- Thread starter
- #21
Not cheaper or stronger that I know of but I like that idea of using a many land crusier parts as possible for this build.
My (mostly) Toyota Hybrid Front Axle Build for FJ40
- Thread starter Chris Wilcox
- Start date
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This has been discussed over and over again. A couple quick points:
- A stock kingpin D60 front end is about as strong as a built Land Cruiser front end, assuming you're talking the 9.5" diff 'yota axles
- Kingpin D60s go for anywhere between $900 and $1200 by themselves, but you can buy a whole truck and part it out to get the D60, then it can be free (that's what I did, and mine was free)
- It costs at least $1000 to build a Land Cruiser front axle, with 6 shooters / hellfire knuckles, RCV inners, etc.
Using the LC axle is generally done to keep a build Toyota-centric, which I love to see. I love Moonshine, but she's not much of a "Toyota" anymore. Part of me wants to buy another 60 to play with and keep it all Toyota.
Bump, very interesting. I'm picking up the rest of my parts to do this same build. It will be basically the same as yours but without the e locker. Is there a way to use the stock fj60 axle shafts with the 80 birfields, such as getting rcv 80 series birfs? I believe I read they are 24 spline and the 80 splines are 30/27?
60 shafts will not be compatible with 80 birfs. 80 birfs are 24 spline at the star, 60 shafts are 27.
If you can find 30 spline 80 birfs you could run 60 width 30 spline inners, I am not sure where things stand with super 30 80 series stuff.
Just build an 80 width housing if you don't want to mess with custom inners.
awesome thread great tech. Dana 60s arent for everyone, contrary to popular beliefs. 
- Thread starter
- #27
After a huge delay (kid stuff) I've been working at this again. Latest modification is to the stock hellfire trunnion pins. I've never been a fan of the way Billy did it. I understand why he did, primarily for ease of adjustment and given his assumed target market, KOH or strictly offroad or trailered, it makes sense. But for me I plan to drive this on the street fairly often and was worried that the little bit of play that would be certain would work its way into a larger problem and possibly affect steering.
First step was to design a replacement trunnion pin using while still using the Hellfire steering arm.
I came up with the following design (which was tweaked here and there during machining). This design effectively locks the trunnion pin to the steering arm like toyota did it.
Pictures from the partially machined parts are shown below.
Machining out the setscrew and counterbore with a taper for a custom 4340 Sy=120ksi taper lock trunnion pin.
New trunnion pin beside original Hellfire Design. Note that trunnion pin still needs a 3/4-16 thread put on it to hold it into the steering arm. Pictures tomorrow. You can see that at the same time I upgraded the 20mm bore trunnion bearing to the 25mm bore one. This should provide the strength for steering forces into this trunnion. If anyone is curious the taper was designed using some literature I found for ball joint tapers.
First step was to design a replacement trunnion pin using while still using the Hellfire steering arm.
I came up with the following design (which was tweaked here and there during machining). This design effectively locks the trunnion pin to the steering arm like toyota did it.
Pictures from the partially machined parts are shown below.
Machining out the setscrew and counterbore with a taper for a custom 4340 Sy=120ksi taper lock trunnion pin.
New trunnion pin beside original Hellfire Design. Note that trunnion pin still needs a 3/4-16 thread put on it to hold it into the steering arm. Pictures tomorrow. You can see that at the same time I upgraded the 20mm bore trunnion bearing to the 25mm bore one. This should provide the strength for steering forces into this trunnion. If anyone is curious the taper was designed using some literature I found for ball joint tapers.
Last edited:
- Thread starter
- #28
Finished the pins tonight minus torquing to 200 ft-lb and drilling the cotter pins. From now on this is setup as per toyota oem procedure.
View showing both top and bottom of the modified pins. Stock vs oversized bearing for reference.
One disassembled to show concept better.
Axle housing is essentially completed with all tabs etc welded. I'm not adding knuckle ball gussets as my goal is not ultimate strength but to build a rig for expedition style use with my kids.
One thing I'd like to mention, I haven't threaded in a lathe since high school like 20 years ago so I'm by no means a pro. Rather a hobbyist with passion and one who invests as much time reading books and doing research as time in the shop so if you notice errors they are part of my education... For example it took me ~15 hours of shop time and probably 10 hrs design to make the 2 pins and bore the steering arms! Cost was very low though.
View showing both top and bottom of the modified pins. Stock vs oversized bearing for reference.
One disassembled to show concept better.
Axle housing is essentially completed with all tabs etc welded. I'm not adding knuckle ball gussets as my goal is not ultimate strength but to build a rig for expedition style use with my kids.
One thing I'd like to mention, I haven't threaded in a lathe since high school like 20 years ago so I'm by no means a pro. Rather a hobbyist with passion and one who invests as much time reading books and doing research as time in the shop so if you notice errors they are part of my education... For example it took me ~15 hours of shop time and probably 10 hrs design to make the 2 pins and bore the steering arms! Cost was very low though.
