[Jimny-Maybe]

Am debating buying one of these to tow behind a motorhome. Ideally, it would do some 4WD-ing (as opposed to rock hopping), and I'd like to get a handle on what "basic" mods might be available for these things...

Primarily basic suspension lift, and whether LSD options exist for both ends. I understand that the front diff is a weak point (alloy?), but would think there may be options to swap in steel cased diffs out of other GVs, and - hopefully - either LSDs or (possibly) lockers.

If lockers are unobtanium (or not worth the time/effort), I'd be happy to just consider LSDs...Or even a locker at the rear, and LSD at the front (if that combo is even an option in these.

I have my doubts, as I've searched google for "SQ420 LSD" and the like, and have got 3/5 of...well...not much.

I'm looking at the SQ420 GV as it's an (almost) ideal size and weight to tow behind a motorhome - esp. in an enclosed trailer.

[Gwagensteve]

Plenty of options exist for lockers. LSD’s basically don’t exist.
Correct, with a front locker you’ll want a steel diff.

[Jimny-Maybe]

Gwagensteve wrote:

Plenty of options exist for lockers. LSD’s basically don’t exist.
Correct, with a front locker you’ll want a steel diff.

Thanks for that.

Is there some kind of write-up on the overall "swap"?

i.e. "This is what's needed to install an ARB locker into the (standard?) rear diff. This is the model of steel case diff you will want to put in the front, and this is the (ARB) locker to suit..."?

It would be handy if there were some kind of BOM, so I could start gathering parts over the next little while...

[sideways]

I agree, LSDs are rare and can be eye wateringly expensive. Not that air lockers are cheap, but they are more effective.

I'd just put an air locker in the rear diff and not worry about the alloy front diff. With mild wheeling and mild tyre sizes it's very unlikely you'l hurt it. With the rear locker you wont be getting cross axled and shock loading things or left foot braking to get through, the front diff will have an easier life.

Installing an air locker is very simple, it's hardly any more complicated than fitting any other kind of diff centre. There's plenty of guides on various websites. ARBs kit comes with everything you need except the compressor which of course they also sell separately.

The rear diff is plenty strong enough to be locked for your use, the ring gear is the same size as a Hilux one.

[Jimny-Maybe]

sideways wrote:

I agree, LSDs are rare and can be eye wateringly expensive. Not that air lockers are cheap, but they are more effective.

I'd just put an air locker in the rear diff and not worry about the alloy front diff. With mild wheeling and mild tyre sizes it's very unlikely you'l hurt it. With the rear locker you wont be getting cross axled and shock loading things or left foot braking to get through, the front diff will have an easier life.

Installing an air locker is very simple, it's hardly any more complicated than fitting any other kind of diff centre. There's plenty of guides on various websites. ARBs kit comes with everything you need except the compressor which of course they also sell separately.

The rear diff is plenty strong enough to be locked for your use, the ring gear is the same size as a Hilux one.

Thanks mate, much appreciated!

[Jimny-Maybe]

sideways wrote:

I agree, LSDs are rare and can be eye wateringly expensive. Not that air lockers are cheap, but they are more effective.

I'd just put an air locker in the rear diff and not worry about the alloy front diff. With mild wheeling and mild tyre sizes it's very unlikely you'l hurt it. With the rear locker you wont be getting cross axled and shock loading things or left foot braking to get through, the front diff will have an easier life.

Installing an air locker is very simple, it's hardly any more complicated than fitting any other kind of diff centre. There's plenty of guides on various websites. ARBs kit comes with everything you need except the compressor which of course they also sell separately.

The rear diff is plenty strong enough to be locked for your use, the ring gear is the same size as a Hilux one.

Thanks mate. Much appreciated.

[shakes]

You will fit 225/75/16 tires with some very very minor trimming. wait until after you've driven it for a while to decide if you want lift.

I honestly wouldn't worry about a rear locker. The front has minimal suspension travel and wheels are always off the ground.... Front is where it's needed most.
The other argument against a rear locker is if you do pop an axle, it usually takes out the entire rear diff... front CV's are easy enough to change.

