Interchangeability of knuckles FJ40 to FJ60 (1 Viewer)

[ASI H8]

Will the FJ60 knuckles fit the 78, FJ40 axle?

What I have is a 1978 FJ40 front axle. I’m the process of rebuilding it to go under my Samurai. When I install the axle it will be sprung over and rolling 38”. Being sprung over does not require high steer though it is highly recommended.

I’ve looked around for high steer arms for the narrow bolt pattern but having trouble finding any. There is a guy out west that will bend arms to a high steer configuration but it takes about a month, sometimes two to get them back. That route is out.

I know the FJ60 knuckles have the larger bolt pattern and there is a local guy or two that might have a set taking up space. I also know the availability of high steer arms are greater for the larger bolt pattern found on the FJ60 knuckles.

So if the 40/60 knuckles interchange I see two routes:

• Find quality high steer arms for the stock narrow bolt pattern FJ40 knuckle
• Swap to 60 knuckles and again find quality high steer arms

Sourcing and Suggestions appreciated.

 

[tornadoalleycruiser]

Either option will work 60 and mini knuckles are the same and I have the sst to set shim stacks. Call with questions. I have done tons of this swap. Ill look for small knuckle options as well if u want

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[ASI H8]

Either option will work 60 and mini knuckles are the same and I have the sst to set shim stacks. Call with questions. I have done tons of this swap. Ill look for small knuckle options as well if u want

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I'll take you up on the offer to barrow the sst to set the shims. I figure I'll be needing it within the next month or so.

That is great to know. I have the original knuckles and arms but the arms are stock. IIRC High steer arms for the original knuckles cost around $250 and up. This doesn't include links/ends between steering box and axle. I know of a set of FJ60 knuckles and arms local to me. I don't know how attached the owner is to them and if owner would be willing to give or sell.

I guess it comes down to three factors, Time, Quality and Cost.

I don't have a lot of time. That can be made up by spending more, quickly. A quick purchase to get the part needed could be less than "quality". Less quality means I'll spend more time correcting later.

So I guess the next question is, what is the best balance between Time, Quality and Cost?

I assume that a wider bolt pattern found on 1979 FJ40, Mini Trucks and FJ60's are more desirable/durable than those on the 1978 and earlier FJ40. I know as far as high steering arms, there is a larger market.

 

[tornadoalleycruiser]

Go with the bigger knuckle pattern if possible for parts avail amonst friends. for a driver, small is fine. for hysteer.. 2 options.. 4x4 labs or others. almost all the others are the same. you can use 80 series TRE's and weld inserts to make your own steering relay rod and tie rod if you wanna go cost effective. and given the custom application you will probably need to.. i did..
when doing any knuckle i do now recommend the following.. bypass the backing plate, make either a delete plate or buy a delete plate. vented rotors, Marlin inner seals, Koyo knuckle bearings (trust my experience on this.. Timken are a totally different pn, taper etc and don't set the shim stack as well)
I have the PN for the new flex hose from axle to caliper. I'd upgrade to v6 calipers as well.

the older knuckles have value just not near as much.. and you probably need the newer birfs and lockouts or use either 76-78 or 79-90 as a unit.. they are different lengths. you can use newer birfs with older hubs but not older birfs with newer hubs.

 

[tornadoalleycruiser]

Considering your in odesssa. really.. best to just come by and drink free beer and learn. bring an older knuckle assembly including birfs and hubs and i can show you all the issues.

 

[ASI H8]

Where to start?

Go with the bigger knuckle pattern if possible for parts avail amonst friends. for a driver, small is fine. for hysteer.. 2 options.. 4x4 labs or others. almost all the others are the same. you can use 80 series TRE's and weld inserts to make your own steering relay rod and tie rod if you wanna go cost effective. and given the custom application you will probably need to.. i did..

OK Yoda. SLOW DOWN. Let me see if I got this right here. Go with 60's, 4x4 Lab high steer arms, 80 series TRE's, weld inserts into relay/tie rod due to custom application.

when doing any knuckle i do now recommend the following.. bypass the backing plate, make either a delete plate or buy a delete plate.

Backing plate? Don't know if I still have the old plates or not? I'll have to look in my box of stuff.

vented rotors,

Current rotors are in great shape. Maybe later (time and $$)

Marlin inner seals

Got'em

Koyo knuckle bearings (trust my experience on this.. Timken are a totally different pn, taper etc and don't set the shim stack as well)

I think I got'em. Again I'll have to check the axle box. I think I bought the upgraded kit from Marlin. Let me check.

I have the PN for the new flex hose from axle to caliper.

Cool. That seems like a no brainer, easy on time and $$. Send it!.

I'd upgrade to v6 calipers as well.

