IFS Locker Vs Solid Axel Conversion

[timmay556]

I've currently got an IFS 96 Hilux, Its well maintained so I want to hold on to her. I'm wanting a bit more off-road capability so I'm considering either Locking the front (so when I'm driving round town she's a normal car) or saving for a SAC. What price would I expect to pay for a work shop to do it for me? I know the locker would be about 700$

I guess the SAC would give me much much more in the long term but I'm talking bang for buck. Any guys done the same?

Cheers.

[J_Dub]

"mike" commented recently that he locked the front of his which saved him the need to sas his and saved him from constantly breaking shit

[swampa]

unless you want to do comps or fit tyres above 33's just chuck a locker in the front

[timmay556]

Cheers for the help guys.

Nah I just want to run my 31's.

Do you know what kind of things "mike" was breaking? was it because he was charging hills etc?

[UBZ]

Toyota IFS front suspension setups don't flex much, only about 100mm total.
it means that you are constantly putting a front wheel in the air . A spinning front wheel under torque coming back down and stopping as it hits the ground normally results in a smashed crown wheel in the front diff. Ive done 3 front diffs in my Surf.

Trick is to get off the gas as soon as you put a wheel in the air , but in the heat of the moment ...............

Front locker allows you to crawl over stuff ,so you don't need to hit things with as much speed. You will still break front CV's if you pushing it but these are changeable on the trial.

Not sure if you get a Auto locker for a 96 Hilux Does it have struts or Torsion bars in the front? Might have to be an expensive Air Locker.

[tallsam66]

A good idea is to also put manual hubs in...then you can fully dissconnect the front diff when on the tarseal.
An ADD diff only disconnects 1 side of the diff when in 2wd...so technically you could fit only 1 manual hub.

[mike]

A good idea is to also put manual hubs in...then you can fully dissconnect the front diff when on the tarseal.
An ADD diff only disconnects 1 side of the diff when in 2wd...so technically you could fit only 1 manual hub.

which is what i have done good thing is its only the drivers side you need it, so no walking right around the truck to put the other side - saves heaps of time

only running 31's? cost of locker $700 vs cost of SAS $3k and over and you still dont have a locker and won't get as far as a IFS with front locker

[Steve_t647]

Another thing is you may have to play with the engine sump to allow for the diffhead.

Option 1) You can go coil front end (more expensive) for the ride quality. Have a look at the work Tim (Hosehussler did to his) in Toyota club truck sas, that is a well done coil setup that works.

Option 2) Leaf spring front end (cheaper but you loose a lot of ride quality) take a ride in a older hilux.

Option 3) Put in a locker, if you drive smart you will have a lot more fun go a lot further and put the rest of the money into tyres, fuel and maintanance.

You can change to a SAS later but I would suspect you won't and may add bullbars and a winch...

[timmay556]

Cheers for more opinions guys. My truck has manual hubs already. UBZ cheers for that. I think a front locker is the go as I like my road ride quality!!!!!!

[DieselBoy]

Now this is a question I have always wondered about, having owned a couple of IFS trucks.

The front end is the weak link.

It makes the truck drive really nice on the road compared to the ugly characteristics of a solid axle, but it's not that flash on the gnarly stuff.

In both my current trucks, I have diff locks. I use the rear all the time!!!

I find I almost never need to put the front locker in. Infact, I try not to put the front locker in unless i'm on something really slippery, or I'm crawling it.

Thats because the front axle is the weakest due to the CV joints.

Now, an IFS truck has 4 CV joints.

If you leave the rear open and lock the front, you are 2 times as likely to bust a CV as a solid axle vehicle with the front diff locked.

Also, in an open diff situation, the diff only ever transfers a maximum of 50% of the dive to one of the axles at any one time. Add a diff lock to the equation, and it supplies 100% of the drive to both axles all of the time.

That is again doubling your chances of blowing a CV, and considering there is 4 to blow, thats not good.

Having the front locked also has a considerable negative effect on steering and handeling off road, and also when the hubs are locked and you are in 2wd, you can feel the auto locker racheting through the steering.

