Oils (and other fluids) for the Gen4 Jimny JB/JC74
This is an area of endless debate so I thought I’d capture everything about the key fluids for the car. This isn’t the ‘how to change these fluids’ page, this is the ‘what fluids’ page. If you’re looking for how to service the car, then my Jimny servicing page is for you.
The range of Suzuki official lubricants and fluids is here, provided by Ecstar Europe.
Sections
- Quick reference table
- Engine oil
- Manual transmission oil
- Automatic transmission fluid
- Transfer case oil
- Differential oil
- Coolant
- Brake fluid
- Front CV grease
- Propeller shafts
- Power steering
Quick reference table
| Fill area | Viscosity / type | Capacity | Oher |
|---|---|---|---|
| Engine oil | 0W20 (5W30) synthetic | 4L including filter | Synthetic; GF-6A; SN API grade |
| M/T oil | 75W-80 GL-4 | 1.2L | Synthetic recommended; note GL-4 |
| A/T fluid | Suzuki 3317 | ~3-4L (5.7L total fill on overhaul) | Suzuki ATF3317, with these fluids meeting it or recommended as compatible: * Ecstar ATF 3317 * Castrol TRANSMAX Dexron®-VI Mercon® LV Multivehicle * Penrite ATF FS |
| Transfer case | 75W-80 GL-4 | 1.2L | Also GL-4 fluid as contains synchroniser on high<->low shift |
| Differential | 75W-85 GL-5 | Front: 1.6L Rear: 1.3L | Note GL-5, fully synthetic highly recommended |
| Coolant | Long life glycol | 5L | Cars until mid 2022 received Suzuki blue ultra long life coolant; now receive green long life coolant. |
| Brake fluid | DOT3 | ~800 mL if completely dry | Note shared reservoir for brakes and clutch on manual cars; only DOT3 is required although DOT4 can be used |
| Front CV grease | Suzuki Super Grease C – 99000-25030 (tan, lithium based) | ~100 g per CV | Hard to get specs on the grease; a translation of the German cross-reference guide suggests it’s an NLGI 2 lithium grease, waterproof and -25 to 180º C thermal resistance. I generally recommend a high moly but lithium based grease for CVs or maybe Castrol LMM. Just clean the swivel hub and axle out fully. Also use this grease for the kingpin bearings if they’re dry. |
| Kingpin bearings | Not specified | Enough | Use the same as the front CV grease when you rebuild swivel hubs |
| Propeller shafts | Suzuki Super Grease C – 99000-25030 (tan, lithium based) | Till it comes out of uni joints; a small smear on the sliding joint on front propshaft | Plenty of sites seem to say this is also Super Grease A, but the part number matches what the workshop instructions call Super Grease C. |
| Power steering | It doesn’t need any: all electric | Electrons | Just make sure the car can supply electrons |
Engine oil
I currently run: Penrite Enviro+ 0W-20 and it needs ~4L to fill sump and the oil filter
This is the engine oil chart for markets other than Europe (where 0W16 is the recommended oil).
As you can see, there is a range of recommended viscosities depending on ambient temperature; however, the standard fill oil is a 0W20 oil. While arguments abound about low viscosity oil and how they’re only valid for ensuring better emissions numbers, cars in general have been lasting ever longer despite lower engine oil viscosities and longer oil change intervals. In Australia, note that many dealerships stick with a 5W30 oil for the Jimnys as a) it’s what they have to hand for most of their other cars and b) it’s marginally cheaper.
The problem with going too thick with an oil is slower lubrication on startup and more potential for the oil to bypass the filter where it exceeds either filter pressure drop or bulk oil pressure due to its thickness. Arguments against thin oil generally are around engine longevity, though the bulk of engine wear is on startup around the piston rings/bores and potentially thicker oils don’t do anything to help there. The K15B engine runs relatively tight bearing tolerances and piston clearances, so I err on the side of the thinnest oil I’m comfortable with: I run the factory recommended 0W20 oil.
Delving deeper: why would it be so thin?
