Why did Toyota use a full float?

[LCSA]

I know it’s been discussed here in detail as to the merits of the full float rear in our 80s, but I haven’t seen any discussion as to why Toyota put a FF in the 80. I’d be interested to learn why? I realize we may never know, but if any one has some insight, I’d love to hear your thoughts!

Was this a parts bin decision (since I assume the axle is shared with the 70), or was this a marketing play, for increased payload/towing numbers? Or another reason altogether?

thanks!

 

[cruisermatt]

Because it’s better

 

[leonard_nemoy]

Because they came with an e-locker. Having the rear locker engaged will put more stress on the axle. The full float does a better job of handling the extra stress and also makes it much easier to remove a broken axle and either repair it in the field or limp along in front wheel drive.

 

[LCSA]

Because they came with an e-locker. Having the rear locker engaged will put more stress on the axle. The full float does a better job of handling the extra stress and also makes it much easier to remove a broken axle and either repair it in the field or limp along in front wheel drive.

Which makes sense to me but nowadays the 4runners, tacos, etc. have a semi-float rear e locker. Were the semi-floats in the 90s not capable enough to handle the locker? I’m pretty sure even the third gen 4runners were running locked semi floats in the late 90s tho.

 

[Road Apple]

Because it’s better

@cruisermatt...can you please explain why the full float is better? Thanks

 

[jonheld]

IIRC, it was the US market that received the semi-float rears. The Australians had FF rears since the 40 Series.
@Onur would be the one to ask about the history, but as to the "why", I'm not sure anyone outside of Araco would know the reasoning.

 

[bigredmachine]

explain why the full float is better?

in a full float rear the weight is supported by the bearings and hubs of the vehicles, the axle shaft dosnt support any weight of the vehicle. ff axle the bearings are not pressed on and it is considered a heavy duty rear.

semi float the weight is supported by the bearings and axle. bearings are pressed on to the axle shaft in a semi float application and it can still be a strong set up but not as strong as a full float set up

 

[ppc]

If a Full Float axle were to fail, the axle can be removed and the vehicle can still be driven.
If a Semi Float axle were to fail, the tire wheel assembly will no longer be secured, the vehicle will be no longer driveable.

 

[flintknapper]

in a full float rear the weight is supported by the bearings and hubs of the vehicles, the axle shaft dosnt support any weight of the vehicle. ff axle the bearings are not pressed on and it is considered a heavy duty rear.

semi float the weight is supported by the bearings and axle. bearings are pressed on to the axle shaft in a semi float application and it can still be a strong set up but not as strong as a full float set up

Close. With a full floater the weight is ultimately borne by the spindle/hub depending on design. In both cases ....none by the axle-shaft itself.... who's only duty it is to transfer torque to the hub.

 

[leonard_nemoy]

Which makes sense to me but nowadays the 4runners, tacos, etc. have a semi-float rear e locker. Were the semi-floats in the 90s not capable enough to handle the locker? I’m pretty sure even the third gen 4runners were running locked semi floats in the late 90s tho.

I would bet the only reason boils down to Toyota having to make the decision. Land cruisers are the gold standard for offroad ability and reliability for Toyota. In the 80's (when the fj80 was designed) emissions were not as big of a hurdle for Toyota to overcome in order to import and sell a vehicle in the USA. Fast forward ten years and I bet Toyota had decided that people didn't need the reliability of the full float in the USA and they decided to sacrifice the full float in favor of the semi-float in the name of fuel efficiency due to weight comparison between the two. Or maybe the semi-float is just cheaper for Toyota.

These are just my guesses..... I wonder if the hilux trucks and other non land cruiser Toyota 4x4's in other parts of the world are also semi-float. I would guess they are full float instead.

