Leaf spring pack over vs. under the differential

[isketi]

What are the advantages/disadvantages of having the rear leaf spring pack over vs. under the differential?

Over
Strada:


Hilux:


Under
D-Max:

[Automahn]

I guess we can eliminate ride quality as one difference between the 2 set-ups. The Strada was touted as having a comfortable ride compared to all the other Japanese pick-ups in the market today, as reported by our fellow tsikoteers who testdrove it, and it has an over the diff spring set-up while the Hilux has the same over the diff set-up but has a stiff ride.

[kiper]

Ang alam ko para tumaas din ung clearance from the axle to the body. Para pwede maglagay ng bigger wheels and tires when increasing ground clearance.




[SIZE="1"]Because of the mechanical nature of suspension, all sorts of mods are available. Lifting suspension is a popular mod used to try to increase ground clearance. This is often a source of misunderstanding. A lift kit doesn't really give you more ground clearance. What it does is increase the height between the axle and the underside of the body. Whilst this does give more ground clearance for the bodywork, the lowest point on the vehicle is still the axles - or on a 4-wheel-drive, the bottom of the transfer case. For this reason, you'll often see trucks and SUVs with lift kits and larger wheels and tyres. The lift kit boosts the clearance under the bodywork whilst the larger wheels and tyres result in the axles being lifted higher off the ground. Technically of course, in a 4-wheel-drive, you don't really need a lift kit - bigger wheels and tyres would do it. BUT lift kits typically end up being required because adding on the larger wheels and tyres can often mean they will no longer fit in the wheel arches. The lift kit will help solve that problem.

Lift kits come in literally hundreds of shapes and sizes, all dependent on the final application as well as the design of the vehicle the kit is going to be used on. For street cars, typically with independent suspension, the kit will basically be longer struts, longer springs and remounted shocks. For off-roaders with beam axles and transfer cases, the suspension system is typically leaf-spring, so the kit will be a set of blocks that fit between the beam axle and the bottom of the leaf spring. Alternatively, some kits have blocks which lower the spring mounts themselves so that the spring-to-axle joint isn't changed. The image below shows an example of a typical leaf-spring beam-axle suspension system along with two examples of how it can be raised.[/SIZE]

[larshell]

Npansin ko sa pics mas madami palang dahon yong leaf spring ng DMAX compare sa strada. 7pcs yong sa Dmax, 5 lang yong sa Strada at auxiliary nalang yong isa.Walang Hanger yong Hi-LUX yong shackle nakatusok sa frame.
Kaya pala mas mababa ang Dmax kasi yon leafspring nya under difrential.
Mas ok yong strada kasi mas malambot yong set-up na leafspring nya. IMHO

[Memphis Raines]

Npansin ko sa pics mas madami palang dahon yong leaf spring ng DMAX compare sa strada. 7pcs yong sa Dmax, 5 lang yong sa Strada at auxiliary nalang yong isa.Walang Hanger yong Hi-LUX yong shackle nakatusok sa frame.
Kaya pala mas mababa ang Dmax kasi yon leafspring nya under difrential.
Mas ok yong strada kasi mas malambot yong set-up na leafspring nya. IMHO

Actually ang mga 2006 release na Dmax 5 dahon nalang but still medyo matagtag pa rin. May nakapagsabi rin sakin na ang 2006 na Dmax is a bit taller than the '05.

Do you guys have any feedback on Rancho Shocks on pick-ups?

[jarhead]

it also vary on the load limit of the cargo of the vehicle... 1 ton ang sa dmax and hi lux... kaya matagtag ang ride kc matigas masyado ang leafspring niya... dont know lang the load limit cargo ng strada.... and wala naman masydo difference kung nakapatong or not yung leafspring sa diff... 1 thing for sure is tru.. ground clearance ... mataas ang ground clearance ng differential if the leafspring is underneath the diff like the dmax...

[jarhead]

Npansin ko sa pics mas madami palang dahon yong leaf spring ng DMAX compare sa strada. 7pcs yong sa Dmax, 5 lang yong sa Strada at auxiliary nalang yong isa.Walang Hanger yong Hi-LUX yong shackle nakatusok sa frame.
Kaya pala mas mababa ang Dmax kasi yon leafspring nya under difrential.
Mas ok yong strada kasi mas malambot yong set-up na leafspring nya. IMHO

the very 1st dmax that was sold dito sa pinas has the 7 leafspring because it has a 1.5 ton load capacity.. which makes for a very matagtag na ride but they reduced it to 5 leafsprings like the 2004 dmax which we bought... then the newer ones was even more modified like of MEMPHIS RAINES dmax which has the flex ride suspension but still has the 1 ton capacity....

