Front Disc Brake Conversion - Check my list please? (1 Viewer)

[JohnJL]

Hi All,
I have read a ton of threads, some of the kits referenced and parts availability seems to have moved on. This is for the front end of a 1974 FJ40 that has 6-spline outer, 30-spline inner axles. Stock knuckles, power steering and big wheels/tires.

I have seen the JToutfitter kit, I want something more Toyota and integrated so I have this plan going on based on comments in other threads.

My goal is to replace the hubs (they are beat up and new ones NLA), better braking with less maintenance, stronger birfields and readily available replacement parts.

I contacted SOR and others, all the kits out there seem based on shipping me a pair of used knuckles/rotors/calipers from a minitruck/FJ60, and then I would have to strip/rebuild/replace everything but the knuckles anyway. So here is my plan, please check if I have any compatibilty issues...retaining stock front 1974 FJ40 front axle housing and differential...

1. NOS FJ60 knuckles. Pricey but I can get them,
2. FJ60 hubs like these Free-Wheel Hub - AISIN I am open to Warns too.

3. Knuckle rebuild kit for FJ60 including upper/lower bearings, shims.
4. FJ60 wheel bearing kit
5. New FJ60 calipers
6. New FJ60 rotors
7. FJ60 birfields 30-spline inner to th stock diff, 30-spline outer to the NOS Aisin hubs above
8. Axel seals
9. Hi-steer FJ60 pitman arm (have power steering and the truck has ~3.5" lift.

Am I missing something? Better suggestions?
Thanks

 

[archie73]

I was going to go with high steer as well, but @Mace convinced me not to go that route. I’m using stock mini truck arms (and disc/knuckles) with fj60 TREs. I have 4” of lift and was told that highsteer would cause more issues than it was worth. Disc upgrade led to me doing a fj60 power steering upgrade as well, as I was changing the linkage anyways to custom lengths. If it’s in the future for your rig, it makes sense to do it at the same time.

 

[Redgrrr]

If I was dead set on new knuckles I’d buy Six shooters, high steer arms and the 25mm lower trunnion caps from marlin crawler.

How much are the NOS Fj60 knuckles? Gotta be comparable to the six shooters...

My thoughts are buy a complete Fj60 front axle. Find one local to you and not on mud. To expensive to ship and pain for the seller so they ask to much...

What do you get?

1. Everything you need!

In some cases if the wheel bearings are good you can get away with a seal kit and trunnion bearings. Don’t buy everything separate it just cost to much money in my opinion and experience.

 

[Redgrrr]

You will also probably have to grind out the inside of the housing the birf rotates in to accommodate the larger birfs.

 

[Redgrrr]

One of these works really well to grind out the inside of the knuckle ball. I bought it at low range off-road if I remember but I saw one for half the price at my local welding supply house after the fact.

 

[reddingcruiser]

You gotta stick your 40 inner axles into the 60 birfs somehow. You'll need Birfield C-clips, unless you plan to use the 'Mar-tack' method.

 

[JohnJL]

I was going to go with high steer as well, but @Mace convinced me not to go that route. I’m using stock mini truck arms (and disc/knuckles) with fj60 TREs. I have 4” of lift and was told that highsteer would cause more issues than it was worth. Disc upgrade led to me doing a fj60 power steering upgrade as well, as I was changing the linkage anyways to custom lengths. If it’s in the future for your rig, it makes sense to do it at the same time.

Thanks for the reply. I already have FJ60 power steering on too.

 

[JohnJL]

If I was dead set on new knuckles I’d buy Six shooters, high steer arms and the 25mm lower trunnion caps from marlin crawler.

How much are the NOS Fj60 knuckles? Gotta be comparable to the six shooters...

My thoughts are buy a complete Fj60 front axle. Find one local to you and not on mud. To expensive to ship and pain for the seller so they ask to much...

What do you get?

1. Everything you need!

In some cases if the wheel bearings are good you can get away with a seal kit and trunnion bearings. Don’t buy everything separate it just cost to much money in my opinion and experience.

Thanks for the reply and 6 shooter suggestions. The problems with buying n axle are 1. I work downtown and even if I knew where an fj60 graveyard was I dont have the time or mobile tools to strip one off a car. 2. As above, just about the only thing I would reuse are the knuckles. Everything else is being replaced down to the bearings. It seems a waste of time money and effort to source a whole axle when all I will keep are the knuckles? Even then I am rebuilding the calipers, which I woould do anyway?

 

[JohnJL]

You gotta stick your 40 inner axles into the 60 birfs somehow. You'll need Birfield C-clips, unless you plan to use the 'Mar-tack' method.

I am back in the office today and dont have the truck in front of me, could you expand on that? Do the inner axles not have a clip or are there certain birfs I need to match the 30-spline inner axles?

Thanks

 

[reddingcruiser]

The c-clip holds the inner axle to the birf, and is destroyed during the removal process. They go on the end of the axle and end up inside the birf, and can be a bit of a PITA to install. Without the clip the end, the axle can slide out of the birf and into the third member. The alternative is to put a tack weld on the axle splines just outside of where they fully engage the side gears in the diff. Basically the inner axle is left to 'float' between the birf and third member. A Marlin Crawler trick, thus Mar-tack. Getting the tack weld in the right spot is very important.

 

[69LC]

The 40 Inner axles will swap into the 60 birfs.

Do some searching about separating birfs and inner axles.

The Martack thing is nice. Do it...

 

[69LC]

If you do find a complete donor 60/2 front, you should be able to recoup some costs by selling the housing, inner axles and 3rd member.

 

[JohnJL]

So someone locally came up with a BJ60 front axle complete, I think that wil provide proper knuckles, calipers, flanges, hubs and birfs, I that a good donor?

Thanks all!

 

[JohnJL]

The c-clip holds the inner axle to the birf, and is destroyed during the removal process. They go on the end of the axle and end up inside the birf, and can be a bit of a PITA to install. Without the clip the end, the axle can slide out of the birf and into the third member. The alternative is to put a tack weld on the axle splines just outside of where they fully engage the side gears in the diff. Basically the inner axle is left to 'float' between the birf and third member. A Marlin Crawler trick, thus Mar-tack. Getting the tack weld in the right spot is very important.

Thanks for elaborating. I am both overconfident and dangerous with my MIG -)

 

[3_puppies]

the short side inner axle does not need to be changed out. it is the same length as a 40.
local axle in Toronto?? could be rusty, buy with caution

 

[69LC]

The housing won’t matter if it’s rusty. If the knuckles, spindles and hubs are serviceable, clean them up and coat the outer stuff with chassis paint.

I have some HD stainless knuckle wiper rings and retainer halves I can send over too if you’re interested. Just prototypes, but they won’t get rusted and flimsy.

I call the west side of MI home, so I know Cruiser rust...

 

[JohnJL]

The housing won’t matter if it’s rusty. If the knuckles, spindles and hubs are serviceable, clean them up and coat the outer stuff with chassis paint.

I have some HD stainless knuckle wiper rings and retainer halves I can send over too if you’re interested. Just prototypes, but they won’t get rusted and flimsy.

I call the west side of MI home, so I know Cruiser rust...

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That would be awesome. Fortunately not a lot of rust, I've owned her and dragged her from Virginia to CT to all over Australia to Toronto over 20 years. In Toronto its been summer-only so no salt on her here. That will change though..I am building her in a way I wont have any guilt taking her out in any weather, including plowing my driveway in the winter.

I will message you my address, thank!