Despite the hate they get, I'm quite happy with an auto locker in the front of mine. Makes the steering slightly heavier and barely impacts the turning circle. You will also need to fit manual hubs for this though. A front locker transforms the car from mediocre, to reasonable in the harder stuff. If you do swap to a steel diff, make sure you also fit the support bush (from bruce )

[ZUZUKI]

Agree with 225/75R16 being the most useful size to run.
SQ420 will be alloy front diff - you don't say if it is a manual or auto, but I would rather have a locker in the rear diff any day over the front.
'Mazing on the different thoughts on issues like this.
I would say 2.0litre (+ auto?) driven like you own it, will be unlikely to bust the front, even with larger, gripper tyres. Having said that, peoples do break these diffs when in earlier, lighter, less powerful 1.6litre Vitara's, so it is possible.
Yes, you can swap in a steel housing & centre from a manual V6, but has 4.3:1 gears, which isn't what you will have = set up costs.
Some of the last auto V6's had a steel front diff & run 4.875:1 gears, which is what you should have as a manual. If you have an auto, should be 5.125:1.
Yes, the front has ordinary travel (along with pretty much all IFS 4WD's), but longer shocks & springs in the rear will give decent travel, & give you decent drive with a locker.
An air locker is $1000, fitting it (by a workshop) should be $350-400, Compressor $300, wiring & plumbing $300 - you are realistically looking at a $2k excersize.
Try a set of M/T's for 1/2 that amount & see if you really need it.
As a touring / mild 4WD (not rockhopping, as you say) there will be few times where a locker is worth having, but if you have the money, go for it.
The P/S/F driveshaft is not too hard to change, but the D/S/F is a PITA at the best of times & there is not a good way of running a P/S in the D/S with a stubby mod, like can be done in a Vitara.

The lightest car is J20manual (I suppose we are talking LWB wagons here?) at 1335kg curb, J20auto is 1375kg & H25 man & auto are both listed at 1405kg which is a bit strange.
The V6 has noticeably more go than the 4cyl, but drinks more fuel. both have 66litre tanks.

OME from ARB is as good a suspension kit as any, although Dobinsons & Pedders have options as well.

Have fun, Rgs, Michael

[Jimny-Maybe]

ZUZUKI wrote:

Agree with 225/75R16 being the most useful size to run.
SQ420 will be alloy front diff - you don't say if it is a manual or auto, but I would rather have a locker in the rear diff any day over the front.
'Mazing on the different thoughts on issues like this.
I would say 2.0litre (+ auto?) driven like you own it, will be unlikely to bust the front, even with larger, gripper tyres. Having said that, peoples do break these diffs when in earlier, lighter, less powerful 1.6litre Vitara's, so it is possible.
Yes, you can swap in a steel housing & centre from a manual V6, but has 4.3:1 gears, which isn't what you will have = set up costs.
Some of the last auto V6's had a steel front diff & run 4.875:1 gears, which is what you should have as a manual. If you have an auto, should be 5.125:1.
Yes, the front has ordinary travel (along with pretty much all IFS 4WD's), but longer shocks & springs in the rear will give decent travel, & give you decent drive with a locker.
An air locker is $1000, fitting it (by a workshop) should be $350-400, Compressor $300, wiring & plumbing $300 - you are realistically looking at a $2k excersize.
Try a set of M/T's for 1/2 that amount & see if you really need it.
As a touring / mild 4WD (not rockhopping, as you say) there will be few times where a locker is worth having, but if you have the money, go for it.
The P/S/F driveshaft is not too hard to change, but the D/S/F is a PITA at the best of times & there is not a good way of running a P/S in the D/S with a stubby mod, like can be done in a Vitara.

The lightest car is J20manual (I suppose we are talking LWB wagons here?) at 1335kg curb, J20auto is 1375kg & H25 man & auto are both listed at 1405kg which is a bit strange.
The V6 has noticeably more go than the 4cyl, but drinks more fuel. both have 66litre tanks.

OME from ARB is as good a suspension kit as any, although Dobinsons & Pedders have options as well.

Have fun, Rgs, Michael

Thanks for that.

Should have mentioned: We are looking for the lightest - and shortest - 4WD we can tow in an enclosed trailer. not because the vehicle we will buy might struggle (it won't), but more for ease of fitment in the trailer, and to leave room to store tools/spares and such.

As such, we were looking (originally) at a Jimny, in manual, and re-powered with an M18A. But the Jimny's, while light etc. are expensive to procure, and then one needs to add the cost and d*cking around of the engine swap on top...So we then started looking at the SWB Vitaras. The one I've been looking at is a 3-door (so SWB) SQ420, with the J20 and manual. (Not sold on Suzuki autos).

In all, it all sounds a bit too hard, and too much f*cking around, for something which will likely not need it the bulk of the time. I guess my thinking (like my thinking generally) was "It's better to have and not need, than to need and not have..." But when it becomes orders of magnitude too difficult/costly to do, perhaps it's time to look at spending money elsewhere...possibly on a different rig.

Appreciate the input.

[Gwagensteve]

I disagree about which end needs a locker also. From my experience, Vitaras vehicles rarely lift front wheels - they'll generally lift a rear wheel as the car follows the nose - the fronts stay well planted until the angles get very serious. The well known problems with front end breakage would steer me away from locking the front. I've seen far too many CV's/housings/pinions fail, even under light use.