- Thread starter
- #29
A little more progress. I'm posting to let anyone know that there is a potential trunnion bearing interference with the hellfire knuckles. It would depend on the casting and machining of course but on mine there was an interference that wasn't that noticeable when assembled.
Lower bearing hitting on casting.
Diegrinding to provide necessary clearance.
Lower bearing hitting on casting.
Diegrinding to provide necessary clearance.
- Thread starter
- #30
Tonight I welded the steering inserts in the Hellfire arms. Not sure what others do but I used 3/32 E7018 rods and heated them to 700F for one hour to burn off potential moisture in the flux. Used DCEP stick at about 90 amps. Seemed to work really good.
I assembled the knuckles first using a setup bearing in upper trunnion (with inner and outer races ground so they would slide together with no force). This allowed me to get the shims selected with 5 to 6 lbs knuckle preload, low end of FSM spec.
Then I swapped out the bearing for the proper ones and it went together using my version of the SST. Clamp and 2 sockets.
Checking preload after everything torqued.
The axle in its current state.
Guard
I assembled the knuckles first using a setup bearing in upper trunnion (with inner and outer races ground so they would slide together with no force). This allowed me to get the shims selected with 5 to 6 lbs knuckle preload, low end of FSM spec.
Then I swapped out the bearing for the proper ones and it went together using my version of the SST. Clamp and 2 sockets.
Checking preload after everything torqued.
The axle in its current state.
Guard
- Thread starter
- #32
I don't know about the degrees. I'm just setting the turning degrees to the FSM 80 series value. If I go more maybe the birfs are weaker at full lock and I'd rather be stronger.
This is an awesome/ very stout setup. For those that think they could build a dana 60 for what this whole thing probably cost: dana 60 RCVs are $2300, then you have to add everything else. This route provides phenomenal strength, and does so reasonably.
We don't really need to clog up this thread, but it's worth it to note that a built LC axle like this is as strong as a stock D60, not a built D60. Built D60s are hella expensive, no one is disputing that.
Yup, and a stock dana 60 is strong as hell.
- Thread starter
- #36
As long as it is strong enough to drive around woods roads with my kids I'll be happy.
Drilled and tapped holes in the hellfire knuckles for the OEM grease ports. They are not in the exact OEM location but fairly close and there at least 3/4" of thickness to the casting there so it shouldn't be a problem. I didn't want to be without a way to add grease in case some makes it past the wiper/felt.
Heated and hammered the dust shields so they would fit on the knuckles. Not sure I'll keep these long term but again wanted the option of having them. If rocks tend to get stuck or something I can cut them off.
My 5 yr old son helped me install and torque the purchased diff cover. I believe it is 1/4" but I don't know who makes it because I bought it with a bunch of parts. In case someone else has one of these. I had to do some custom grinding where the 3rd member protrudes through because it was hitting the cover.
Drilled and tapped holes in the hellfire knuckles for the OEM grease ports. They are not in the exact OEM location but fairly close and there at least 3/4" of thickness to the casting there so it shouldn't be a problem. I didn't want to be without a way to add grease in case some makes it past the wiper/felt.
Heated and hammered the dust shields so they would fit on the knuckles. Not sure I'll keep these long term but again wanted the option of having them. If rocks tend to get stuck or something I can cut them off.
My 5 yr old son helped me install and torque the purchased diff cover. I believe it is 1/4" but I don't know who makes it because I bought it with a bunch of parts. In case someone else has one of these. I had to do some custom grinding where the 3rd member protrudes through because it was hitting the cover.
- Thread starter
- #37
Painted and filled with oil, oil being a very important step. One thing many probably won't like are the 6 to 8 bolt adapters but I need them for the HMMWV double bead lock wheels and tires.
Far side tie rod end is not tight in the above picture.
I'll post one last picture mounted with the wheels on.
Far side tie rod end is not tight in the above picture.
I'll post one last picture mounted with the wheels on.
Those look to be the same type of wheel adapters I've been trying to sell.
cwwfj60
Supporting Vendor
very cool build! I love that diff cover, been thinking about doing something like that for a while, now I know what it should look like!
Hi,
Wish I had your fab talents. No way I could do something like this. I am curious about your diff cover, though. Besides being bad ass. I could swear that my stock 40 diff cover has the oil fill aligned about at the lower edge of the axle. Your oil fill hole looks to be aligned about at the top of the axle tube unless it is just the perspective of the photos. Do the 60/80 axles like a higher level of oil?
Wish I had your fab talents. No way I could do something like this. I am curious about your diff cover, though. Besides being bad ass. I could swear that my stock 40 diff cover has the oil fill aligned about at the lower edge of the axle. Your oil fill hole looks to be aligned about at the top of the axle tube unless it is just the perspective of the photos. Do the 60/80 axles like a higher level of oil?
