Front axle identification for converted 69 FJ40 (2 Viewers)

[lpnsocal]

I recently purchased a 69 FJ40 and found this great site while learning about my new project. .It has a 350 w a 700R4 auto, 2.5" Ol Man Emu lift, power steering, power disc brakes all around and a number of unfinished fixes, one of which I'll discuss here.

First thing I had to do was fix a leak in the interior fuel tank but that quickly made realize I need to prioritize the repairs/mods. I am giddy to get her reliable enough for a good adventure..., but I'm gonna start with some safety issues first.
The front axle seals are leaking profusely and need to identify the axle to purchase correct complete rebuild kit. Most research has turned up best to identify it by the stud distances on the steering arm. Unless of course I missed an easier way, which is frequently my issue. Can anyone identify it from these pics? Looks to be about 2 in from front stud to back stud.

I may be opting to buy the special(very pricey) tool that helps center the steering knuckle, so if anyone has a line on an "affordable" one, I'd appreciate that too!
Thanks in Advance,
LP

 

[1969FJ]

I have a 1969 and it has a drum brake axle. Your axle is converted disc which I believe started in 1976 and above.

 

[lpnsocal]

I have a 1969 and it has a drum brake axle. Your axle is converted disc which I believe started in 1976 and above.

Thanks.
I knew that it was a a conversion, but I'm so new to this vehicle i wasn't sure what it takes to go from drums to disc and if the whole axle has to be changed out or ? And that still leaves me with getting the correct rebuild kit for.....whatever I have.

 

[pb4ugo]

Looks like you found a nice 40. You're using the wrong side of the ruler try mm.
At the top of the 40 section, click faqs, scroll down to frt ends and read the 1st thread.

 

[lpnsocal]

Looks like you found a nice 40. You're using the wrong side of the ruler try mm.
At the top of the 40 section, click faqs, scroll down to frt ends and read the 1st thread.

Ha...,,I saw the inch side after the photo and said the same thing! But .., following your advice and looking under "Poser's" Steering knuckles 101, I think I have some measurements to help narrow it down to which axle I may have(fingers crossed. ) Tomorrow measurements in metric!

 

[DangerNoodle]

That is an aftermarket GM disk brake conversion. Most of the ones I have seen are somewhat sketchy. I would reccomend going either 76 or later FJ40 or minitruck disk brake conversion. I would highly recommend a SUMO rebuild kit, Cruiser outfitters is a great option for that. 4x/5x Series Knuckle Rebuild Kit - Fits 1958-9/1975 4x/5x Series Drum Axle - https://cruiserteq.com/4x-5x-series-knuckle-rebuild-kit-fits-1958-9-1975-4x-5x-series-drum-axle/ or 4x/5x/6x/7x Series Knuckle Rebuild Kit - Fits 9/1975-12/89 4x/5x/6x/7x Series & 1979-85 PU/4RNR Disc Axle - https://cruiserteq.com/4x-5x-6x-7x-series-knuckle-rebuild-kit-fits-9-1975-12-89-4x-5x-6x-7x-series-1979-85-pu-4rnr-disc-axle/.

Easiest way to tell is to pop a hub off and check if it is a coarse spline axle or later fine spline. Given that it is a non-oem disk conversion, I would be betting on coarse spline.

I personally wouldn't bother with the recentering tool. Basically every single axle that I have seen has a thick and thin shim on top, and a single thick shim on the bottom, unless it has be mucked with before. As long as you keep those the same, it won't matter.

OEM disk brake conversions are really easy, you just swap everything besides the third and axle housing over. You can still get rotors, pads, and calipers from most parts houses, or toyota for some certain fj40 rotors. I can do one, including teardown and cleaning of both axles, in under 8 hours usually, unless they require real paint, or are so disgustingly packed with old oil and grease that takes forever to come off.

 

[DangerNoodle]

Also, my guess is you have the 'small pattern small hole' steering arms, which is earlier 40, and some disk brake 40. There is also small pattern big hole (i.e fj60 taper), which was some later 40 and much less common, and big pattern big hole, or fj60 steering arms. I've done conversions with all three, you just need to watch out which TRE's you use.

 

[B y r o n]

You say the front axle seals are leaking profusely but all I see is normal seepage that hasn't been washed off in some time. Take a pressure washer to the undercarriage, ensure the knuckles are filled and see what transpires. Fix the gas tank leak and enjoy your new ride.

 

[lpnsocal]

Thanks for all the replies! I guess baby steps are gonna have me running in no time! I did remember the Seller stating that the disc pad replacement were GM/corvette.(Type of disc brake conv. still taken with a grain of salt considering his short term of ownership!) Hopefully, this conversion can suffice until I shorten the list a bit.

I did go the path of least resistance and measures studs and distances. It looks like 11mm studs(10.82 threads) and 46mm to centers(using some math I remembered.)

So.........., early drum axle knuckle rebuild kit needed?

Speaking of needed...

You say the front axle seals are leaking profusely but all I see is normal seepage that hasn't been washed off in some time. Take a pressure washer to the undercarriage, ensure the knuckles are filled and see what transpires. Fix the gas tank leak and enjoy your new ride.

