Build 1970 FatherSonJ40 project

[Kmehr]

Well after some head scratching, measuring etc. in planning my steering linkage setup, I have discovered my tie rod is bent. So the potential domino effect is in place. I have the small bolt pattern steering arms on my knuckles, so aftermarket steering options are pretty limited. I also have disc brakes of unknown origin up front. A full high steer setup would be really nice, and the price on that alone is stomach able, but when you throw in the need for new knuckles too it gets steep fast. Decisions....

 

[pb4ugo]

Sounds like you want to go down a rabbit hole. It's not that small pattern knuckles are weak, it's that large patterns are stronger. I ran sbc's and a BBC with power steering and an open small pattern frt end for yrs. I started breaking birfields when I put a lockrite in the frt. I ran aggressive 33" tires. This was way b4 longfields were available. You can build what you have now and slowly collect parts if you want large patterns. You can upgrade your birfs to alloys with what you have now. I recently adapted scout steering on my street 40. While I was building the steering an FJ60 frt end fell into my lap. I will b drive it for a while and at some point I will rebuild my knuckles with the fj60 knuckles. In the future it will get alloys and an arb.

 

[Kmehr]

I wouldn’t say I necessary WANT to go down that rabbit hole…it would just be nice to have all the heavy duty stuff and all FJ80 TREs. What I think I’ll do is just get the Bud Built tie rod, and then make my own drag link with an insert in one end for an FJ80 TRE to my FJ80 box and the other end a standard FJ40.

I’m definitely a fire road and explore type of off-roader, though I want to take this to Moab at some point. Even then, I’m pretty easy on my stuff. Mostly this will be a gently used rig so the big arm upgrade will way overkill for me.

 

[Kmehr]

Well I think I found a set of FJ60 knuckles for a reasonable price, so I'm just going to go that route. Wouldn't hurt to rebuild/reseal everything up there of unknown origin. I keep justifying these upgrades with "my family is going to ride in it" so its for safety right?!

I think I'm just about there from a parts standpoint for the power steering and hydro boost brakes standpoint. Have FJ60 knuckles and rebuilt kits on the way, High steer kit from Trail gear, Sweeting hydro boost/master/lines/prop valve, F250 shock towers, Saginaw PS pump/pulley/mount, and TPI column bearing. The only big piece left is the steering shaft, but I need to get things a little more disassembled to be able to measure up for that. Now just to get the time to work on it and weather to cooperate!

Oh and had to order a new pressure switch for my old air compressor. Really hoping I can get that going again so I can use my plasma cutter to cut the frame plates.

 

[Kmehr]

Doing as much reading and research as the parts trickle in, I think I may have made a mistake on the high steer kit- I *think* I have 4in lift springs, based on what the previous owner told me, but he also wasn't sure if it was 2.5in or 4. I can't find any ID info on the springs. I went with the Trail Gear HS kit as I thought I read where it worked with 3-4in SUA lifts. Can anyone confirm this? I don't think I'm throwing away money moving to the FJ60 knuckles and doing the rebuild, but maybe I need to revisit my steering arms choice. I don't really see a way to do the FJ80 box without at least a custom draglink, and I'm comfortable dabbing that myself using the HS kit, but sounds like arms a different story and that's not something I can make myself. Most sites have limited stock on stuff, but happy to take suggestions. I definitely don't want to go SOA though.

 

[Kmehr]

Just spoke with Trail Gear and they said you only need about a 3in lift on a SUA to run their High Steer kit, so that is good news. My backup plan, and maybe other who read this later, was to pickup SOR HD steering arms (they have them in stock apparently), then Man-A-Fre sells a complete "super heavy duty" Fj60 steering linkage setup that looks like it would work for anyone doing the FJ60/FJ80 steering conversion. I'm about done with my basement remodel, so hoping to get some real progress done here in December.

 

[Kmehr]

Some not so exciting progress, was able to get my old compressor fixed so my plasma cutter will be up and running. Wrapped up my last big project of the year at work this week, so should have some serious wrenching time next week. Have just about all of my parts in with the exception of steering shaft, PS pump/mount, and hydro booster. Up first is going to be the knuckle rebuild so I can have a better idea of geometry before I make any permanent changes.

 

[Kmehr]

Got a little done today. Have everything torn down and pulled off. Rough cut some frame plates for the power steering mount, but still haven’t decided exactly how I want to mount it. I had 3/8th plate laying around and some 1/4, so I think I could stack that and space enough from the frame that I wouldn’t have to cut into the radiator support at all, but then I think I’ll have some clearance issues with the Ford shock tower I’m going to use. Or I could just move that support over about a half inch, flip side there though is I’d have to rework the fan shroud. Decisions decisions.

