[Xtreme]

I have been having a bot of a look through the info on here and see some conflicting information about whether or not the Jimny auto is weak or not? Mine is a 99 manual but I am thinking of putting an auto in it as part of my build, but I don't want to put one in there if it's weaker then the manual.

1. Is there any agreement on here - is the Jimny auto weak?

2. I have 31's, have a WT TC that I want to put in but will be running 4.16 or 4.9 gears? (Can't remember which was suggested to me I need to look through my messages) and the Jimny auto would also further increase the low range reduction is that correct?

3. What kind of RPM could I expect to sit on for 90/km/hr or 100km/hr with this set up?
3a. On this note am I correct that 5.16 gears would leave me sitting on 4000RPM at 80kim/hr or close to? However 5.16 gearing would give me better low range crawling ability right?

4. Is there another auto that is considered stronger then the Jimny (if it IS considered weak) that is a fairly easy swap? (no tunnel modification) eg Vitara? what would the gearing effect of this be on the above mentioned set up?

5. If there is not an easy option is there modifications that can be performed on the Jimny auto to help it out?

Thats about all the questions I have for now cheers guys.

[Joshyboy26]

I think temp is their biggest killer. Put a cooler and fan setup and gauge on it, and make sure it doesn't get hot itll be fine. Don't get too worried about it.

[Gwagensteve]

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1. Is there any agreement on here - is the Jimny auto weak?

The jimny auto is at the limit of its torque handling capacity behind a G13BB. (110Nm) This is unlike the vitara autos, which can handle far more torque than their sent by the vitara engines.

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2. I have 31's, have a WT TC that I want to put in but will be running 4.16 or 4.9 gears? (Can't remember which was suggested to me I need to look through my messages) and the Jimny auto would also further increase the low range reduction is that correct?

Sort of. 1st gear in the Jimny auto is 2.95 or thereabouts - its not lower than your manual. However, the torque converter can slip and when it does it acts as a gear reduction - the ratio is around 2:1, so when engine revs are below torque converter stall speed (circa 2000rpm) and load is high, you can get an equivalent 6:1 out of first gear. However, once revs rise above stall speed, you're back at whatever numerical gear ratio the gearbox offers. This is great for crawling, but slipping the converter generates LOADS of heat, and heat kills automatics.

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3. What kind of RPM could I expect to sit on for 90/km/hr or 100km/hr with this set up?

Cant help there. Search the ratios of the Jimny auto in 4th and compare that to your manual. It's likely cruise revs will drop a bit.

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3a. On this note am I correct that 5.16 gears would leave me sitting on 4000RPM at 80kim/hr or close to? However 5.16 gearing would give me better low range crawling ability right?

As above. You'll have to crunch those numbers for yourself. It's not hard to build a gearing calculator in excel - it's 10 minutes well spent.

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4. Is there another auto that is considered stronger then the Jimny (if it IS considered weak) that is a fairly easy swap? (no tunnel modification) eg Vitara? what would the gearing effect of this be on the above mentioned set up?

No auto will fit without tunnel mods. Every other auto is stronger. Trimatic from a carby vitara would be the easiest fit with a lucky 13 adapter but you might have issues with road gearing (or maybe not - don't jimny's have a direct 5th gear?) the AW-4 is probably the ultimate auto, but it's bulky and requires electronics to make it shift. It has very nice gearing though and is well suited to off road work. Any auto is going to require jackshaft and mount modifications, work to adapt a shifter, tunnel mods, some wiring, potentially a kick down (TV) cable install, cooler and gauge. It's not a small job. Tunnel mods are neither here or there.

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5. If there is not an easy option is there modifications that can be performed on the Jimny auto to help it out?

The first thing is to make sure you're not using the auto to correct for inadequate gearing. If the auto won't lock the converter on cruise and you're slipping the converter hard off the line it's going to die. Gearing needs to be spot on. Then, a really big cooler, or two, and a gauge. There's nothing else. These autos don't have any aftermarket support so there isn't a shift kit or upgraded clutches or anything for them.

[Xtreme]

How many of you guys would prefer an auto over a manual in the Jimny if you could get your hands on one (depending on what you want to do off road of course) ? I just figured it might be a bit easier on the slower rock work then the manual and if I can control the heat then it might be a good option for me although I do like driving manual

[Gwagensteve]

There's no good reason to drive a manual in technical terrain. Autos are on a different planet for control.

[joeblow]

Again, someone who has not done this mod offers his expertise.

There are no tunnel modes needed for the AW4 in a Jimny. Only a new mount system.

Buy a Jimny auto shift and plastic housing and your life just got a lot easier too.

[pezz]

Sookie wheels a stock auto jimny with 31's on it, his auto is still going strong.... so far

if I could score a cheap gpowered auto jimny id run it in mine

[Dan85]

Hey Joe how much a Jimny aw4 conversion kit

[Gwagensteve]

I'm sure the op thanks you for clarifying that and assisting him with the gearing implications of the swap.

Steve.