FF 8" Mini axle possible project. (1 Viewer)

[ntsqd]

I'm asking here because I figure most have BT, DT and moved on to stronger stuff.
'88 4rnnr that sees DD use, but would like to flat tow it as a "tow'd" behind our camper. Crawling under it to R&R the drive-shaft is only OK the first two times. Used those up.

So: thinking of building a FF rear axle with locking hubs so that I can just unlock the hubs for towing. The TG front dig kit is NOT an option for several reasons - the most immediate of which is it's an auto trans. It's a fairly sedate looking 4rnnr and I'd like to keep it that way (sort-of build thread). Which means I'm going to have to narrow a housing slightly in order to keep the WMS to WMS dim close to stock. Given that the rear diff assembly is 4.56's on an ARB I'm not too interested in something bigger, don't want to abandon the cost of that diff and really don't need more diff strength.

My questions:
1) Is the Mini LA locking hub the best off the shelf option for this, or is there a locking hub that will bolt to the Mini LA front hubs that is known to be stronger? I know that rear axle service is going to work the locking hubs harder.
2) Say I buy FROR's housing flanges, can I fit them to a stock housing or do they really want either a re-tube or an aftermarket housing?
3) Not sure what my next question should be, but I'm sure it will present itself as this thread progresses.

 

[too tall]

Not sure why you are planning on using for axles but most likely 30 spline if I had to guess. I would think mini truck lockouts with 30 spline chromoly hub gears and fuses would be fine . Probably upgrade the fasteners on the hubs to 7/16 fine while you're at it .That's the setup on the front of my rig and I run 40"stickies. You'll have to get shafts made anyway so that's probably the way I'd do it.
I recently built a toyota camper into 4x4 using the stock dually rear ff axle but swapped out the hubs for 80 series to make it a single wheel regular 6 on 5.5" pattern. It was pretty wide though IIRC but decided to use the 8" in the back because of ease of everything else concerned.I made some sleeves that allowed me to use the 80 series brake package as well. I used a 60 series land cruiser front axle. Happy to send a couple of pics if you want to see any of it. Not sure it'll help?

 

[ferg]

Try looking for a Dolphin motor home rear axle. Usually dual and FF.

 

[ntsqd]

Wouldn't that be rather wide? I'm kind of hoping that by the time I cut off the SF flange and weld on the FF spindle flange that the WMS dimension will fall pretty close to an IFS rear housing WMS dimension.

 

[GLTHFJ60]

Dually axles have a narrower wms than their srw (single rear wheel) counterparts. It's worth a look to verify for sure, more than likely it'll be almost too narrow for you to use. Could widen it though.

 

[Pacer]

I'm asking here because I figure most have BT, DT and moved on to stronger stuff.
'88 4rnnr that sees DD use, but would like to flat tow it as a "tow'd" behind our camper. Crawling under it to R&R the drive-shaft is only OK the first two times. Used those up.

So: thinking of building a FF rear axle with locking hubs so that I can just unlock the hubs for towing. The TG front dig kit is NOT an option for several reasons - the most immediate of which is it's an auto trans. It's a fairly sedate looking 4rnnr and I'd like to keep it that way (sort-of build thread). Which means I'm going to have to narrow a housing slightly in order to keep the WMS to WMS dim close to stock. Given that the rear diff assembly is 4.56's on an ARB I'm not too interested in something bigger, don't want to abandon the cost of that diff and really don't need more diff strength.

My questions:
1) Is the Mini LA locking hub the best off the shelf option for this, or is there a locking hub that will bolt to the Mini LA front hubs that is known to be stronger? I know that rear axle service is going to work the locking hubs harder.
2) Say I buy FROR's housing flanges, can I fit them to a stock housing or do they really want either a re-tube or an aftermarket housing?
3) Not sure what my next question should be, but I'm sure it will present itself as this thread progresses.

I have one, I didn't build it, but I have rebuilt it

 

[ntsqd]

Many miles on it? How is the sealing, does it tend to leak anywhere? How are the rear brakes? They seem like they'd be a bit big for rear brakes at at speed, but would likely be fine fro crawling. I'm thinking to go with the version that has a drum parking brake.

