Full-floating rears: better in practice?

[Cruiserdrew]

Did all US 80's have the full float?

No-The 91-92 did not. There are rare 93-94 that did not. If it had ABS, then it had the fullfloat, but if no ABS it was traditional C-clip and drum brake. All 95-97 (that got the superior and more sophisticated transmission too) were full float.

edit-I see Semlin beat me to it-sorry about the double info.

I personally think Toyota messed up by not sticking with the FF on the 100 series and also going to a different lug number and pattern. One of the really great things about Cruisers was the mix and match aspect to major parts that existed from 1970-1997. Diffs were basically the same, axle shafts the same size, some driveline interchangability, wheels interchange etc. My '84 60 for instance, has '78 FJ40 diffs, wheels off of Mustard Cruiser's FJ40, and my '76 FJ40 has '83 FJ60 knuckles/hubs/birf/brakes-and has an FJ60 short side axle shaft in the rear. The 100 really changed everything and is an entirely new and different vehicle. A great vehicle, and a capable vehicle (I'm not trying to rekindle any debates here on IH8MUD) but different from the traditional Land Cruisers that preceeded it.

 

[LandCruiserPhil]

I for one, don't have a clear understanding of the difference between an SF and FF axle. Anyone have the FSM diagram of a rear SF axle so I can better understand what the difference is?

Thanks,
Rookie2

On a SF set-up the axle bears all the vehicles weight and turns the wheel. On a FF its like a front axle where the weight of the vehicle is carried on the spindle and the axles load is the turning of the tire and no weight of the vehicle.

HTH

 

[Greg B]

Yes the axle is pressed through a plate(bearing retainer) the throught the bearing, it is then clipped or seal surface then clip. then whole assembly is bolted to the axle. Just like Mini and Taco, 4/runners. Will know as soon as christo gets another truck as to thickness of rear axle on 100. compliing info. later robbie

So, in this scenario, the wheel wouldn't come off unless the breakage occurred at the wheel, or at least outside of where the plates are pressed on the axle? If this is the case, then you should be able to drive the vehicle for a short time to get it out of wherever you are. Not saying this is a good thing, but not as bad as first indicated when a c-clip goes and the wheel comes off.

Could an 80 housing be used under a 100 (obviously with some changes to mounts etc.) or are dimensions too different? I'm just wondering if that's a viable alternative. One could look for a locked 80 rear end and thus pick up FF axles and a locker at the same time.

 

[harveya]

Another advantage of FF axles. The bearings are a doddle to do. Just had the pleasure of replacing rear wheel bearings on my Surf (4Runner) which has an SF axle. Bearing stuck fast to the axle had to be ground off after first removing all the balls from the race by grinding out a semi circular grove in the cage. Took 4 hours total.

Cheers
Andy

 

[Big_Moose]

Greg B:

Not really, since the 100 axle housing is wider than the 80 axle housing. The Aussie 105 series is a FF rear axle.

You could convert the 100 series SF to a FF axle.................did this on my 40 SF years ago - expensive mod!

 

[robbie]

Yes the 100 SF axle may stay on or may pull through depending on where the break is and Such.
I have heard of a few Axle studs here in the states but more from the OZ guys.
I personally have seen 3-4 93/94 with rear drums, Have driven a couple.
Toyota still has a full floater in other markets, but not here. Why should they, they market the 100/470 as a luxo vechicle that will (in there minds)may only see a dirt road on that rare day. Profit or cuts in Manifacturing save lots of dollars. It is far cheaper to press on a bearing (in labor) then to assemble and adjust a bearing set. One sealed bearing is cheaper than 2 taper roller bearing, a hardended washer and a special lock system (on the rear). This could save a couple of hundred per unit. same with the 343 series tranny, a cheaper unit that will serve well (the 5 speed is a different unit) it really is about dollars sved per unit and still give the intended customer (Intinal) what they need. I wish toyota allow special order to happen for those that want to wait the time to get what they want not what some corperate guy give the us market. later robbie

 

[mabrodis]

Good points Robbie. I also think the switch from FF to SF with the 100-series is to have longer maint intervals. With the SF, the bearings are lubed with gearlube from the diff, so the entire rearend maint involves draining the diff and filling it, done. That is WAY easier/cheaper than the rearend work on a 80-series FF setup.

I agree it would be cool to be able to special order a few parts like that on newer Cruiser that you'd want...but then I can see how Toyota might shy away from that because with some other companies that ends up with lots of oddball vehicles, wierd combinations that aren't even documented etc. Toyota ofcourse has had extensive special-order capabilities in other parts of the world though...

For those not totally familiar with the differences between a SF and FF, I'll try to explain. With a FF axle the axle shaft is not providing any load carrying capacity at all, it is merely transmitting torque to the wheel. A rough example of this is a bicycle. The rear tire on a bicycle would be a full-floater, the chain would be the axle shaft (very rough idea I know ). If you break the chain or take it off, the tire will not fall off because the tire is held on with a hub with opposing bearings tightened down. The chain/axle is merely providing the torque to turn the tire.

In a traditional C-clip SF axle, the axles actually hold the wheel on. There is a clip which holds the inside end of the axle to the side spider gears in the diff. It's fairly clever how the C-clip works, since to get the C-clip off the axle has to be pushed in, but it can't go in because of a steel block on the center pin of the diff, so works pretty good. An example of this (maybe even rougher ) is a dolly to move furniture. It has a steel shaft with tires attached at each end. If you cut that shaft both tires can slide out. The axle shaft is what is holding those tires in, and (in the case of a vehicle) that axle shaft is also providing the torque to turn them. The key there is that the axle is bearing the weight of the vehicle (through a bearing pressed onto the shaft or into the axle housing if in a vehicle, just like some higher-end funiture dollys would have) AND it is providing the torque to turn the wheels, so the axle is doing double-duty. If that axle breaks (just like cutting the shaft on the dolly) then the axle and wheel (they are attached) can just slide out. Ofcourse on a vehicle only the side that breaks would slide out, not both tires...so my dolly example kinda fails there.