If you left the front open, and locked just the rear, in allmost all situations you would be advantaged. Think about where most of the weight is transfered to when tackeling obsticles of road. Its to the rear axle.

This enables you to walk through things that would normally have the vehicle waving wheels in the air spining and doing nothing.

As a result, you don't need to hit stuff hard anymore, which is when the front diff blows, as it lifts a spinning wheel and then comes back down and bites.

If you just locked the rear, your chances of blowing something in the rear in comparison to a Solid axle vehicle is the same.

If it was me, I would lock the rear end and leave the all ready weak front end well alone.

If you really have to, twin lock it like Mike has done.

You must have a selectable locker in the front IMO.

[mike]

You must have a selectable locker in the front IMO.

Disagree IMO, you learn to drive accordingly with an auto locker. Sure having a selectable locker would be nice but its not a must have. hell I dont want a lcoker full stop in the LR and nor did 2's have one in his beast.

Also on the CV's. in 4 years of having the front locked with an auto locker I've never broken a CV just a CV spline and one diff. Sure ive had the rear locked as well but the diff going shows that the CV's dont (in my case) before the weak diff even when locked.

But thats just in my surfs case and with my driving style.

IMO still best thing to do is locker in the front for ifs surfs. save you $$$ in the long run especially as you can use the CV's out of earlier surfs that people are throwing away. Hell i swap out CV's for newer CV's just because the boots are split and throw the CV's out they are that plentiful

[DieselBoy]

Yay for tech disscussion on ORE

You get away with it because you are twin locked

Would hate to see the carnage from just having the front locked!!!!

Think about it like this:

What blows the front diff??

Lots of wheel spin, lifting a wheel, then that wheel coming back down .

That mainly happens when both axles are open.

This is hard to describe.

The front wheels cannot spin faster than the back wheels.

Say you are tackling a cross axle section of track, normally with open diffs you would have to roll the vehicle through it using momentum and the inevitable wheel spin to get through. This is often where the dif goes pop.

With the rear locked, the single rear wheel in contact with the ground takes the whole load of the vehicle and pushes the vehicle through the obsticle.

As that wheel was in contact with the ground, being supplied 100% of the drive, it is impossible for wheel spin to occur over the speed at which that single driving wheel is turning.

That means the front wheels cannot come back down to the ground spinning fast and blow the front diff unless you have both rear wheels doing the same speed. If the wheels were spining at those speeds, you would have bigger things to worry about like flying off the track if its dry, or you were in a slippery situation and unlikely to blow the diff anyway.

Take that same cross axled scenario, and imagine the doing that with the front axle locked and the rear open.

One of the poor little front axles, complete with two CV's, one at each end, is being force fed 100% of the drive plus the entire weight of the vehicle in order to drag it through the obstacle.

I know i would much rather be asking the rear axle to do the hard work and leave the front well alone.

All you are trying to do is prevent having to throw the vehicle at a cross axled situation due to the lack of articultion. A rear locker will prevent this just as well if not better than a front locker.

Locking the rear axle is a much stronger option than just locking the front.

[rokhound]

Couldn't agree with DB more on rear lockers versus front.

But if (using the above scenario) you are cross axled and driving through with the rear axle locked and 1 front wheel waving in the air, that front wheel will get 100% of the drive that is being produced to the front end, which in turn will mean that it will be spining at twice the speed as the rear wheels.

The drive from the transfer case is split 50/50 in a selectable 4wd, and then the drive between left and right hand sides is split 50/50 as well (when all wheels are in contact with the ground) because of the 2 diffs. Now with the rear locked, each rear wheel is getting 50% of the drive supplied to the rear, but if one front wheel is in the air, then that will receive 100% of the drive sent to the front, which will have it spinning faster.

But correct me if I am wrong.

Lockers both ends, or not at all

[DieselBoy]

Nup.

It is physically imposssible when in 4wd for a front wheel to spin faster than a rear wheel. That is why a center diff is necessary for full-time 4wd vehicles in order to differentiate between the font and rear wheels when cornering.

Thats "How does 4wd work 101"

With an open diff, the one axle can only get a maximum of 50% of the drive.

With a locked diff, both axles get 100% of the drive all of the time.