 

[Kmehr]

looking around I see that many use the plastic 6 blade fan as an upgrade and that it is also a smaller diameter than the metal 4 blade. I like this idea. Can anyone tell me the diameter difference between the metal and the 6 blade plastic? That alone might solve the fan shroud placement issue if I move the radiator support over some.

 

[Roastchestnuts]

Got a little done today. Have everything torn down and pulled off. Rough cut some frame plates for the power steering mount, but still haven’t decided exactly how I want to mount it. I had 3/8th plate laying around and some 1/4, so I think I could stack that and space enough from the frame that I wouldn’t have to cut into the radiator support at all, but then I think I’ll have some clearance issues with the Ford shock tower I’m going to use. Or I could just move that support over about a half inch, flip side there though is I’d have to rework the fan shroud. Decisions decisions.
View attachment 3186936View attachment 3186937

Ill have to look at mine but I have some sort of power steering upgrade. Looks to be a toyota box. I think mine is just mounted right to the frame some how.

 

[Kmehr]

So a 3/8plate stacked with a 1/4in plate is the perfect space to move the steering box from the frame so I don’t have to mess with the radiator support at all. I also think with the F250 ford shock tower, the unjoint on the steering gear will probably clear as is. Might have to space the shock tower out 1/4in too, but that would be a piece of cake. Here are some photos with that plate stack and the shock tower clamped in place, for an idea of the spacing.

 

[pb4ugo]

Looking at your setup you might want to look at the position of the frt of your box and how it relates to your frt bib and how the frt of the fender attaches to it.
It looks like you will be cutting into mounting flanges of the bib & fender. At some point you'll have to clearance for the box by cutting the fender and possibly the bib or clearance the fender like I did. Also put the pitman arm on the box and make sure when the drag link and tre is installed it doesn't interfere with the frame rail. Something else to look at is the relationship between where the tre on the drag link/pitman arm and the tie rod below. Too much angle between the drag and tie rod can cause bumpsteer. I know this is apples and oranges, but my 1st scout setup I used the Ford tower. I had to scab out my box like your considering and it works fine. I just I didn't care for the look of the tower. On my 2nd scout box, I was determined to use the stk shock mount with some alteration and moved it back and bolted it on the frame and reversed the shock pin. I didn't scab the frame on the outside because the PO moved the rad support over to center the sbc fan to the stk shroud. It looks like if you move the stk shock mount back you may be able to use the stk tower with minimal alteration to it. I put the frt shock mounts holes into the rear shock mount bolt holes in the frame and drilled the frame for the back holes.

 

[Kmehr]

Looking at your setup you might want to look at the position of the frt of your box and how it relates to your frt bib and how the frt of the fender attaches to it.
It looks like you will be cutting into mounting flanges of the bib & fender. At some point you'll have to clearance for the box by cutting the fender and possibly the bib or clearance the fender like I did. Also put the pitman arm on the box and make sure when the drag link and tre is installed it doesn't interfere with the frame rail. Something else to look at is the relationship between where the tre on the drag link/pitman arm and the tie rod below. Too much angle between the drag and tie rod can cause bumpsteer. I know this is apples and oranges, but my 1st scout setup I used the Ford tower. I had to scab out my box like your considering and it works fine. I just I didn't care for the look of the tower. On my 2nd scout box, I was determined to use the stk shock mount with some alteration and moved it back and bolted it on the frame and reversed the shock pin. I didn't scab the frame on the outside because the PO moved the rad support over to center the sbc fan to the stk shroud. It looks like if you move the stk shock mount back you may be able to use the stk tower with minimal alteration to it. I put the frt shock mounts holes into the rear shock mount bolt holes in the frame and drilled the frame for the back holes.

all good info! That position isn't exactly where the box will end up, ive got that white line drawn on the frame where the bib hits, so the front to back position of the box isn't final yet, I was mostly going for the spacing of the frame/box/radiator support at this point. I just ordered my steering shaft parts this morning, so don't have all of that yet to use for mock up.

I'm not 100% on the Ford shock tower, but it seems like likely the easiest option right now. I think either way, mounting the box, steering shaft and steering linkage first makes the most sense to me, then I can work around that for the shock mount. I like the idea of scooting the stock mount forward and then flipping the shock pin. Will have to play with that as I move along.