From what year and make of rig? Should I go NIB or Pick and Pull?

the older knuckles have value just not near as much.. and you probably need the newer birfs

There is/was a debate on what birfs I have. I think they could be TG birfs and outer axle shafts. I'll post picts when I get back to the house.

and lockouts

I'm pretty sure I can get a hold of a complete set of 60 knuckles out to lockout caps but the question comes back to birfs and outter axle shaft length, correct?

or use either 76-78 or 79-90 as a unit.. they are different lengths. you can use newer birfs with older hubs but not older birfs with newer hubs.

Again I'll post picts of the birfs I have.

Considering your in odesssa. really.. best to just come by and drink free beer and learn. bring an older knuckle assembly including birfs and hubs and i can show you all the issues.

Yeah, He!! Yeah. I'll grab all the parts, what not and swing by. I'm sorry. Did you say FREE beer? Of course I'll be there for the education.

 

[ASI H8]

Birfs

So the complete stamping reads
BIRFIELD-NTN IGO AC TG
They do have a threaded hole on the end of the outer axle shaft and the inside of the axle housing has been clearance to fit something larger than intended
So you tell me. Newer or BS?

 

[tornadoalleycruiser]

Bring it by. Tomorrow will work as will weekend. I can explain In person with show and tell..

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[ASI H8]

Thank you, Tornado Alley Cruiser for your time and that care package.

What I learned.
1. Axles are bone stock.
2. I'm in deep but not over my head, and
3. A few of you that brew beer make a dam fine IPA.

What I need to do:
1. Get perches placed on the front axle. This opens Pandora's box of other stuff I'll be able to work. Steering/linkage, brakes, axle assembly
2. Remove front clip, fenders and wheel wells. This is going to be a challenge. I’d like to be able to sell or keep it for a project later.
3. Mount shock hoops. I’ll need help on this as I don’t have or know how to weld
4. Mount steering box. Figure out linkage to the arms.
5. Drive shafts. How long do those take to build?

 

[tornadoalleycruiser]

Welding. Well. Depends on where its at.
Driveshafts. 24 hours depending on where ordered from.. tom woods advertises in trails. Can build custom length and ends so thats an option.

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[tornadoalleycruiser]

What I would do. Build the knuckles. Arms and linkage can easily be done after that. Ubolt the axle on with the perches to set pinion and caster. With weight on it. Then weld perches and shock mounts on after axle is placed.

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[ASI H8]

Welding. Well. Depends on where its at.

It will have to be at my place. Rig isn’tvery mobile right now.

Driveshafts. 24 hours depending on whereordered from.. tom woods advertises in trails. Can build custom length and endsso thats an option.

Yeah I’ve seen Tom Wood’s drive shafts. I went to his site and pulled down all theinformation he needs to build one. There are Samurai T-Case flanges to Toyota drive shaft adapters. I think I’m going to head down that road. Will all the drive shafts laying around I thing I can find something that works.

What I would do. Build the knuckles.

OK. Start at knuckles. Thanks again for the care package. I still need to source a backing plate. I found one that came off the axle I’m working.

Arms and linkage can easily be done afterthat.

Arms and linkage are on their way. 4x4 Labs (Luke?) got back in touch with me last night. Come to find out the 40 axles under a Samurai isn’t that uncommon. He has done enough in the shop that he has the measurements on file. He suggested the GM ends (as you said he would). I’m going 80 series ends because, well, I have one. I didn’t getan ETA on those. And with Mother Natureall pi$$ed, ………..

Ubolt the axle on with the perches to setpinion and caster. With weight on it. Then weld perches and shock mounts onafter axle is placed.

I did pick up some U-bolts, plates and perches. If you remember the perches that were on the axle tube were already set up for sprung over and the welds looked like boogerfest. I cut those off. I still need to grind down the boogers and prep the area for perches.

I ordered the rear suspension Monday. It should be in Thursday ( ? pending Mother Nature).

Again thanks for the care package. Ton of information.

 

[tornadoalleycruiser]

Backing plate delete? Cut your old one down keep the center ring. If u need a spare holler. I can cut u a couple if needed and give to jobe. The center is needed for proper spacing of the spindle. Just place the new delete where the complete one went per pic in yellow pamphlet

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[ASI H8]

It has been a bit since I posted any progress. Well progress is happening, though not as quick as I'd hoped. I'm going to be hard pressed to get things the way I want them prior to BMR. I did get the knuckles on, front axle under the springs. I plan to have it rolling tonight. Later this week I'll be moving it to a better equipped shop to finish it out.

 

[ASI H8]

I took a few pictures of the rig when I got it rolling. I'll get them posted up when I get back to the house (late Friday night). There is a large difference between a 3.5" lift on 30" tires compaired to a 6" lift sitting on 38.5" tires. I might have to scale the tire size back to 35's.
Foreseeable issues: tire rub on springs and tub, placement of IFS steering box, placement and pully for PS pump, and, as always, Murphy.