[Heath]

Rokhound is right about the path of least resistance in an unlocked vehicle. 50/50 split front to rear and 50/50 split left to right on solid ground.

In an unlocked axle the split depends on the path of least resistsnce and the wheel with least resistance (one in the air) will spin with almost 100 percent of the drive (it spins at twice the input speed - the other will stay stationary). This is where full time 4wders have to be careful, lift a wheel in full time mode without the centre diff locked and all the driving force is sent down the path of least resistance, 100% to the front diff and then 100% of that to the lifted tyre), it becomes a 1 wheel drive - the lifted one.

In a locked axle the 50/50 split of power/torque/drive (or whatever) is locked and remains constant so both wheels get the same amount of the split (50/50).

But I guess If you are traveling at 5km/h (actuall speed over ground) when a front wheel lifts off and you are maintaining 5km speed then the wheel in contact will continue to turn at its 5km speed and thus the other (lifted) front wheel will do the same (or very close). This lifted wheel although it is the path of least resistance (and in theory gets 100% of the drive to the front), the power has to work through the front differential and the turning of the opposite grounded front wheel works on the differential which slows the raised wheel's rotation.

But if the vehicle for some reason loses forward momentum (loss of traction at the rear end) then the front lifted wheel becomes the path of least resistance, the grounded wheel stops turning and all drive will be sent to lifted wheel.

At first I thought no this cant be right and started to argue against it (deleted that stuff) but then I thought about it a bit more and now My brain hurts .

As long as the vehicle continues to move forward at a rate consistant with the drive from the locked rear axles then the front wheels (even the lifted one) will turn at the same (or very similar) speed. It all changes when the momentum (vehicle speed over ground) and wheel speeds are different.

[mike]

or you could look at it like this. The rear suspension in a surf (coil) is actually very good standard but the front ifs is completely shit. Dropping a wheel more than 50mm is almost unheard of in a lifted ifs truck thus causing wheel spin thus loading the rear axle up and if that rear axle doesnt have a locker then hopefully it has traction to both wheels because all of a sudden due to that tiny wee pot hole the whole vehicles weight is riding on that rear axle and lets say it doesnt have enough grip to get through (before one wheel letting go). Putting the locker in the front will allow the front to play its part and keep drive to the front for that axle and the rear should be flexing enough to keep both wheels on the deck and the vehicle drives through. Sure all load has gone to the driving wheel but this must have happened at least once or twice in mine while climbing out of something etc.

So in DB's case putting the locker in the rear you get one locked axle with good standard suspension travel to keep those wheels on the ground and nothing in the front and a drop of 35mm (in my case) before a wheel comes of the ground, making that drive line useless, or

you have a front locker which gives you a locked axle plus a good performing live axle in the rear trying to keep both wheels on the ground with maybe 4-8" travel.

[smiddy]

tim, like i said before, just buy my truck and you wont have that problem , and besides you will get yourself a SFA and an air locker il even throw in a rear locker

[rangimotors]

other than breaking things you also need to look at which one gives the better off road improvement.
My old surf was forever stuck in holes getting right to the end of them but just couldn't climb up out of them, you never ever see a hole with 2 nice even ruts coming out of it, one side is always much more rutted out with holes and things like tree roots. Now having a welded diff (yes bad plan i know) in the rear helped push the truck through the hole but made next to no difference in getting it to climb up and out of it. The back wheels just sit there still in the mud spinning and the front wheel in the air spins its ass off until the truck rolls back and everything hits the ground again.
I ended up using a front locker and a (piss poor) lsd in the rear, it was a fantastic combo which allowed me to go everywhere that my friend whet in his solid axle hilux (both same tyres and height) until i went with the front locker he pretty much was hooked up to the front of my truck the whole time.
And just as a note I never broke anything in the front even with a locker and 33's, pretty much broke everything else but low ratio 1st was usually plenty to get me up out of a hole.
my 2c

[DieselBoy]

OMG

Seriously, with a locked diff, both axles get 100% of the drive, not 50%.

With an open Diff, the axles only get 50% of the drive, a 50/50 split if you like.

If a front wheel is in the air, it is not spinning a twice the speed of the rear wheels.