When I refer to tighter tolerances, here’s a comparison of tolerances between the M13A engines used in a gen3 Jimny and the K15B in a gen4 Jimny.
| M13A SN413 | K15B A6G415 | Which is tighter? | |
|---|---|---|---|
| Main bearing clearance | ~45 mm crank journal diameter, clearances are 0.025 mm – 0.045 mm (0.06 – 0.1%), limit 0.065 mm (0.14%) | ~45 mm crank journal diameter, clearances are Bearing 1: 0.014-0.032 mm (~0.031 – 0.071%), limit 0.055 mm (~0.1%) Other bearings: 0.016 – 0.034 mm (~0.035 – 0.076%), limit 0.050 mm (~0.1%) | K15B |
| Big end clearance | ~42 mm crank pin diameter, clearances are 0.029 – 0.047 mm (0.07 – 0.1%), limit 0.065 mm (0.15%) | ~38 mm crank pin diameter, clearances are 0.031 – 0.049 mm (0.08 – 0.13%), limit 0.065 (0.17%) | M13A |
| Little end clearance | ~20 mm wrist pin diameter, clearances are 0.003 – 0.014 mm (0.02 – 0.1%) | ~18 mm wrist pin diameter, clearances are 0.003 – 0.017 mm (0.02 – 0.1%) | M13A |
| Cam journal clearance | #1 bearings (~26.95 mm): 0.045 – 0.087 mm (0.2 – 0.3%), limit 0.12 mm (0.5%) Others: (~23.00 mm): 0.045 – 0.087 mm (0.2 – 0.4%), limit 0.12 mm (0.5%) | Intake #1 (~29.45 mm): 0.031 – 0.081 mm (0.1 – 0.3%), limit 0.10 mm (0.3%) Exhaust #1 (~26.95 mm): 0.045 – 0.087 mm (0.2 – 0.3%), limit 0.10 mm (0.4%) Others (~22.95 mm): 0.045 – 0.087 mm (0.2 – 0.4%), limit 0.10 mm (0.4%) | K15B |
| Piston to bore clearance | Bore 78 mm New: 0.032 – 0.061 mm (0.04% to 0.08%) Limit: 0.161 mm (0.2%) | Bore 74 mm New: -0.016 to 0.030 mm (0 to 0.04%) Used: 0.010 to 0.036 mm (0.01% to 0.05%) Limit: 0.072 mm (0.1%) | K15B |
| Piston ring end gaps | Top: 0.20 – 0.35 mm (0.3 – 0.4%), limit 0.7 mm (0.9%) 2nd: 0.30 – 0.45 mm (0.4 – 0.6%), limit 1.0 mm (1.3%) Oil: 0.20 – 0.7 mm (0.3 – 0.9%), limit 1.5 mm (1.9%) | Top: 0.15 – 0.25 mm (0.2 – 0.3%), limit 0.7 mm (0.9%) 2nd: 0.25 – 0.38 mm (0.3 – 0.5%), limit 1.0 mm (1.4%) Oil: 0.10 – 0.40 mm (0.1 – 0.5%), limit 1.2 mm (1.6%) | K15B |
In short: most tolerances, even accounting for different diameters of the starting material, are tighter compared to a gen3 Jimny (which was specced for 5W30 oil, and up to 10W40 in hot climates). The tolerances are that much tighter, and that necessitates a thinner oil. In particular, the main bearings and also the piston to bore clearances are reasonably tighter than the M13A engine. This isn’t unexpected, but it does mean thinner oil is the sensible choice due to these tighter tolerances. Yes, in some ways the K15B is not a sophisticated modern engine, but it has the tolerances to be one.
Ignoring that, if you are in favour of a thicker oil I suggest you go back and read some of the linked content I’ve provided. Engines (and cars) are lasting longer than ever before, despite thinner oils changed less often. There’s good science that the oil viscosity isn’t going to do too much for the predominant area of engine wear which is around the piston, rings and bores. Bearing numbers in the lab are one thing, and wear scars are super dramatic to look at, but that isn’t even the major part to worry about with car engines (save for design flaws like BMW V10 rod bearings).
Manual transmission oil
I currently run: Penrite Pro-gear 70W-75 full synthetic and it needs 1.2L to fill
It’s a relatively simple and oldschool 5 speed manual transmission, so not super critical on fluid choice here. Interestingly Suzuki’s workshop manual recommends Suzuki Gear Oil 75W but then they give a viscosity charge for 75W-80. Seems to shift nice and fine with the 70W-75 in it and no changes in noise or appreciable metal in the oil.
I think people under-change manual transmission fluids, they cop a beating in something where you’re perpetually rowing the gears so for me this is a once-every-2-years at a minimum. Reality is it’s done when I do the transfer case, which I generally do after a lot of heavy 4wding, so more frequently than every 2 years.
Automatic transmission fluid
(I don’t have an auto, but if I did I’d probably stick to factory fluid bought from the dealership). It needs ~4L though numbers vary down to 3L for a fluid change (spec is 5.7L for total dry after a rebuild).