I also haven't ordered a Pittman arm yet, but I probably should go ahead and do that so I can make sure that angle looks ok. I'm still a bit nervous about the high steer setup not clearing what I have. One tech from Trail gear said that it should work with 3in SUA and up, and another emailed me and said they've never tested it on a SUA setup. I unfortunately think I'm going to have to just go for the install and see if it works.

 

[pb4ugo]

Yeah, get all your parts set up and cycle thru the steering b4 welding up . I'm just throwing out where possible issues might show up. I posted earlier in you thread on how I altered my fender.

 

[Kmehr]

Yeah, get all your parts set up and cycle thru the steering b4 welding up . I'm just throwing out where possible issues might show up. I posted earlier in you thread on how I altered my fender.

I actually have that picture saved as I want to do the same with my fender once I'm finished with everything! It's really nice work. I'm definitely planning on a ton of tack welding, grinding and shifting as I move along haha

 

[CruisinGA]

@Kmehr i did FJ60 with hydro assist in 2009 before it was popular. I used 1 ton tie rod ends and made my own tie rod and drag links with .25” wall dom. Happy to provide guidance based on my experience.

Also on brakes- you do not need hydro boost for good brakes.
I run very heavy 38” Michelins for my street tires (heavier than 38.5 swampers or Irocks that I ran previously).
I could not stop them until I upgraded to 4Runner front calipers, a tandem mini truck brake booster and FJ80 master with disk brakes in the back. Now it has pedal feel and stopping that anyone including my short, small wife can drive.
The booster and master cylinder are available from city racer.

 

[CruisinGA]

Started the tear down for the power steering. The FJ80 box is huge! Is definitely going to be a huge improvement. The radiator and grill definitely need to come off. Looking at it, the shock tower is the biggest source of interference and basically just flipping the support around to be to the rear of the truck seems to be the best way to get it out of the way.

I notched the back of the shock tower and was able to keep it in the stock location.

If I had not been able to do that I likely would have switched to the popular Ford shock towers.

 

[Kmehr]

@Kmehr i did FJ60 with hydro assist in 2009 before it was popular. I used 1 ton tie rod ends and made my own tie rod and drag links with .25” wall dom. Happy to provide guidance based on my experience.

Also on brakes- you do not need hydro boost for good brakes.
I run very heavy 38” Michelins for my street tires (heavier than 38.5 swampers or Irocks that I ran previously).
I could not stop them until I upgraded to 4Runner front calipers, a tandem mini truck brake booster and FJ80 master with disk brakes in the back. Now it has pedal feel and stopping that anyone including my short, small wife can drive.
The booster and master cylinder are available from city racer.

Definitely am interested in an alternative to replacing my knuckles and arms, even though I bought them already. Would love to hear about your tie rod setup.

I’m sure I could have replaced and tuned the current brakes, but I did hydro boost on my old dodge truck and it was the best mod I did, plus I’ve already ordered it…

 

[CruisinGA]

Sorry I wasn't clear. I also upgraded knuckles and arms because I was pretty hardcore rock crawling with lockers front and rear and 38"s on beadlocks. I needed the strength of the larger pattern on the steering arm and the ability to run the strongest birfield/longfield I could get which both required swapping the knuckles.
Using the 1-ton tie rod ends took care of adapting from 80 series pitman arm to 40 series knuckle, and was not expensive and is strong just meant I had to ream out the pitman arm and steering arms for the taper of the TRE's.
If you are a fire road guy, and since you already have disk brakes on the front this may be all unnecessary.

 

[Kmehr]

Sorry I wasn't clear. I also upgraded knuckles and arms because I was pretty hardcore rock crawling with lockers front and rear and 38"s on beadlocks. I needed the strength of the larger pattern on the steering arm and the ability to run the strongest birfield/longfield I could get which both required swapping the knuckles.
Using the 1-ton tie rod ends took care of adapting from 80 series pitman arm to 40 series knuckle, and was not expensive and is strong just meant I had to ream out the pitman arm and steering arms for the taper of the TRE's.
If you are a fire road guy, and since you already have disk brakes on the front this may be all unnecessary.

So you were able to ream the FJ40 steering arms to 80 series ends? I haven't found much info on that other than a few folks saying they didn't think there was enough meat on the 40 knuckle arms? Frankly I would love if that is a realistic option vs. the pretty large project of completely rebuilding and replacing my knuckles. I'm definitely not a hard core rock crawler. My use will be fire roads with my family on a nice day with the top off, and hunting. Maybe a trip to Moab every 5 years or so with buddies, but I would trailer out and back in case I broke something. Planning on flat towing it behind my cummins for camping trips.