[OTEP]

Spring-over-axle suspensions (the leaves are on top of the axle) is the preferred suspension set up for off-roaders because.
1. It lifts the body higher and out of harm's way
2. It makes further lifting easier (just add leaves, a lift block, or a thicker spring set).
3. It puts the leafsprings higher and out of harm's way. The diff with its rounder shape can more easily slip through terrain where the spring pack can drag. If conditions demand, the diff can also be easily armored.

As for ride quality, it doesn't really matter whether its spring over or spring under. It stil boils down to suspension tuning.

[cocoy]

i guess the first Dmax released here was CBU from thailand, thats probably why they had 7 leaf spring, because in thailand they do use the DMAx for the purpose it was designd for, which is to carry heavy loads to the market. but here it just takes family to the mall, so i guess thats why they had to reduce the leafsprings....sir otep are they bringing the 3.0 liter strada here?

[OTEP]

AFAIK, the next engine after the 2.5Di-D is the 4m41 3.2Di-D also used in the Pajero.

It is still up in the air whether Mitsu will release it. Chance are they will but only after the new Ranger goes on the market.

It makes 165hp and 351Nm. The Ranger Duratorq is still king of the hill in the power race with 380Nm of torque, however.

[redorange]

Are the leaf spring pics all for 4x4's? Typically a 4x2 variant will have a spring under(unless it's a pre-runner version) and the 4x4 will have the spring over suspension(except most SUV's). Although they are both leaf spring suspension there is a still a difference in the ride. The spring under will not be as bouncy as the spring over because it does not need stiffer leafs to deal with axle wrap. Axle wrap(spring wrap) is a problem with the spring over design because of the torque generated at the axle that causes the leafs to twist into a horizontal "S" shape instead of that flattened "U" shape it is originally. If you have a spring under and convert to a spring over without using stiffer leafs you'll get axle wrap as a result.

[Memphis Raines]

As for ride quality, it doesn't really matter whether its spring over or spring under. It stil boils down to suspension tuning.

sir otep, you mentioned that the safe choice for shocks would be OME over the Rancho5000. May naka comment po sakin na mas malambot nga OME but medyo too much daw because there is tendency for increased body rolling, even in braking. What do you think?

Im trying to tune my suspension for a good compromise for my Dmax.

[BoEinG_747]

Hilux:

parang masyado yata malapit ang bolt doon sa spare tire

[jarhead]

i guess the first Dmax released here was CBU from thailand, thats probably why they had 7 leaf spring, because in thailand they do use the DMAx for the purpose it was designd for, which is to carry heavy loads to the market. but here it just takes family to the mall, so i guess thats why they had to reduce the leafsprings....

til now the DMAX is still a CBU from thailand.... basta LS lang ang tatak niya.. The LX was introduced na philipines assembled but didnt pick up sa market. so they revert back to importing the thailand model....

[cocoy]

ah ok, thanks for the info.. do you know when they will bring the new facelifted DMax here with CRDi and VGT turbo?

[larshell]

As for ride quality, it doesn't really matter whether its spring over or spring under. It stil boils down to suspension tuning.

Hindi ba nakakatulong kung yong leafspring ay under differential kahit na maliit na percent lang sa paglambot ng ride? Totally wala talagang ipekto?

[OTEP]

Yung Nissan Frontier 4x2 ng pinsan ko, spring under pero sobrang tagtag. Yung Hilux spring-over pero hindi nalalayo sa tagtag ng Frontier.

Yung Strada spring over pero ang sarap ng ride. Yung DMax din sa spring under, ok ang ride.

So for me, kahit alin yung basic design ay pwedeng gawing matagtag or malambot depende sa tuning ng manufacturer.

[Djerms]

Yup depende na nga yan sa Manufacturer. Dapat alamin nila ang sikreto ng Strada. Btw, how heavy ang load capacity nd strada? Baka naman mababa...

[larshell]

Ok, Ang tagal kung inakala na may kinalaman yong under or over sa lambot ng ride. Kung sa bagay kung tatlo lang ang dahon kahit over or under yan malamang malabot yan.

[OTEP]

Strada GLS A/T's curb weight is 1860kg, Gross Weight is 2570kb. Menos mo na lang weight ng passengers. Do the math. hehehe.