This one’s a funny one. The spec is Suzuki ATF3317 which basically noone says they do. It seems to be equivalent to JWS3317, which then people say is equivalent to JWS3309 which a lot more people use.
It’s a relatively oldschool style 4 speed torque converter automatic, however, electronic shifting and usually tight solenoids mean they can still be quite sensitive to fluids; my general advice is to stick to a factory fluid simply because it’s a known quantity. The transmission is ‘self-learning’, not for shift patterns but for shift speeds versus line pressures internally. Quoting the repair instructions:
Optimum line pressure complying with engine torque is produced by the pressure control solenoid valve in dependence upon control signal from TCM. This makes it possible to control the line pressure with high accuracy in accordance with the engine power and running conditions to achieve smooth shifting characteristics and high efficiency in power transmission.
Suzuki JB74 workshop manual
…
A line pressure learning control is conducted to provide optimum shifting time at every upshifting with engine throttle opened. If long upshifting time is detected, the subsequent line pressure applied during upshifting is intensified. On the contrary, if short upshifting time is detected, the subsequent line pressure applied during upshifting is weakened.
Different fluids will have different temperature-viscosity and hence pressure characteristics, which is why shifting can be so sensitive to fluid types (and also fluid contamination).
Both Castrol and Penrite suggest they have fluids compatible. Castrol TRANSMAX Dexron®-VI Mercon® LV Multivehicle explicitly is compatible, Penrite ATF FS is not explicit in its compatibility but Penrite now list it as compatible with the Jimny. The transmission is not hugely different to the gen 3 Jimny automatic, but clearly there are reasons for updating the fluid.
A key challenge with the automatic is just how hard it is to extend the transmission breather. This makes the fluid prone to contamination in certain 4wding conditions (especially deep mud and/or deep water crossings). I would be changing the fluid at the first sign of shifting unhappiness after 4wding. If this is ignored the car can end up stuck in a gear (usually first or second) or end up either not locking up the converter on the highway or the lockup clutch stuck engaged. All of these are clearly a bad time.
Transfer case oil
I currently run: Penrite Pro-gear 70W-75 full synthetic and it needs 1L to 1.2L to fill.
This is a pretty uncontroversial area. Suzuki officially specify the same 75W gear oil as the manual transmission, but then are more particular about it being synthetic and show it was a 75W-80 gear oil in the viscosity chart like the manual, too.
I have tried using some anti wear-noise additives to see if that slows down or eases the classic Jimny fart on takeoff from the transfer case chain harmonics, but it doesn’t really seem to do anything. I’m also not seeing any visible wear particles, even after nearly 6 years, from the transfer case chain being noisy, either.
If you use the same fluid as the manual transmission, a 2.5L bottle does both the transmission and transfer case. Makes it an easy change after some heavy 4wding where the transfer case definitely will be seeing some added oil shearing.
Differential oil
I currently run: Penrite Pro-Gear 75W-85 GL-5 full synthetic; 1.6L front and 1.3L rear fill capacities.
Biggest thing here is ensuring you get a GL-5 spec gear oil for the appropriate extreme pressure wear additives. One of the challenges is that many places do not carry the GL-5 spec synthetic oil in the appropriate viscosity, as the Jimny runs a lower viscosity differential oil than many people might think.
If you have a different differential setup, such as an LSD or a locked diff, then your manufacturer should be consulted. ARB suggest a particular oil for air lockers like I have, but then they also are ok using the factory Suzuki suggestions for the Suzuki lockers. Other brands or types, such as e-lockers, may be different.
Coolant
I currently run: whatever factory fill is in mine (blue Suzuki ultra long life coolant)
Coolant’s another interesting one. The original few years of Jimnys coming to Australia received the blue ultra long life coolant. This is scheduled to be replaced after 8 years or 150,000 km, after which it’s 4 years/75,000 km.
At some point, more and more appeared to come with green Suzuki coolant, which is to be replaced every 3 years/45,000 km. Interesting this isn’t listed as part of the official capped price service intervals, so it’s hard to know if it’s just a change in colour to the ultra long life coolant, or, it’s actually the regular long life green coolant.
Coolants can be exceptionally incompatible and so it is generally best to stick with what’s there if you’re doing a coolant change. If you need a small top-up then distilled water is the best call rather than risking incompatible coolants.