[30ONA]

Can anyone shed light on the Val racing Lsd (Russian) ? I got this from them but I know nothing about the diff sizes. They also have a detailed drawing with dimensions.


The inter-wheel differential of increased friction (self-locking differential) is installed in the rear reducer of SUZUKI GRAND VITARA (Suzuki Grand Vitara) cars: it is produced from May 1988 to May 2005.

Attention: in the Suzuki Vitara / Escudo cars, 1988-2005, two types of differentials of the rear axle gearbox can be installed:

1 type: With the landing diameter of the driving pinion of the differential of the main pair is -118 mm.

2nd type: With the landing diameter of the driving pinion of the differential of the main pair - 108 mm.

The VAL-RAYING gearbox production plant produces a self-locking differential with a bore diameter of -118 mm.

[Gwagensteve]

Why do you want an LSD?

[fordem]

The 108/118mm refers to the ID (internal diameter) of the ring gear - all of the Vitaras, and Grand Vitaras up to 2005 should have a 118mm ID ring gear in the rear axle - you can pull your third & measure to confirm.

[sideways]

Looks like it's a ATB style lsd (like a Quaife). Interesting. It would be great for sand but is close to useless once you lift a wheel. Ashcroft LSDs are this style and they are extremely popular in landrover world.

As an aside, I'd love an ATB that also had a selectable locker. Bonus traction all the time without compromising the turning circle and then lock it when you get to wheel lifting terrain.

Looks like the price is right but you aren't that far off the price of a Chinese air locker. Let us know how you go.

[30ONA]

Gwagensteve wrote:

Why do you want an LSD?

Better than an open diff. Good for gravel and slippery surfaces.

[30ONA]

fordem wrote:

The 108/118mm refers to the ID (internal diameter) of the ring gear - all of the Vitaras, and Grand Vitaras up to 2005 should have a 118mm ID ring gear in the rear axle - you can pull your third & measure to confirm.

So should fit. When you say remove third, do you mean drive shaft? I wouldn't know what to measure. I have an SQ420 2004

[Gwagensteve]

30ONA wrote:

Better than an open diff. Good for gravel and slippery surfaces.

Maybe. An effective LSD will improve acceleration out of a corner no doubt, but will substantially increase oversteer, especially if you're cornering close to the limit of adhesion and then accelerate. I guess it depends on your focus, but if the LSD won't drive the car with a wheel in the air, all it's really doing is tuning the driving experience, it's not making much difference to capability.

As sideways points out, they're great for sand though for a completely different reason.

As an aside, I'm finding some "interesting" interactions between stability/traction control and the LSD in my FG ute, especially when the LSD is making the car slide and then the ESC tries to correct the slide.

[fordem]

30ONA wrote:

So should fit. When you say remove third, do you mean drive shaft? I wouldn't know what to measure. I have an SQ420 2004

Third member aka pig aka drop out aka differential carrier - the assembled differential on an SQ420 can be removed from the axle after pulling the axle shafts without disturbing the critical settings - you would be measuring the diameter of the circular body of the differential itself where the ring gear fits over it.

[30ONA]

Thanks Fordem. Still like another language to me though. Maybe someone has one lying around they could measure? I doubt it would be in the service manual but I'll check anyway.

[30ONA]

Gwagensteve wrote:

30ONA wrote:

Better than an open diff. Good for gravel and slippery surfaces.

Maybe. An effective LSD will improve acceleration out of a corner no doubt, but will substantially increase oversteer, especially if you're cornering close to the limit of adhesion and then accelerate. I guess it depends on your focus, but if the LSD won't drive the car with a wheel in the air, all it's really doing is tuning the driving experience, it's not making much difference to capability.

As sideways points out, they're great for sand though for a completely different reason.

As an aside, I'm finding some "interesting" interactions between stability/traction control and the LSD in my FG ute, especially when the LSD is making the car slide and then the ESC tries to correct the slide.

Yeah that makes no sense. I've never appreciated esc. Just lift off. Must be designed for numphies.

[Gwagensteve]

Like any electronic system, it’s all down to the tuning. Apparently Porsche PASM is other-worldly and seems to just work with he driver to get the car to do what you want, some ESC you’ll almost never feel, in some cars it’s incredibly clumsy and intrusive.

I’ve had it intervene in a couple of cars in a way that’s undoubtedly corrected an unintended slide. In the other had, in our GTS R the combination of LSD, torque vectoring and ESC is pretty seamless and the car just feels like it has lots of mechanical grip.