Submitted for your approval, this from 6-8 wks parked. Excessive?, rebuild?

BTW, fuel tank repaired. Aux fuel tank to be pulled and cleaned later. This repair adventure started with int tank repair and evolved into, E brake installation, pas door hinge adjustment, knuckle rebuild and maybe heater shut off valve install.

I appreciate you guys checking the deep end as I dive in!

 

[B y r o n]

With the clearer pictures I vote for time to rebuild.

 

[lpnsocal]

Also, my guess is you have the 'small pattern small hole' steering arms, which is earlier 40, and some disk brake 40. There is also small pattern big hole (i.e fj60 taper), which was some later 40 and much less common, and big pattern big hole, or fj60 steering arms. I've done conversions with all three, you just need to watch out which TRE's you use.

I'm sure this is very relevant to what I'm trying to discern, and maybe more so due to my saginaw power steering conversion, which is on the list to address because it's a quick ratio and is part of my twitchy steering I need to address.

I'm guessing your direction to this link is the product I need based on my measurements? 4x/5x Series Knuckle Rebuild Kit - Fits 1958-9/1975 4x/5x Series Drum Axle - https://cruiserteq.com/4x-5x-series-knuckle-rebuild-kit-fits-1958-9-1975-4x-5x-series-drum-axle/

I personally wouldn't bother with the recentering tool. Basically every single axle that I have seen has a thick and thin shim on top, and a single thick shim on the bottom, unless it has be mucked with before. As long as you keep those the same, it won't matter

I'm not sure I'm qualified to know if it's been mucked with, leading me me to error on the side of caution/expensive tool.


Lastly, What are "TRE's" and Is there something else I need to address while I'm working in this vicinity?

thanks!

 

[bikersmurf]

Tie Rod Ends.

Hopefully someone can loan you the tool.

I’d guess that your drum knuckles haven’t been mixed and matched. For now I’d just throw some new seals and gaskets and put the shims back in where they were. If the preload is about 5lbs you’re good to go.

I’d swap in Toyota disc knuckles and brakes in the near future… so much better than GM callipers on the front.

 

[pb4ugo]

Check bushings, tre's, tighten the u bolts, then Check you caster angle. Twitchy is usually related to negative caster. Has the 40 been lifted, extended shackles or any other suspension mods? How about some over all pics so we can see the whole setup.

 

[lpnsocal]

Check bushings, tre's, tighten the u bolts, then Check you caster angle. Twitchy is usually related to negative caster. Has the 40 been lifted, extended shackles or any other suspension mods? How about some over all pics so we can see the whole setup.

Thanks for chiming in! It does have a 2.5" O. M. E . lift/shocks that's fairly new, steering feels tight. When I say "twitchy" I mean sensitive as all get out. Tracks straight with no pull. No shimmy or speed wobble, just literally have to keep my hand/arm resting on lap or ..? to limit unintended movement.

I think it best I save this issue for a different thread, as I did buy a replacement Saginaw(regular ratio) that I'm going to rebuild and simultaneously check all steering arm lengths, angles, etc before I install. At that time I'm certain I'll be whining for help(in a different thread.)

 

[bikersmurf]

Thanks for chiming in! It does have a 2.5" O. M. E . lift/shocks that's fairly new, steering feels tight. When I say "twitchy" I mean sensitive as all get out. Tracks straight with no pull. No shimmy or speed wobble, just literally have to keep my hand/arm resting on lap or ..? to limit unintended movement.

I think it best I save this issue for a different thread, as I did buy a replacement Saginaw(regular ratio) that I'm going to rebuild and simultaneously check all steering arm lengths, angles, etc before I install. At that time I'm certain I'll be whining for help(in a different thread.)

I think you’re on the right track. 2.5-3 turn lock to lock Saginaw boxes can have undesirable characteristics. They are often described as twitchy… if you sneeze you may find yourself in a different lane, and if you’re not on your toes you’ll be very startled. I’ve never driven one… and some owners love them.., but it’s certainly not for everyone. I’ve always read you should have 3-5* castor rather than the original 1*.

I’ve got a Scout II Saginaw box. It takes 4.25 turns to go lock to lock. I think this is slightly slower than Toyota’s original manual box. I absolutely love it. Tracks straight, not at all twitchy, and it feels like it came factory original. By that I mean I can easily turn with one finger (or the smooth palm on smooth steering wheel) lock to lock on dry pavement with 33x10.50 AT tires at 25 psi. I’ll emphasize it doesn’t feel light and floaty… it feels completely natural, and I don’t for a moment realize it’s “over assisted” power steering. It feels great and I don’t give it a second thought (even after driving this same 40 for 30 years with Armstrong steering.

 

[pjohnson]

When you say you bought a 'regular' saginaw box, I think of the typical 2.5 to 3 turn boxes. The 4.25 turn boxes are not 'regular'.

I strongly suggest getting your caster set correctly first as mentioned by @bikersmurf and then see how it rides.