. It's set faster then actual speed, probably to cover the manufacturer for defects in the speedo, or to compensate if someone fits larger tyres. IN my experience the 215/75/R15 rectified the speedo to 100% compared to GPS speedo. Not everyones car is the same, but I reckon your guide is misleading, I reckon 215/75/R15 is the baseline amd you should reference the other tyres and stock sized compared to that. just my opinion.

[tanshi]

i believe you can also pick up 4.8 diff gears from japan, they came out in the 660 model one, but are pretty rare and last i saw about $1000 each end

[09JimnySierra]

Just for you Nutter ... if this continues i'll be lead to believe that you're just trolling the forum

Stock Tire - 215/75R15
Tire 1 - 235/75R15
Tire 2 - 30x9.50R15
Tire 3 - 31x10.50R15

Stock Tire - Section Width: 8.46 in 215 mm
Tire 1 - Section Width: 9.25 in 235 mm
Tire 2 - Section Width: 9.48 in 241 mm
Tire 3 - Section Width: 10.51 in 267 mm

Stock Tire - Rim Diameter: 15 in 381 mm
Tire 1 - Rim Diameter: 15 in 381 mm
Tire 2 - Rim Diameter: 15 in 381 mm
Tire 3 - Rim Diameter: 15 in 381 mm

Stock Tire - Rim Width Range: 5.5 - 7.5 in
Tire 1 - Rim Width Range: 6 - 8.5 in
Tire 2 - Rim Width Range: 6.5 - 8.5 in
Tire 3 - Rim Width Range: 7 - 9 in

Stock Tire - Overall Diameter: 27.69 in 703.32 mm
Tire 1 - Overall Diameter: 28.87 in 733.29 mm
Tire 2 - Overall Diameter: 29.99 in 761.74 mm
Tire 3 - Overall Diameter: 30.97 in 786.63 mm

Stock Tire - Sidewall Height: 6.34 in 161.03 mm
Tire 1 - Sidewall Height: 6.93 in 176.02 mm
Tire 2 - Sidewall Height: 7.49 in 190.24 mm
Tire 3 - Sidewall Height: 7.98 in 202.69 mm

Stock Tire - Radius: 13.84 in 351.53 mm
Tire 1 - Radius: 14.43 in 366.52 mm
Tire 2 - Radius: 14.99 in 380.74 mm
Tire 3 - Radius: 15.48 in 393.19 mm

Stock Tire - Circumference: 86.99 in 2209.5 mm
Tire 1 - Circumference: 90.69 in 2303.5 mm
Tire 2 - Circumference: 94.21 in 2392.9 mm
Tire 3 - Circumference: 97.29 in 2471.1 mm

Stock Tire - Revs per Mile: 751.1
Tire 1 - Revs per Mile: 720.4
Tire 2 - Revs per Mile: 693.5
Tire 3 - Revs per Mile: 671.6

Stock Tire - Actual Speed: 60 mph 100 km/h
Tire 1 - Speedometer1: 57.5 mph 95.9 km/h
Tire 2 - Speedometer1: 55.3 mph 92.3 km/h
Tire 3 - Speedometer1: 53.6 mph 89.4 km/h

Stock Tire - Speedometer Difference: -
Tire 1 - Speedometer Difference: 4.261% too slow
Tire 2 - Speedometer Difference: 8.305% too slow
Tire 3 - Speedometer Difference: 11.83% too slow

Stock Tire - Diameter Difference: -
Tire 1 - Diameter Difference: 4.09%
Tire 2 - Diameter Difference: 7.67%
Tire 3 - Diameter Difference: 10.6%

[09JimnySierra]

Just got this from trialjimny....for everyones info (recd. 31/05/2011)


Hello!

Our 20% and 27% gearsets are 750 EUR each and shipment to Australia
is 70 EUR.The 35% kit is 950 EUR and shipment to your country is
100 EUR.

All our gearsets fit your jimny transfer case without any
modification and are covered by a 2 year warranty that is valid
also in case of use in competitions.

Feel free to contact me anytime.

Cordiali saluti/Best regards
trialjimny.com

[zukenutter]

09JimnySierra wrote:

Just for you Nutter ... if this continues i'll be lead to believe that you're just trolling the forum

What did I say?

