Full float fj40 axle build (1 Viewer)

[craptabulous]

i am finally attempting something i always wanted to try and pull off.

I am using an old fj40 semi float axle converted into full float , i want it to match fj60 width as it is going into my fj60 axle swapped fj40.

I started by cutting off the outer flanges with a zip cut, i was happy to find it is a beautifully machined surface measuring 3.075” diameter.

I had some sleeves machined at work to .010 interference and 3.5” outside diameter . I threw them on the bbq to 600f and slid them on the tube with a couple good taps . Once cooled i was happy to see they were still exactly 3.5” . I burned them in with two passes with my little miller 211 .

I have flanges from fror coming in the mail that should slide on in a similar manner .

I have a complete spindle set up from a spare front axle . I plan to use these drive flanges that rcv sent me as an apology for a screw up with my front shafts. So far i have only had to buy the fror flanges and seal holders , once i get them on i will order shafts from rcv . I have an arb for the differential , i still need to find brake calipers as my old front axle was missing them.

I also paid way to much for this hunk of unobtanium

This is a slightly different take on what i have seen . Hopefully it works .

 

[Firemedic831]

I don’t want to ruin your day and take the wind out of your sails but I don’t see the FROR flanges coming anytime soon

 

[craptabulous]

I don’t want to ruin your day and take the wind out of your sails but I don’t see the FROR flanges coming anytime soon

Ya i am honestly expecting a long wait or me giving up again but, i did read on another forum some one got their order within a month back in april. So far communication has been good.

I wish they could get things sorted out , when i ordered my keyed steering arms it took a week and i love the product. They even forgot to include the allen bolts and noticed before i did and sent them to me with an apology letter in the box .

Past experience has been good and bad , one of my orders i cancelled after 6 months and got a refund . The other one was completed quickly.

Unfortunately no one else makes the flanges anymore .

 

[EWheeler]

Ya i am honestly expecting a long wait or me giving up again but, i did read on another forum some one got their order within a month back in april. So far communication has been good.

I wish they could get things sorted out , when i ordered my keyed steering arms it took a week and i love the product. They even forgot to include the allen bolts and noticed before i did and sent them to me with an apology letter in the box .

Past experience has been good and bad , one of my orders i cancelled after 6 months and got a refund . The other one was completed quickly.

Unfortunately no one else makes the flanges anymore .

Lots of ways to skin the cat, but understand wanting to use as many Toyota parts that you can and have on hand. If FROR s***s the bed and cannot get you the parts you need, you could go with unit bearings and weld 3.5"ID unit bearing adapter cups to your current housing...... there would be some research needing to be done to select the right unit bearing that would allow you to get custom shafts made that work with your diff and the unit bearing.

Unit Bearing Pocket

UNIT BEARING POCKET

trail-gear.com

 

[craptabulous]

Lots of ways to skin the cat, but understand wanting to use as many Toyota parts that you can and have on hand. If FROR s***s the bed and cannot get you the parts you need, you could go with unit bearings and weld 3.5"ID unit bearing adapter cups to your current housing...... there would be some research needing to be done to select the right unit bearing that would allow you to get custom shafts made that work with your diff and the unit bearing.

Unit Bearing Pocket

UNIT BEARING POCKET

trail-gear.com

Thats a great alternative, i will look into them further.

This is why i chose to make the ends of my axle 3.5” . Just incase fror doesn’t work it seemed like a better number to work with. Glad to see a good 3.5” o.d tube option.

 

[EWheeler]

Thats a great alternative, i will look into them further.

This is why i chose to make the ends of my axle 3.5” . Just incase fror doesn’t work it seemed like a better number to work with. Glad to see a good 3.5” o.d tube option.

There are many weld-on unit bearing cup options. Busted knuckle off road also sells a bunch of axle builder parts too, more geared for the 1ton crowd. Problem is that the unit bearings all come 8 lug, so a lug conversion will be necessary on them. If you decide to focus research elsewhere, look for the parts to build a full float rear axle, 6 lug, with a custom 9" housing. Lots of folks have done so.....

 

[peesalot]

would oem front drive flanges work ? did they not come on oem fj40's ? I have a set somewhere

 

[craptabulous]

would oem front drive flanges work ? did they not come on oem fj40's ? I have a set somewhere

Drive flanges i have covered , oem would work aswell . What i am in need of is spindle flanges , toyota doesn’t make these .

 

[peesalot]

Ruff Stuff does I think

 

[craptabulous]

There are many weld-on unit bearing cup options. Busted knuckle off road also sells a bunch of axle builder parts too, more geared for the 1ton crowd. Problem is that the unit bearings all come 8 lug, so a lug conversion will be necessary on them. If you decide to focus research elsewhere, look for the parts to build a full float rear axle, 6 lug, with a custom 9" housing. Lots of folks have done so.....

8 lug isn’t really suited for my rig , if it was i would just buy a set of superduty axles and be done with it . In canada i doubt i could convert my rig to 1 tonnes for under 10 k , rims and tires alone would cost me 4000$ minimum. I also drive a super duty every day and hate how it turns in 4wheel drive .

So far i have next to nothing into my axle build , i can re use my semi float arb . If i can get spindle flanges + custom shafts i should be under 1000$ for my axle build . I have never broken a semi float shaft, I'm really just screwing around and seeing if i can build one and how well it works .

Plus my front axle already has an arb , rcv’s fror keyed steering.

My 40 is just a family wheeler that i like to drive on the street . It doesn’t really belong in hardcore corner but i figured an axle build did .

Ruff Stuff does I think

They no longer make them , i asked very nicely if they would and they said no .

