FJ40/60 factory machined surfaces to mount & align FF/Disc Flanges

[abosely]

Thought I'd go ahead and post up about using an FJ40 or FJ60 rear axle housings machined surfaces to mount Ruff Stuff FF/Disc flanges and having a range of WMS to WMS widths.

FJ60 rear drum brake housing flange.

Grind the weld.

This is what we have. It's 3.970" OD and 2-3/16" from end of housing to end of machined area, the step is 1/2" long and .140" thick and the thickness past the 1/2" step is .170" thick.

This is where the sleeve will go, it will only be about an inch long on each side.

The inside dia. is 2.770
In the inside view can see it's machined off center, but the machined surfaces are parallel & in alignment.

Will use pair of Ruff Stuff's FF/Disc flanges. The ears are for the Mini truck?FJ60 calipers to bolt to.

I'll break this up in couple posts.

Allen

 

[abosely]

The problem or complication with using Ruff Stuff FF/Disc flanges on a LC axle housing instead of a DOM tubed housing is that the LC housing is oval not round and has two welded seams down the front and back of the tubes.

But if you cut the factory drum brake flanges off, now we have two factory machined surfaces, lined up and parallel.

For my build I want the rear WMS to WMS to be 59-1/2" and there is plenty of room on the machined housing ends that a FJ60 housing can be anywhere from about 57-1/2" to 63", using an FJ40 rear axle housing the width range will be 2" shorter than what would be using an FJ60 housing. My 74' FJ40 & 87" FH60 are the same except the 40 is 2" shorter outside to outside housing width.

I went with the FJ60 housing because it's in slightly nicer condition and at 59-1/2" the thinner 1/2" of the tube will be cut off, though with end it really wouldn't matter.

OK about the sleeving. Since the outside and the inside of the last two inches or so thin, getting two pieces of 3-1/2"x 1/4" DOM and opening them up to a snug fit over the machined ends of the tubes the length needed, welding to tube where old weld was and on end of tube. The using RS flanges for 3-1/2" tubes to weld on.

For axle seals going to use the method J Mack used on his FF rear build. Not use the brass bushings in the spindles but machine out the inside of the spindle to accept Marlin Crawler Eco Seals and use Chromoly Spindles.

This is J Macks pic of one of his.

I'm not used to measuring in thousandths (I'm a wood butcher) so where I screw up my dimensions don't laugh, just help me correct them

Allen

 

[handcannon]

I'm interested in this axle mod. I have lots of questions, which is why I'm following all the FF build threads I find. Please do post lots of pics, and lots of tech about this. Don't know that I will ever have the money to do this, but I have been a fan of FF axles for a very long time, ever since my first 3/4 ton pickup back in the 70's.

So, you are a wood butcher? About halfway through my senior year of high school I started working half time in a cabinet shop. Went through the three year apprenticeship, and have been working with wood in some form or another ever since, until a forced retirement almost seven years ago.

Don

 

[abosely]

I like lots of pics, measurements data on tech type things. But I worry I'll make it to detailed and bore people to tears!

The neat thing about this conversion is that it's not really an expensive conversion to do. Well. I guess the parking brake does add a bit more cost. The TSM disc parking brake adds $300 and the B1000 10.5" Lay Down Ratchet Parking Brake Lever adds about $50.

The RS FF/Disc flanges are $195, need pair of FJ60 front calipers & vented discs, pair of marlin EcoSeals $18 new spindle/hub bearings scrounge up a set of used spindles & hubs and set of double splined axles, & drive flange or locking hubs.

One nice thing too is parts can be gathered up over time so it's not a big chunk of $ out of pocket all at once. Watch for Ruff Stuff to have a sale & save a good bit there.

But I hear ya tho, I'm building mine on a thread of a shoestring budget! lol Went through a pretty big finical reversal few years ago.

Thankfully Land Cruisers can be build piece at a time!

Yea, I enjoy working with wood still.

Allen

 

[pjohnson]

Can you provide some details (and pics?) on removing the old flanges?

 

[abosely]

Sure, I used a 6"x1/4" grinding disc because that's what I had left at the time. Started grinding on the weld right up against the flange, like was going to cut it off, worked my way around it making a groove to follow and ground down to where I thought the weld stopped, then angled the disc so it looked like it was undercutting the flange a little.
It's only welded on the inside of the flange.