I only asked for some spacing and for it to be edited in your original post. Now it's there three times

[monley]

I have found some more gearing info

Here

[monley]

Quote:

If yours is a manual VVT it will have a transfer box ratio of 1:1 in high and 2.002:1 in low. The auto VVT uses a different transfer box that is 1.32:1 in high and 2.643:1 in low, so could be an easy swap and still giving you a good reduction.
The manual car has 4.3:1 diffs and I think they are the same for the auto.

I think using a AUTO t-case from a VVT jimny sounds like a easy path for me now just trying to figure out what sort of reduction it;s going to offer...

[zuk85]

prolly a stupid question. But how do I tell if im mark II or III

october 2006 plated, vvt jimny.

[BertZook]

Mark III


Mark I = first jimnys, early models, non-airbags
Mark II = airbags ones
Mark III = vvt's and push button thingys

[BertZook]

squibby wrote:

09JimnySierra wrote:

Stock Tire - 205/70R15
Tire 1 - 215/75R15
Tire 2 - 235/75R15
Tire 3 - 30x9.50R15 >Search Tires
Stock Tire - Actual Speed: 60 mph 100 km/h
Tire 1 - Speedometer1: 56.9 mph 94.9 km/h
Tire 2 - Speedometer1: 54.6 mph 91.0 km/h
Tire 3 - Speedometer1: 52.5 mph 87.6 km/h
Stock Tire - Speedometer Difference: -
Tire 1 - Speedometer Difference: 5.325% too slow
Tire 2 - Speedometer Difference: 9.813% too slow
Tire 3 - Speedometer Difference: 14.07% too slow
Stock Tire - Diameter Difference: -
Tire 1 - Diameter Difference: 5.06%
Tire 2 - Diameter Difference: 8.94%
Tire 3 - Diameter Difference: 12.34%

Question- is % of reduction equal to the % the speedo is out? or is the reduction ratio something different again?

I've just ordered 5x 215/75/R15 KL-71's (can't afford the reduction gears just yet)...thanks Zukenutter for the advice RE: 235's, pretty much made my mind up.

Hey 09jimnysierra, have you just assumed that stock jimny with stock tyres speedo is 100% accurate? and referenced the other sizes assuming that stock tyre is 100%? not so in my experience. GPS readings showed inaccurate speedo with the stock tyres. It's set faster then actual speed, probably to cover the manufacturer for defects in the speedo, or to compensate if someone fits larger tyres. IN my experience the 215/75/R15 rectified the speedo to 100% compared to GPS speedo. Not everyones car is the same, but I reckon your guide is misleading, I reckon 215/75/R15 is the baseline amd you should reference the other tyres and stock sized compared to that. just my opinion.

I knew this was bit weird, and I had a feeling it probs was only with vvt's so I finally check it in mine

Mine is a MarkII jimny (2002 model)

I have 215/75/r15 and finally yesterday I have a GPS with me and Im 5 km/h out in my speedo...... so If Im doing 100Km/h, my speedo reads 95Km/h


so keep that in mine of that..... 205/70/r15 keep being stock tyres, not only as the 215's trow ur speedo out but also ur performance a bit too

so maybe this is a issue of Mark I and II jimnys.... and vvts is different?

[monley]

I have now got 20% trail jimny gears in...4100rpm@100KPH with slightly under size 235's. Pulls great!!!

[zukenutter]

monkey wrote:

I have now got 20% trail jimny gears in...4100rpm@100KPH with slightly under size 235's. Pulls great!!!

Now you understand what all the fuss about gears is for. So much nicer to drive.

[zuk85]

I need to find a mark II transfercase for my mark III jimny lol :D:D 30% ohh yea lol

anyone know if its a simple straight in straight out swap?? or the old different flanges and shafts and shit like the sierra case?

[zukenutter]

zuk85 wrote:

I need to find a mark II transfercase for my mark III jimny lol :D:D 30% ohh yea lol

anyone know if its a simple straight in straight out swap?? or the old different flanges and shafts and shit like the sierra case?

From memory everything bolts up perfectly but you'll need to have a custom made jack shaft. Also you'll need to find a Mark II transfer lever boot for the cab.

[squibby]

So if I put a MkII transfer into my MkIII, does the reduction only come into play when in low range, or is it always effective?