The second that both front wheels are back on the ground again it is a 50/50 split of drive.

If the wheel is in the air, it is not providing any drive.

If the diff was locked, the wheel still on the ground would be providing 100% of the drive.

Simple mechanics people

[timmay556]

Cheers for the first hand info there Rangimotors.
Smiddy, your truck is off the road too much for my liking

DieselBoy, how does each wheel get 100%? that means there is 200% at the diff?

[DieselBoy]

Ohhhh never mind

[mike]

oh i was under the impression that if the rear wheels were spinning and the vehicle is stopped and lets say the front left was stopped (like trying to exit a river) and the front right was in the air then through the spider gears (because the diff thinks its turning a crazy ass size circle) it spins the wheel in the air at a far greater speed than if they were both had the same traction or going straight. The slower the front left wheel goes the faster the front right goes. This is if the vehicle is stopped and the rear wheels are spinning and the front left is stopped and the right front is in the air (no traction).

[mike]

ah i see the problem,

db is referring to a different drive than others.
youll need to define your definition of drive.

the way i see it and possibly other 'normal conventional' people is this:

drive is from engine not ground as in db's examples i think.

total drive over hole truck 100% which is divided front and rear axles 50% each. each wheel then gets 25% drive.

open diff one wheel slips then 50% of drive goes out the slipping wheel. locked diff 25% drive is still applied to both wheels.

[rokhound]

Thanks Mike for the clarification. I didn't think it was rocket science either, but apparently simple mechanics is far more complex than rocket science.

The fast spinning wheel in the air is the one that causes the issues when it come back into contact with the ground.

But I definitely agree with DB that a rear locker is shit loads more effective than a front one (if only one is to be employed). So just save the conundrum of which end to fit, and do both. Selectable or auto is another issue that can be researched on Pirate

[timmay556]

ah i see the problem,

db is referring to a different drive than others.
youll need to define your definition of drive.

the way i see it and possibly other 'normal conventional' people is this:

drive is from engine not ground as in db's examples i think.

total drive over hole truck 100% which is divided front and rear axles 50% each. each wheel then gets 25% drive.

open diff one wheel slips then 50% of drive goes out the slipping wheel. locked diff 25% drive is still applied to both wheels.

ahhh yes thanks for clearing that up!!!!

[Heath]

Thanks Mike for the clarification. I didn't think it was rocket science either, but apparently simple mechanics is far more complex than rocket science.

The fast spinning wheel in the air is the one that causes the issues when it come back into contact with the ground.

But I definitely agree with DB that a rear locker is shit loads more effective than a front one (if only one is to be employed). So just save the conundrum of which end to fit, and do both. Selectable or auto is another issue that can be researched on Pirate

Ohhh thats mean . Sending the poor guy in to the pirate forum to ask a question. Hell if he comes back slightly singed He will be lucky, but more likely flamed to hell and back.

But seriously pirate has heaps of info, just for your own sake use the search facility before asking a question - they can be nasty.

[rokhound]

Oh yeah. But that's why I said researched. You don't just go in blind on Pirate with questions that have been answered or hammered out a thousand times before.
Gotta love the fact that there is no PC bullshit there though, and if you are prone to having a cry when someone bags you, it is not the place to be

But if I was to answer the original question posted on this thread, I would say lock up the IFS.
If you are quite proficient with fabrication tools and techniques and enjoy the fab side, then do the SAS.

[DieselBoy]

True, in answer to the original post, I would say leave it open/alone and lock the rear instead

[Heath]

I'm running open on both ends of my IFS prado and will be locking up both ends (starting with the rear if funds prove to be in short supply) as they are both a little too prone to damage for my liking. And I like walking slowly through hazards - should have been a rock hopper I guess, but my back is too stuffed for any of that "FUN"

So back on target, lock the rear first gets my vote, takes the strain off the front, but if you are determined to do the front then go for it.

When they wire up air lockers they always seem to do it so the rear is locked before the front can be locked so that must say something.

[Sadam_Husain]

When they wire up air lockers they always seem to do it so the rear is locked before the front can be locked so that must say something.

Thats what the wiring diagram tells you to do but you common the feeds up so you can switch them inderpendantly