Suspension advice.

My issue has been mashing the ring that surrounds the drain plug. Does anyone have a solution for that, without fitting one of those protection plates that loses me 20-30mm of clearance?

The ring you are talking about is a substantial piece of steel and is designed to protect the drain plug. As long as you are not damaging the plug itself to the point that it cannot be removed, then the ring is doing it's job. I would be interested in knowing the sort of terrain you are driving over to "mash" the ring to an extent that worries you. It is possible to reinforce the ring with extra steel but to do it properly needs, in my opinion, the removal of the casing from the vehicle.

Roger

wrote:

Many of the bolt-on options available for the Jimny are substantial fabricated items that reduce clearance by much more than a few mm, and have a much bigger frontal area too compared to a smooth rounded diff housing.

I hear what you are saying and do agree, although it is a case of 6 of one and half dozen of the other....

On my Land Rover I don't run diff guards and never have. Never felt the need for them and 90% of my off roading is not on rocks. Having said that, when laning this year in Wales, by brother reversed into a boulder and put a good dink into his rear diff. Very lucky it didn't jam up the crown wheel.

The Jimny has less clearance under the diffs, which means any protection reduces this further. But being lower makes them more vulnerable too. As in, on the same terrain, I feel I'd stand more chance bashing the Jimny's diffs than I would the Land Rover's. Therefore to some extent it is a trafe off I'm happy to make and run the guards on the Jimny.

Likewise the Jimny also gets hung up on the transfer case and the radius arms. I have the transfer case skid plate and will be getting the radius arm ones, even though technically both reduce clearance. But both will also protect the vehicle. On the Land Rover I only run a steering guard and don't think I have ever hit the under side of the vehicle.

wrote:

My issue has been mashing the ring that surrounds the drain plug. Does anyone have a solution for that, without fitting one of those protection plates that loses me 20-30mm of clearance?
here is the solution to this problem too:
weld a steel ring with the following dimensions: 36.40x41.40x7 mm H and you can go rock crawling with your Jimny every day....

Giacomo
 

As I was saying the other day, thank you so much for all the advice

Reading your answers I see that there is value in a 40mm lift, since it is true that angles will significantly improve, particularly when going through slopes etc., so I think I will go for that. If I kept my original idea of a bespoke suspension, this would mean:

- H&R springs, 40mm lift.
- Raised height Bilstein B6 shock absorbers
- ABS relocation kit
- Extended braided brake line kit
- Front lower crossmember brace
- Headlight leveling bracket
- Caster increase bushes

Initially I was also considering to install the Hardrace Front sway bar. It would improve handling on road but, as you mentioned, decrease flexing, so I think I will leave it outside by now. Alternatively, I could go for a full suspension kit, as some of you suggested. In this regard, I was looking at the one made by Though Dog, that has good reputation in Australia, but I don´t know much about any of the brands for 4WD vehicles.

Regarding cars, I was an amateur rally driver in Spain for several years, and I still have my car in there. Sadly, I don´t get to drive it much nowadays. I feel comfortable designing a suspension for a sports car, particularly if it is for the VAG group, BUT the Jimny is my first 4WD and I understand that many things are very different and do not apply to it. For example, in a regular car (particularly with the power of the Jimny) Bilstein + H&R tends to be a great combination, and you definitely won´t go wrong choosing polyurethane SuperPro bushes. However, in the Jimny I was advised against polyurethane, is this because it would make the ride significantly harsher? I still feel pretty confident regarding the shock absorbers and springs combo, though, and as far as I know it was developed specifically for the Jimny by Bilstein.

About car usage, well, I like traveling and photography a lot and I tend to go to very lonely places on my own, particularly here in Australia. I am not the type of person that feels the urge to take the car to a muddy/rocky track just because he can, though, cars are expensive. That said, I don´t want to be stopped just because the road is a disaster or because the track becomes difficult all the sudden. For example, I plan to take this guy to the desert sooner rather than later and I would like to be reasonably prepared for this. The underbody is protected because I think that in here the worst thing that can happen is to seriously damage a critical part while being all alone in the middle of nowhere. You will manage to eventually call somebody, but it may be a nightmare.

Finally, about the caster correction, I believe that if you are picky it should be in box axles. Yes, I totally agree that you don´t have steering in the rear, but that does not mean that the geometry of the spring is not going to change. There will be more tension there and in a normal car you should be able to notice the difference (and, definitely, the machine too). This may not be so relevant in the Jimnny though!