 

[LCSA]

I would bet the only reason boils down to Toyota having to make the decision. Land cruisers are the gold standard for offroad ability and reliability for Toyota. In the 80's (when the fj80 was designed) emissions were not as big of a hurdle for Toyota to overcome in order to import and sell a vehicle in the USA. Fast forward ten years and I bet Toyota had decided that people didn't need the reliability of the full float in the USA and they decided to sacrifice the full float in favor of the semi-float in the name of fuel efficiency due to weight comparison between the two. Or maybe the semi-float is just cheaper for Toyota.

These are just my guesses..... I wonder if the hilux trucks and other non land cruiser Toyota 4x4's in other parts of the world are also semi-float. I would guess they are full float instead.

Which makes sense to me but wouldn’t fully explain why the 60 had semi-floating

 

[leonard_nemoy]

Which makes sense to me but wouldn’t fully explain why the 60 had semi-floating

Just guessing again but maybe because the 60 series had leaf springs vs coil spring and no factory locker option in the USA. Leaf springs are better for towing. Even new domestic diesel pick ups still come with leaf springs... I would bet that non US spec 60 series with factory lockers also came with full float axles.

 

[leonard_nemoy]

Which makes sense to me but wouldn’t fully explain why the 60 had semi-floating

Just guessing again but maybe because the 60 series had leaf springs vs coil spring and no factory locker option in the USA. Leaf springs and full floaters are better for towing. Even new domestic diesel pick-ups still come with leaf springs... I would bet that non US spec 60 series with factory lockers also came with full floaters.

 

[cruisermatt]

the real question is why do the full-floaters (and front hubs too) use such tiny hub hardware and silly cone washers that just snap off when you floor it

 

[Feistl]

The cone washer system actually works really well PROVIDING you know how to service them. The issue is the thick headed monkeys with sledge hammers who have no idea what their doing who smash the hubs trying to pop the cone washers out....

The heavy blows damage the face making it no longer perfectly flat, meaning the load is transferred into 1 or 2 studs instead of all 6, hence leading to failure.

Also, being here in Australia I’ve never seen a landcruiser with semi float axles (and I’ve seen/own a lot of em)

 

[cahill]

the real question is why do the full-floaters (and front hubs too) use such tiny hub hardware and silly cone washers that just snap off when you floor it

Try doing that with a stock 1fze instead of the ls you've swapped in there. If you are snapping them when flooring the stock motor than I need to figure out what maintenance you have done so I can get back to that level of performance.

 

[cruisermatt]

The cone washer system actually works really well PROVIDING you know how to service them. The issue is the thick headed monkeys with sledge hammers who have no idea what their doing who smash the hubs trying to pop the cone washers out....

The heavy blows damage the face making it no longer perfectly flat, meaning the load is transferred into 1 or 2 studs instead of all 6, hence leading to failure.

Also, being here in Australia I’ve never seen a landcruiser with semi float axles (and I’ve seen/own a lot of em)

Yeah, I have no idea what I'm doing
Cone washers for the lose. You don't see then on any other axle. Best mod i did to my FF was getting rid of them

 

[Feistl]

Yeah, I have no idea what I'm doing
Cone washers for the lose. You don't see then on any other axle. Best mod i did to my FF was getting rid of them

All I’m saying is 99% of the problem with cone washers is down to damage caused by people who don’t know how to service them (may have been a previous owner). If you remove the hub and axle and fix them up on a lathe (machining both surfaces perfectly flat) AND torque them to the correct value (and check at every service) the system works really well. Like most things, if not treated properly they become problematic and develop a poor reputation...

 

[relaxedcruiser]

X2 for the cone washers .... if worked with correctly they are good. Can be a pia though when rust had found it's way ....
Also never really understood the tiny M8 studs on those hubs - a part definitely designed better on all the Landrover FF hubs .....they have 3/8 UNF or later M10 bolts which are strong enough without cone washers. Their floating drive members are a different story though.....
My JDM sixtie has a full floater rear and for me that would be the standard setup on the various cruisers - while the semi float being the cheap option.

 

[Flight2k5]

Which makes sense to me but wouldn’t fully explain why the 60 had semi-floating

and the 55 and the 40