 

[Pacer]

Many miles on it? How is the sealing, does it tend to leak anywhere? How are the rear brakes? They seem like they'd be a bit big for rear brakes at at speed, but would likely be fine fro crawling. I'm thinking to go with the version that has a drum parking brake.

Not many miles.
It is indeed seeping at the seals, because I'm running one of them useless rubber accordion breather caps
Rear brakes are indeed too big and do lock up at speed even with proportioning valve cranked down
I put the parking brake at the back of the tcase, but would not on a DD.

I like the rear lockouts, many have suggested I put drive flanges in there instead. I have yet to flat tow it, but like the idea that I can.

Be careful out there

 

[ntsqd]

The p-brake kit version looks to use a caliper with smaller piston area, so that should help with brake biasing. No idea if it is enough.
Good axle breathing has long been high on my importance list, which odd for a left coaster to be so concerned. We generally don't have water crossings like y'all do in the East. The 4rnnr's rear vent likely needs a step up in hose size because after a several hundred mile run on the highway I see some gear lube weeping out of the ARB system's vent.
I wonder if the better sealant call is Hylomar or Right Stuff? Dunno.....
I know that MISF had no end of troubles with sealing his old Warn FF D44 conversion kit. I don't think that he ever did stop it from at least weeping, but I don't know if he ever tried either of those two specific options.

I find it odd that Toyota goes to some effort to seal the diff lube out of their FF wheel bearings when Dana etc. want the diff lube in those bearings. Looks like FRORF's intent is to follow the Mr. T design logic. With my 60's FF I didn't bother with the inner seal, but unfortunately it didn't get many miles of testing on it before being sold.

Tempting to start ordering parts just to get them in hand for inspection and further decisions....

They're getting hard to find, but for your (@Pacer) rear brake situation you might try finding an "LBS" and installing it in the rear brake plumbing. What it does is slow down the pressure rise in the rear. So in a hard stop the fronts do most of the initial braking and slowly as the weight transfers back onto the rear axle it's rear brakes start to do more work. We used one on a T-100 that had Exploder RDB's on it with no proportioning valve at all and those brakes worked well. They were originally made by Stewart Racing Components (known for the domestic engine coolant pumps), who then sold the product to Dan Press Industries. Who eventually, it appears, went out of business. Now there appears to be a third business making these, but I recently found one on ebay from the Stewart days (for about 1/2 the price of new) and the seller claimed to have more.

 

[Pacer]

Very informative, thank you!

Are you able to discern some of the components on my setup?

Maybe Taco front rotors?
I do not know who made the flange adapters either.

I currently have double piston calipers on the rear and should investigate smaller, single piston calipers.

All of this is in my Trekker build, and the brakes are extremely good all around.

Off to investigate LBS.....

 

[ntsqd]

The adapter plate looks like it could be a FRORF part. I don't know if anyone else has ever made those or not. I have read of guys making their own.
Rotors are likely FJ60 fronts, unless the whole wheel hub & rotor assemblies are IFS Mini-Truck. The "notched" face where the rotor mates to the rear of the wheel hub is ringing bells as significant, but as to what I'm blanking on that info. I'm not as sharp on IDing those, but I'm sure that someone here can. I do recall that there is an early and a late wheel hub and rotor design. I *think* the early has a bolt-on rotor while the late uses different lug studs that retain the rotor.

Years ago I discovered that a '78 & earlier 2WD front calipers are a fixed, 2 piston design. However, their mounting ears look to be too close together to bolt on where a 4WD 4 piston caliper fits and their piston area is not significantly smaller.

 

[too tall]

Those look like 60 series front hubs to me. The adapters look like FROR to me as well. What is your plan for the parking brake? I do have a bent 80 series rear axle housing if you'd like to try the spindles from it. I could cut them off and send them to you. You'd have to find rear hubs and brake brackets but it would allow you to use the 80 series rear brake package which has the smaller callipers and internal e-brake setup inside the hats.
I think if you used a 1993 80 series disk/disk non-abs brake master (which would bolt on) you'd have pretty good brake bias. you could then use a stock-brake cable for your truck which you might have to modify (lengthen or shorten) using Nico sleeves and a press. Just an Idea, interested to see what you come up with. Keep posting here so we can see please.