There are variations to where the bearing is on a SF axle. On my '81 FJ40, the bearing is pressed (beaten ) into the housing, then it rides on the axle. In a Toy truck/4Runner I believe the bearing is pressed onto the axle shaft and then the bearing is bolted with other stuff to the housing. That 2nd approach is still a semi-floater because the axle is doing double-duty with weight and torque, however it's FAR better if you break something than what my '81 has, since the axle just cruises out on mine, but they are both SF axles even though one remains far more controlled in the case of a axle breakage. On the style like the Toy truck/4Runners are they do not use C-clips in the diff because the pressed on bearing is providing the side-to-side holding of the axle also, similar in theory to a FF axle, but the axle is still doing double-duty so it's still a SF axle...

Wow, this has gotten long...argh...

 

[Greg B]

Big Moose and Robbie, thanks for the info. I wonder if the SF housing can be converted to FF with 105 parts or would you have to change out the entire housing? Either way, it sounds like big $.

 

[alaskacruiser]

I'll go ahead and respond for Shotts and his 100 here: "mine hasn't broken yet, so who cares?!?"

 

[Greg B]

Mabrodis,
Damn! Great explanation! Thanks!

 

[Big_Moose]

Greg B:

Yes, you could convert the 100 SF to a FF, but you wouldn't need 105 series components. You could use the front spindle out from a 80 front and attach to the 100 SF (since 105 uses the same front end / components). Fairly simple mod, but expensive & permanent. You must cut the 100 axle housing (remove the current bearing / seal), attach a machined "adapter" [needs to hold seal] with alxe bolt circle on the inbound side, and the spindle bolt circle on the outside. This would allow you to run hubs or drive plates. You also need to purchase axles with appropriate splines on both ends, etc.

When I did my '40 conversion years ago it was about $1,000 - new axles, bearings, etc. Cheaper to import a diesel 105 rear axle. The only problem with the stock FF setup (even though rare), but if you bend a stock FF axle housing / spindle.....you must buy a complete axle, since the spindle is part of the actual housing / similar to all Toy FF axles.

HTH

 

[Jim_Chow]

Greg B:

Not really, since the 100 axle housing is wider than the 80 axle housing. The Aussie 105 series is a FF rear axle.

You could convert the 100 series SF to a FF axle.................did this on my 40 SF years ago - expensive mod!

Front Range Offroad makes kits for the Toyota minis/4runners for $700 or so. You need calipers from an 80's supra/celica, dust plate (optional)/spindle/hub from a front axle of a pre '86 toyota truck (live axle), front hub bearings from any pre '96 toyota truck. The way it works, you remove your hold drum/axle/bearing assembly. That gets trashed. Then insert the axles (comes w/ the kit). An adapter plate goes over that and bolts to the 4 axle housing bolts (that held the drum assembly on). Then the spindle bolts to the adapter plate, as does the caliper. The bearings can be from either the live axle or IFS front. After that, everything else is the same. On the axle end goes a C-clip. You can either use a manual locking freehub in the rear (for towing), or FJ80 front axle drive plates. By the time you get all the parts, the conversion is more like $1200-1400. You then might need some kind of brake line pressure valve to adjust the pressure between the front and rear.

If you have the fab resources, I'm sure you could manufacture your own FF kit using the spindle/hub from an 80 series front. Too bad the 100 axles are wider than the 80s. OTOH, you could probably use an 80 FF rear on a new 4Runner/Prado.

 

[semlin]

If you did this to a 100 would you not end up losing traction control and/or ABS?

 

[ChuckB]

Mabrodis,
Damn! Great explanation! Thanks!

Agreed!! It makes much more sense to me now

 

[harveya]

On the style like the Toy truck/4Runners are they do not use C-clips in the diff because the pressed on bearing is providing the side-to-side holding of the axle also, similar in theory to a FF axle, but the axle is still doing double-duty so it's still a SF axle...

Wow, this has gotten long...argh...

Also on the Runner, in theory the wheel, axle should'nt come off in the case of bearing breakage as the bearing is held onto the axle shaft with a bearing collar and a C clip. It would need all of the ball bearings to disintigrate completely for the shaft to pull through the bearing - I know cos to remove the bearing on mine I had to remove the ball bearings completely to get the axle shaft out of the backplate so that I could remove the bearing.

I much prefer FF axles, they may need more maintenance however you could do 10 bearing changes on the FF LC in the time it took to do one side on my Runner.

Cheers
Andy

 

[Jim_Chow]

Also on the Runner, in theory the wheel, axle should'nt come off in the case of bearing breakage as the bearing is held onto the axle shaft with a bearing collar and a C clip. It would need all of the ball bearings to disintigrate completely for the shaft to pull through the bearing - I know cos to remove the bearing on mine I had to remove the ball bearings completely to get the axle shaft out of the backplate so that I could remove the bearing.

I much prefer FF axles, they may need more maintenance however you could do 10 bearing changes on the FF LC in the time it took to do one side on my Runner.

Cheers
Andy

Yep, I think the intention w/ the SF is you never have to change the bearing. I know one guy w/ a '88 Runner w/ 270k mi, original rear axle bearings. Mine are close to 200K mi. Yes, they have lateral play in them, but I've yet to see one fail. I've heard of a few cases where the person cheaped-out and reused the bearing retainer sleeve (costs like $30, FSM says to replace it along w/ the C-clip) and that slipped. Usually, they're pressed-on so tight you have to grind them off the axle.