The Jimny is not a rally car. It is deliberately designed to have a large range of movement and compliance in the suspension, to maintain wheel contact, and therefore traction and stability, over very undulating ground. Part of this compliance comes from the use of soft rubber bushings in the axle ends of the radius arms which allow a large amount of deflection. The deflection is critical to the movement of the axle, as in articulation the axle effectively twists relative to the radius arms. Stiffer bushes here will only serve to restrict the normal movement of the suspension. In other areas, such as the chassis ends of the radius arms and the panhard rods they can be used without hindering the suspension's movement, although they may transmit more harshness to the cabin.
Regarding reliability in the desert, I understand your concerns but you need to weigh up the chances of being stranded due to an impact damaging a component vs the chances of getting stuck. The diff guards reduce your chance of damaging the diff (a very rare occurrence) but increase your chances of getting stuck (a relatively common occurrence). If need be you could drive a long way with no oil in the differential, but if you're stuck then you're not going anywhere.
All of the vehicles I drove in the bush were essentially standard with the exception of a sturdy roo bar and tall, narrow tyres. Tall to increase ground clearance and the tyre footprint, and narrow to reduce the chance of punctures.

wrote:

Regarding cars, I was an amateur rally driver in Spain for several years, and I still have my car in there. Sadly, I don´t get to drive it much nowadays. I feel comfortable designing a suspension for a sports car, particularly if it is for the VAG group, BUT the Jimny is my first 4WD and I understand that many things are very different and do not apply to it. For example, in a regular car (particularly with the power of the Jimny) Bilstein + H&R tends to be a great combination, and you definitely won´t go wrong choosing polyurethane SuperPro bushes. However, in the Jimny I was advised against polyurethane, is this because it would make the ride significantly harsher? I still feel pretty confident regarding the shock absorbers and springs combo, though, and as far as I know it was developed specifically for the Jimny by Bilstein.
 

For what it's worth I also have a rally background, and there's a huge difference in suspension design compromises between the high speed and the low speed stuff.

For high speed performance, go right ahead and use your polyurethane, the need there is to reduce suspension geometry change, to prevent the unwanted movement that rubber bushes permit. the tradeoff is the additional NVH that you get with poly, and the need to frequently grease to prevent squeaking, take your poly out in the dirt, you end up with contaminated grease, that in turn grinds the cr@p out of the poly, so it's frequent replacement.

Off road, you want the flex, especially in a radius arm suspension design like the coil sprung Jimny - try this when you have the time - remove one of the two bolts that holds the radius arm to the axle, one bolt only, not one on each side, and see how much of a difference there is in the way the suspension flexes in rough terrain.  Poly bushings where the radius arms attach to the axles, no thank you, not on anything I'm driving.

The truth is that the radius arm suspension on the Jimny significantly impacts affects it's ability to articulate, something like a triangulated four link would be waaaay better, but virtually impossible to "package" in a vehicle this compact.

I have poly bushes and get plenty of flex
You can get a 4 link like this for gen3
See these on a lot of jimnys in Japan 
www.hardracesuspension.com.au/suzuki-jim...k-adjustable-arm-kit

That is a pretty interesting kit, I'm curious as to how much of an impact it has on clearance. It is however, not a triangulated four link,

Call me crazy, but I've been mulling the possibility of a rear long arm setup on a five door Jimny, I haven't seen the car yet, ETA here is now May instead of March, I haven't committed to one but I have quite a list of modifications, starting with a long range fuel tank.

The kit allows good articulation from what I have seen 
Usually fitted on suspension lifted Jimny's
I would be guessing a none lifted will suffer clearance issues between upper and lower arm's 

Interesting kit, I guess technically it is a 5 link not a 4. As it is still using the panhard rod for lateral control.

I'd think the biggest issue is unbalancing the vehicle with more rear travel than front. I know this is the only option with anything IFS. But something well balanced front to rear just seems to glide over the terrain nicer IMO.

Just on the cross member brace, most kits offer brackets to lower it for driveline clearance . This makes no sense to me, as you are reducing ground clearance.
Other options include less lowering of the bracket with a curved section removed to increase driveline clearance or the neoplot style that goes over the driveline so has no reduction in clearance.

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