The Suzuki blue and green coolants are both ethylene glycol based coolants; however, they do have different additive packages. This additive packages can be the source of incompatibilities between coolant types and why you shouldn’t necessarily mix them.
If you are sticking with the Suzuki coolant then it is available through both Suzuki car and motorcycle dealers. If wanting a similar style coolant but prepared to do a full flush then the Penrite blue ultra long life fluid has similar specs to the factory blue coolant. In applications using the green coolant I have received good service and no corrosion of coolant system components using the Nulon green long life concentrate for another option.
Brake fluid
I currently run: whatever is a different colour DOT3 or DOT4 fluid to what I used last time, so I can more easily see when I’m doing a brake fluid flush
This is an often neglected part in any service regime, but especially so on a 4wd. The Jimny is not particularly picky about this fluid: in fact, a DOT3 fluid is all that is required. The Jimny doesn’t really have the braking power (or outright velocity) to warrant the higher boiling point fluids. I generally use a DOT4 fluid since that’s what my other cars use.
Whenever I change the brake fluid (usually every 2 years, but it’s also as often as whenever wheel bearings need doing) I try to use different brands. This is because different brands are (usually) different colours, e.g. swapping between Castrol (a light yellow) and Bendix (a reasonably dark blue) helps me see when the old fluid is out of that brake line and the new fluid is through.
Contrary to popular opinion, you don’t need to do anything special with the ABS pump to flush through fluid or even bleed the brakes (assuming you didn’t get air into the ABS pump, that is). I suck out the reservoir almost entirely, refill with my new fluid right to the top, and then pull fluid through. A full flush like that takes ~500 mL of brake fluid.
Bonus info: brake caliper pin grease
This is even more often forgotten on 4wds! Especially those that go in the mud will have a hard time and you’ll find the sliding caliper pins cop abuse and the caliper will stop sliding. This means you wear out one brake pad per wheel only (rather than both), and you’ll also have a more wooden brake pedal but less stopping power.
Suzuki’s official requirement is just a ‘rubber grease’ but almost all brake service places will recommend a specific high temperature grease for caliper slides. I use a Bendix caliper grease for this, which is available in individual packets at auto parts stores in Australia.
Front CV grease
Look, it’s barely a fluid on human timescales and at room temperature but I don’t see this commonly discussed anywhere and wanted to make sure it’s documented somewhere. Also, I haven’t changed this but I have helped people out who have.
In theory the grease is a lithium based grease, tan in colour and NLGI 2 grade (Suzuki Super Grease “C”). So long as you clean out whatever’s there then you can repack it with anything suitable for CVs; something with a reasonable amount of moly is a good choice for CV longevity. Over the years I have had good experience with Castrol LMM in particular.
This is a good time for a diversion about greases and their bases. Greases are essentially an oil and a thickener, usually a soap. The big thing to understand is that you shouldn’t mix greases of different bases e.g. a lithium versus a calcium versus a sodium grease. Sometimes the base also matters for the purpose of corrosion resistance depending on the metal or other material that the grease is lubricating or protecting.
Assuming there is no corrosion related difference between grease bases, it is possible to wash out an old grease of a different base using solvents and then put in a new grease with whatever base you want. This is often how one deals with unknown OEM greases
Kingpin bearings
Pretty well related to the front CVs, the kingpin bearings are what allow the swivel hub to swivel. There are no specific instructions for adding grease to them or even what grease one would use, but I would use whatever you are using for the front CVs to add some grease there. Worn kingpin bearings from insufficient/washed out grease is a pretty common cause of steering wobbles in all manner of solid axle 4wds, and the Jimny is no exception.
Propeller shafts
The propeller or propshafts (sometimes called driveshafts) are the shafts that run from the output flanges of the transfer case to the differentials, and from the output of the transmission to the input of the transfer case. Workshop instructions indicate three areas to grease on these relating to the universal joints (uni joints), although not all shafts have been manufactured with grease nipples on the uni joints.
Grease is “Suzuki Grease C” (part number 99000-25030), same as used for front CV joints.
Power steering
I’ve added this only because a few people have asked me about checking or refilling the JB74’s power steering reservoir. The short answer is it doesn’t have one as it uses entirely electric power steering assistance. This is done in the steering column itself.
There would be lubrication included inside the steering box itself but there are no repair instructions or servicing information provided by Suzuki. Presumably the manufacturer of the steering boxes handles that and they are not directly aimed at user servicability (not uncommon in steering boxes). Usually it’s a gear oil a bit like you’d use in the diffs, but without specific instructions it’s all just guesswork anyway.