 

[Pacer]

Those look like 60 series front hubs to me. The adapters look like FROR to me as well. What is your plan for the parking brake? I do have a bent 80 series rear axle housing if you'd like to try the spindles from it. I could cut them off and send them to you. You'd have to find rear hubs and brake brackets but it would allow you to use the 80 series rear brake package which has the smaller callipers and internal e-brake setup inside the hats.
I think if you used a 1993 80 series disk/disk non-abs brake master (which would bolt on) you'd have pretty good brake bias. you could then use a stock-brake cable for your truck which you might have to modify (lengthen or shorten) using Nico sleeves and a press. Just an Idea, interested to see what you come up with. Keep posting here so we can see please.

Good infos there!

 

[ntsqd]

I'm trying to not turn this truck into the un-ending project (I have one of those in an FSB that is currently getting a FF D60 for entirely different reasons), so I'm inclined to buy my way out of that situation if I can buy something close to what I want. I have a LA width complete rear axle that I can use. As I recall FRORF told me that their FF kit widens the track 3" per side. Starting with the LA rear housing drops that down to 1.25" wider per side over the current IFS rear housing. Which means that I either narrow the housing a little more, or I accept it as-is and run a spacer up front and combine that with some late model wheels with more back-space than the period OEM wheels have. Those spacers would be a problem though as I'd only consider spacers made from steel, never, ever aluminum wheel spacers. Which likely means that I'd have to make them. Still not real inclined to go that way even though I'd like to move to a 16" or 17" wheel on this truck.

This is the kit that I'm looking at: Full-Floater Chunks Stock - https://frontrangeoffroadfab.com/full-floater-chunks-stock/

The dually housing is intriguing. Any idea what wheel hubs can be used on them? I don't need rear disc brakes, but I'm not opposed to them at all. I do need a parking brake.
The 80 series spindles are also intriguing, but would likely be a much bigger project. It's an angel/devil thing there, part of me wants to go that way and part of me doesn't. I need to finish the Exploder RDB to FF D60 integration and get it under the Blanc-Oh! before I tackle any of this.

 

[too tall]

The Toyota dually housings use spindles that 80 series hubs fit, if you want to run a single wheel. The Full Floater chunks seem a bit $$$ to me but If you have the time to wait, Maybe it would be the easiest? Are you going to run parking brake ?

 

[ntsqd]

Absolutely will have to have an effective parking brake.

 

[too tall]

The full float chunks seem to use front disks for brakes. Are you thinking a driveline brake or some sort of line lock? Not sure what your plan is but as I said interested to see what you come up with. The 80 series rear spindle/ brake package might seem like more work at this point but the ease of brake setup is one of the reasons I used those pieces on the dually rear I modified.

 

[ntsqd]

The link above is a slightly different critter. The calipers are floating, so not 4WD front calipers (Supra some claim). There is an option for a "Drotor" p-brake, which I take to mean that it has a drum p-brake inside the 'hat' portion of the rotor. Drotor Backing Plate Kit - https://frontrangeoffroadfab.com/drotor-backing-plate-kit/

 

[Pacer]

The link above is a slightly different critter. The calipers are floating, so not 4WD front calipers (Supra some claim). There is an option for a "Drotor" p-brake, which I take to mean that it has a drum p-brake inside the 'hat' portion of the rotor. Drotor Backing Plate Kit - https://frontrangeoffroadfab.com/drotor-backing-plate-kit/

Wow, I learned a lot from both those links above.
I learned that is the axle I have and I learned what a smokin deal I got on my drivetrain

DRotor backing plate appears to be larger than the inside of a rotor hat, but maybe I'm seeing it wrong.

I guess an fzj80 series rear rotor could fit over that.

Spendy, but cool!
There are tricks out there to getting 80 series parking brakes to work

 

[quasi]

another option may be a drivehaft disconnect kit. Coupling - https://www.remcodsc.com/coupling/