After I had it to where I thought I had ground the weld to the housing tube, took a 3lb hammer and beat in the ears of the flange and looked for a part line in the groove. It seemed like it was wanting to let go but was still tight so ground a groove all the way around the flange like this, but not all the way thru. It seemed to relive some pressure or grip on the tube and after hitting around the flange it started to move, squirted some Liquid Wrench in the groove and on end of tube and it slide right off.

On this pic you can see placed where I had hit it with hammer in a few places before deciding to cut a second groove.

The other side I did a little differently, after grinding the groove through the weld all the way around, I cut between the ears 90 degrees about 2/3 the way through the flange and that worked just as well but was less grinding.

Probably too 20-25 mins grinding for each side, a little less on the second one. Though the 1/4" disk cut a little slower than a thin one being thicker made it stiffer and removed more material to let things relax. A thin blade might tend to bind and break more easily.

This is the 87' FJ60 flange.

Allen

 

[abosely]

This is the 74' FJ40 flange.

It's shaped differently, but the weld is on the inside (toward center) like the FJ60.

From what I could tell, measuring everything, the housing ends are the same on the 40 & 60, but the flanges are shaped and oriented differently.

The FJ40 housing is 53" end to end and the FJ60 is 55" end to end.

Allen

 

[handcannon]

Do you have a guesstimate as to what the WMS to WMS will end up being by going this route? What about new axle shaft lengths? Can this be done in such a way as to be able to use off the shelf axles? Aren't custom axles more expensive that stock sizes?

As you can see I haven't got much in the way of prices for custom parts.

Don

 

[abosely]

Do you have a guesstimate as to what the WMS to WMS will end up being by going this route? What about new axle shaft lengths? Can this be done in such a way as to be able to use off the shelf axles? Aren't custom axles more expensive that stock sizes?

As you can see I haven't got much in the way of prices for custom parts.

Don

Using FJ40 rear housing the WMS to WMS can be from 55-¾" to 59".

If using a FJ60 rear housing the WMS to WMS can be between 57-¾" to 61".

Meaning you can have a WMS to WMS anywhere from 55-¾" up to 61". Use a 40 housing if you want a width between 55-¾" up to 59" and a 60 housing if you want from 57-¾" up to 61".

I'm using a FJ60 housing because it's in nicer shape than the FJ40 housing I have, for a WMS to WMS 58-½", but could use the FJ40 housing to get the 58-½ " width if wanted also.

I'm using the FJ60 front housing since its in as good of shape as the FJ40 housing and will only need one of @lcwizards sleeves on the short side for a WMS to WMS of 61-½" instead of two, one on short side and one on long side the same width.

Allen

 

[abosely]

Made some progress on the housings. Spend some quality time on the rear housing with cutting discs, grinding discs and flap discs.
Tried wire cup but didn't work as well as the flap discs. After the brackets and perches were cut off and ground down, started with 4.5" 36 grit flap disc then worked up with 40, 80 & 120 grit. Cleaned the slag & lumpy bits of welds.

Will sand blast it soon as I get compressor back on line to clean the little nooks & crannies the discs couldn't reach and even out the surface finish. There are a few places I will go over the welds aren't quite ideal when it's in a jig to hold it straight, mostly just small spots, tho one of the seams can use a little bit of attention with the welder.

This is the front housing, but this is what the rear looked like before starting on it, I had cut a few brackets off the front a few days ago already.

Here's the rear housing now, for sand blasting welding.

Here's one of the seams that I'll touch up with welder.

Putting a truss on the long side and a piece of 3.5"x.250 DOM under the Ruff Stuff spring under perches (the ones for 3.5" tubes) to strengthen the tube under and around the spring perches, welding on Ruff Stuff diff guard and forming and welding a 1/4" piece of plate to top and bottom of center, cut hole for drain plug and the guard to come through and weld around it.

This is to give a little more protection to the bottom of the center when dragged over lava rock and add some strength to the center top & bottom, especially since there is a little pitting on the top of the center.

Cut the knuckles and the sheet metal diff cover (welding on a Ruff Stuff diff cover) of the front housing yesterday Have some more grinding to get the old diff cover welded flange
off. Not using the knuckles (too rusted) made it easier, cut around them and hit with 3lb hammer, slid right out. Was pretty pleased they came off so easily, after reading how difficult some are to remove.

Allen

 

[pjohnson]

Thanks for the additional detail on removing the flanges. I'm already committed to an FZJ80 FF rear, but I have an extra 40 rear laying around I might play with.