 

[Firemedic831]

Thats a great alternative, i will look into them further.

This is why i chose to make the ends of my axle 3.5” . Just incase fror doesn’t work it seemed like a better number to work with. Glad to see a good 3.5” o.d tube option.

You could use the weld in Dana 60 spindles and make it a FF. It’s what I did with the Tundra axle

 

[EWheeler]

8 lug isn’t really suited for my rig , if it was i would just buy a set of superduty axles and be done with it . In canada i doubt i could convert my rig to 1 tonnes for under 10 k , rims and tires alone would cost me 4000$ minimum. I also drive a super duty every day and hate how it turns in 4wheel drive .

So far i have next to nothing into my axle build , i can re use my semi float arb . If i can get spindle flanges + custom shafts i should be under 1000$ for my axle build . I have never broken a semi float shaft, I'm really just screwing around and seeing if i can build one and how well it works .

Plus my front axle already has an arb , rcv’s fror keyed steering.

My 40 is just a family wheeler that i like to drive on the street . It doesn’t really belong in hardcore corner but i figured an axle build did .


They no longer make them , i asked very nicely if they would and they said no .

Wasn't suggesting going 8 lug or 1-ton, just stating that is how unit bearings come that bolt to those weld- on cups (8-lug). I've done a bunch of research on this and just sharing information as an option as it sounds like the FROR route is timely. There are two common unit bearings, 99-04 super duty and 05+ super duty. They use different weld-on cups.....i swear, less than 6 months ago there were commercially avaliable weld-on cups for the 99-04 unit bearings, and I cannot find any. The 05+ unit are considered better, but for your use, the 99-04 units are absolutely fine.

For instance, here is a unit bearing offering in the correct 6 lug pattern:

99-04 Super Duty Unit Bearings - 6 on 5.5 - 35 SPLINE

stan@branikmotorsports.com

branikmotorsports.com

I guess worst case would be buy a rear 99-04 sterling axle and cut off the unit bearing cups? I know its getting cost prohibitive at this point in the discussion after buying the cups, and modified unit bearings/hubs, and not having touched the custom shafts required.

I never did figure out what to do with the drive flanges & outer axle splines/diameter if staying with toyota shafts.

This attached service bulletin from Mark Williams has some good visuals and installation instructions for the unit bearing cups.

Good luck!

 

[craptabulous]

Wasn't suggesting going 8 lug or 1-ton, just stating that is how unit bearings come that bolt to those weld- on cups (8-lug). I've done a bunch of research on this and just sharing information as an option as it sounds like the FROR route is timely. There are two common unit bearings, 99-04 super duty and 05+ super duty. They use different weld-on cups.....i swear, less than 6 months ago there were commercially avaliable weld-on cups for the 99-04 unit bearings, and I cannot find any. The 05+ unit are considered better, but for your use, the 99-04 units are absolutely fine.

For instance, here is a unit bearing offering in the correct 6 lug pattern:

99-04 Super Duty Unit Bearings - 6 on 5.5 - 35 SPLINE

stan@branikmotorsports.com

branikmotorsports.com

I guess worst case would be buy a rear 99-04 sterling axle and cut off the unit bearing cups? I know its getting cost prohibitive at this point in the discussion after buying the cups, and modified unit bearings/hubs, and not having touched the custom shafts required.

I never did figure out what to do with the drive flanges & outer axle splines/diameter if staying with toyota shafts.

This attached service bulletin from Mark Williams has some good visuals and installation instructions for the unit bearing cups.

Good luck!

Awesome info .

I am very against 99-04 unit bearings i never could keep a set in my 2000 superduty , my 2015 still has factory wheel bearings , they are light years ahead .

 

[EWheeler]

Awesome info .

I am very against 99-04 unit bearings i never could keep a set in my 2000 superduty , my 2015 still has factory wheel bearings , they are light years ahead .

I'm sure they would be fine under a 40, but understand the precedent set by bad experience.

Just FYI, the 05+ unit bearings will not accommodate 6x5.5 pattern, as discussed/determined here:

Anyone Make a 6 on 5.5 SD60 Unit Bearing for '05+?

I believe the 6 lug unit bearing Spidertrax makes only fits '04 and older SD knuckles. I'm wondering if anyone makes a 6 lug unit bearing that will fit the '05+ SD60.....

irate4x4.com

 

[EWheeler]

The FROR pieces that you ordered are quite simple. Unless they are protected by patent (which probably doesn't even matter if you're just making them for your own personal use) they'd be pretty easy to reproduce by a competent CNC machinist and 3d CAD designer, albeit they wouldn't be cheap as one-offs.

 

[EWheeler]

Jeezuzs why did it take me this long to land here.... Just find an FZJ80 full float axle and either narrow it or rob the parts and swap them to your housing. Way cheaper.

 

[craptabulous]

Jeezuzs why did it take me this long to land here.... Just find an FZJ80 full float axle and either narrow it or rob the parts and swap them to your housing. Way cheaper.

FF 80 axles are rare in canada , i have seen one for sale in 5 years .

 

[craptabulous]

The FROR pieces that you ordered are quite simple. Unless they are protected by patent (which probably doesn't even matter if you're just making them for your own personal use) they'd be pretty easy to reproduce by a competent CNC machinist and 3d CAD designer, albeit they wouldn't be cheap as one-offs.

I have thought of that , im guessing they would run me around 1000$ in canada .

 

[craptabulous]

So apparently fror is still open and will send you what you asked for . It was a 6 month wait .
Flanges , seal holders , seals and arp hub studs arrived .

I am happy with the parts i received they are good quality and i can continue.

 

[peesalot]

What size axle will fit thru the seal holders.