So I've been told to look on this site for a knuckle swap for disc brake conversion on my 64 fj, looking at what I can find nobody's done it or they use a newer axle to swap in it. The housing is fine but I would like to know how to swap the knuckles over off of a ifs mini truck. Also can I put a fine spline pinion in it with birf axles instead of ball and claw. It's by no means a wheeling rig just a nice fj with modern brakes
You will probably have to swap out the diff if I remember correctly, that era should have course spline inners as well….i think most people swap the whole axle simply because its easier that pulling the diff and knuckles ext apart on the truck when you could just roll and old axle out and roll and newer disc brake axle under it and be done.
that link is a really good link for the mini truck swap…should be able to get part numbers ect in some of the threads, personally I am partial to the 60 series swap mostly because thats what is most easily available to me
So I've been told to look on this site for a knuckle swap for disc brake conversion on my 64 fj, looking at what I can find nobody's done it or they use a newer axle to swap in it. The housing is fine but I would like to know how to swap the knuckles over off of a ifs mini truck. Also can I put a fine spline pinion in it with birf axles instead of ball and claw. It's by no means a wheeling rig just a nice fj with modern brakes
I think the issue is that the ball-and-claw setup (seals, bearings, steering "ball" etc.) is different enough from the birfield setup that you won't be able to use the ball and claw housing, and simply swap the knuckles.
I think the only option is putting a 1976+ FJ40 (disc brake) axle under the truck, housing and all. Ideally, you want the even later axle (I believe 79 or 80+) to take advantage of the fine spline, large pattern birfields. Also keep in mind if you go 79+ you will be inheriting a 3.7:1 differential, so you'll need a matching rear gear set as well.
If I recall, I believe the only compatible mini truck knuckles with an FJ40 are the pre-IFS mini truck knuckles (79-85, I think). Not sure if you could toss the whole mini truck axle underneath...probably an issue with width or differential location.
Long story short, I think you need to replace the entire axle, housing and all, to modernize the brakes/knuckles...I might be wrong though, I'll let someone else chime in who has more knowledge of the older axles.
The diff housings (third members) interchange, so you'll need to find a later model fine spline diff. You'll need the fine spline inner axles to match, then it's just a matter of locating the appropriate knuckles and related disk brake components.
Either FJ60 or mini-truck disk brake assemblies will work. If you go for the mini-truck parts you'll need to look for a '79 - '84 solid front axle truck, NOT IFS.
The swap requires a little clearance work inside the ball to fit the larger birfs. You'll also want to upgrade your brake system with a brake booster and tandem brake master cylinder. You'll also need to split the front and rear systems and provide a proportioning valve for the rear brakes.
Having said all that, yes, a straight across swap with a later model FJ40 disk brake front axle is easier if you can find one.
He said ball and claw. For those of us that have done this swap I seem to possibly remember ONE swap that utilized the old housing. Yours has a bushing where an oil seal goes inside the axle housing. And smaller studs on the diff. The bushing inside the axle housing is your nemesis. Somewhere within the mud search system might possibly be a pn for a seal that might work. And possibly you might be able to just swap the spider gears inside the diff for fine spline. Thus possibly utilitizing your diff. Those are your biggest hurdles. Most of us get a newer housing and go from there. And like it was said IFS will not work only solid axle assemblies. There seems to be a kit from MAF or (cough) JTO (whom I do not at all recommend) that puts a different brake system swap for front drums that might be easier for you. With a newer diff you might need a different driveshaft flange as well depending on year or drill out your shaft for bigger driveshaft bolts. The earlier shafts dont have as much meat left on the bone tho.
Then the master cylinder and associated plumbing. Yours runs different sized fittings 9mm vs 10 if I recall correctly. And one piston in master non boosted instead of dual setup. Marks off road has an adapter to run boosted or non boosted on your firewall as do other companies.
If your mechanically inclined and do your research and understand how brake systems work or purchase some sort of all inclusive kit you'll be safe. By safe I mean stopping the truck safe.
This is why I personally never buy into a pre 69 FJ40. The best way to get everything to work well is to bite the bullet and do it right. Which means copying what Toyota did with the later trucks. First step is to cut out the welded in pedal assembly and replace with a later bolt in style. This moves the brake booster and clutch slave out to clear the intake/carb . Not a critical issue for the "F" motor but if you ever want to go to a 2F it will be. You'll be doing some sheet metal work like angling the support rib on the engine bay firewall and patching the old brake and clutch holes. The new "bolt in" pedal bucket self aligns with the
bolt holes for the steering column support so cutting the new master cylinder positions is self explanatory.
Now you can use a factory booster, brake master, clutch master, etc. If you retain your stock rear brakes you'll have to 10 mm ends on the hard line at the master. When you go to Toyota discs everything will be 10 mm on the front brake circuit. If you go to rear discs use an FJ80 master for "93
and later
I'm putting a LS1 motor in with a 4l80e tranny so I have the overdrive. I'm redoing the whole firewall and pedal area like you said also, sound like I need a new axle to do what I need to do.
Where I live people want alot for a front axle out of mini truck and a little more for the cruiser stuff but have found fj60 axles for cheaper but they are 3" wider from what I'm told so I've thought about doing that as well and outboard my springs on the front. I like the 64 because you don't see them much anymore but mine is not worth a true restore.
I did the swap on my 69. I was going to do my 72 but got a deal on swapping for a completed disc brake with lockers. You can look up my post when I did it. It is a full days job that took me ablut 1 week.
I have a axel from a fj60 available if your interested. I am in napa ca.
Ill check it out on your thread, don't know what shipping would be on that axle I've looked at the scout 44 axles also but people say its a downgrade from toyota but easier to work on so its really confusing to me, and having advise is best when new to the 40s
Consensus is that 44s are a downgrade. 60 axles are likely the most affordable, and shouldn't be too hard to find. I'd also consider a Toyota motor as well, a 3fe or a 3b... Diesels aren't that far away to the birth for you.
Ill check it out on your thread, don't know what shipping would be on that axle I've looked at the scout 44 axles also but people say its a downgrade from toyota but easier to work on so its really confusing to me, and having advise is best when new to the 40s
If you use a Dana 44 that has an offset rear to match the LC T-case then you're going to have to go way back to when they used Dana 18 cases. These were typically small tube, 1.175 10 spline axle shafts. The 69 and later Cruiser axle axles are 30 spline 1.31 " . Later Dana 44 also used that same axle dimension however scouts had switched to the Dane 20's and 300's by that time so the rear axles would be centered. Only the Dane 44 HD would be comparable in strength in my opinion. They'd be a large tube (3ish") and found on full size trucks and newer Rubicon edition Jeeps. As far as I'm concerned the LC, Ford 9" and others with the drop out third are the easiest to work on. The Dana style are far more difficult.
Their axle seals are inside the axle tube at the diff. Changing them involves complete disassembly, removing the ring and pinion from the housing where the cruiser's seal are fight out at the end, easily accessible. Shimming the ring and pinion on a Dana is done in the carrier and may involve numerous assemblies and disassemblies. The LC can be done entirely on the bench. You can even preassemble one for the trail
Ok I didn't know that on the d44, does the 60 series have the same support as the mini truck and lc then. What would be a good year? I've heard of them with lockers from the factory and I'm leaning that way for a wider stance and have been told its not real noticeable unless they know Cruisers.
