Rear FJ60 Leaf Springs on my FJ40 (2 Viewers)

[Cruzur40]

Hello all,
I'm a newbie, so please go easy. I have a 72 FJ40 project I'm basically just starting. This is a resto-mod and I'm doing a 2001 LM7 and full width axles. My specific question is this. I hear or have read where a popular swap is putting FJ60 rear leaf springs on the rear of the 40. My install will be a Spring over as I plan on 3 linking the front with coil overs. Specifically my question for those that have done this or seen it done here, can you give detailed specifics as far as springs to use, flat or lifted, spring count you used , did you relocate your rear hangers and what length shackles did you use? Or if someone can point me to a thread with this info I would be very grateful. TIA!

 

[too tall]

Personally, I'd link the rear and leave the front on leafs. I'm biased though. I know there is probably packaging issues with the full width front under your rig.
I have used 60 series rear springs in the back of a 40 series. I like to mount the hangers where toyota did on the 60 frame. I can't remember the actually measurement right now?
It depends on what you want to run the wheelbase at but I have redrilled the military wrap and flipped the packs before end for end to get more wheelbase as the centre pins are offset. As far as shackles, Again I like to use the ones that the springs came with -60 series rear shackles.

 

[Cruzur40]

Personally, I'd link the rear and leave the front on leafs. I'm biased though. I know there is probably packaging issues with the full width front under your rig.
I have used 60 series rear springs in the back of a 40 series. I like to mount the hangers where toyota did on the 60 frame. I can't remember the actually measurement right now?
It depends on what you want to run the wheelbase at but I have redrilled the military wrap and flipped the packs before end for end to get more wheelbase as the centre pins are offset. As far as shackles, Again I like to use the ones that the springs came with -60 series rear shackles.

I'm wanting to stretch it as far as possible. I've seen this same set up I'm trying to do and the guy got about 104"-105" out of it when they were flipped around which is my plan. He also pushed the front out when he 3 linked it. Can you explain the military wrap process and what that does?

 

[Firemedic831]

Link the rear.

 

[Cruzur40]

Link the rear.

That's the plan eventually.

 

[pjohnson]

With the fabrication you are already doing to go full width, I would replace the spring and shackle hangars and outboard them. This will give you a better, more stable ride. In addition, for spring over axle, you want flat springs for the same reasons.

 

[Cruzur40]

With the fabrication you are already doing to go full width, I would replace the spring and shackle hangars and outboard them. This will give you a better, more stable ride. In addition, for spring over axle, you want flat springs for the same reasons.

I like it

 

[too tall]

I'm wanting to stretch it as far as possible. I've seen this same set up I'm trying to do and the guy got about 104"-105" out of it when they were flipped around which is my plan. He also pushed the front out when he 3 linked it. Can you explain the military wrap process and what that does?

You flip the military wrap (2'nd spring from the top) to retain extra security if the main leaf breaks. The military wrap is there to keep the axle in place when the main leaf fails. The military wrap is located at the fixed end where there is no shackle.

 

[65swb45]

For Sale - SoCal: stretched wheelbase 40 custom rear springs

Mfgr unknown. Came to me as you see them, and were removed by the current owner for a 4link. Springs measure 46.5" eye to eye and 24.5" from forward end to center pin. Take standard size hanger pins (included) and have boomerang shackles for the rear. $150 as-is, where is. You're welcome to...

forum.ih8mud.com

 

[Cruzur40]

You flip the military wrap (2'nd spring from the top) to retain extra security if the main leaf breaks. The military wrap is there to keep the axle in place when the main leaf fails. The military wrap is located at the fixed end where there is no shackle.

Do you have any pics of your set up?

 

[lcwizard]

I'm wanting to stretch it as far as possible. I've seen this same set up I'm trying to do and the guy got about 104"-105" out of it when they were flipped around which is my plan. He also pushed the front out when he 3 linked it. Can you explain the military wrap process and what that does?

We did a lot of rock crawling in competition. I agree with @too tall , link the rear , the front is less critical. Pushing the front out too far will just take weight off the
front axle . Your front will get no traction in climbs. Linking the rear will let you push the rear back a bit farther than you can with leaves and pushing the rear back aids in climbs. 2F, stock wheelbase cruisers usually do better at climbs than a V-8 swapped cruiser simply because the 2F puts an extra 250 lbs of mass over the front axle.
I sheared a rear pinion on Hole in The Rock trail and had to exit without rear wheel drive. I had a full floater in my 60 so I disassembled the rear on the trail, pulled the axles
and drove out. It had a 350. Even with an ARB in the front , every steep climb had to be done in reverse. Absolutely useless going forward.
Unless you're building this truck for desert racing I'd keep the front axle push to a modest or minimum amount

 

[MOTOV8R]

I put some rear 60 springs on the front of a troopy, i wanted the longer springs. The pic shows SOA (axle was upside down to check fit) but I ended up going SUA and put the upper shackle hole through the frame to get less lift.

 

[too tall]

Do you have any pics of your set up?

I just looked in my library and I don't actually. I can try to grab a couple tomorrow evening.

 

[Cruzur40]

I just looked in my library and I don't actually. I can try to grab a couple tomorrow evening.

Thanks!

 

[Cruzur40]

I put some rear 60 springs on the front of a troopy, i wanted the longer springs. The pic shows SOA (axle was upside down to check fit) but I ended up going SUA and put the upper shackle hole through the frame to get less lift.

View attachment 3269434

View attachment 3269435

how is the ride with those on the front?

 

[Cruzur40]

We did a lot of rock crawling in competition. I agree with @too tall , link the rear , the front is less critical. Pushing the front out too far will just take weight off the
front axle . Your front will get no traction in climbs. Linking the rear will let you push the rear back a bit farther than you can with leaves and pushing the rear back aids in climbs. 2F, stock wheelbase cruisers usually do better at climbs than a V-8 swapped cruiser simply because the 2F puts an extra 250 lbs of mass over the front axle.
I sheared a rear pinion on Hole in The Rock trail and had to exit without rear wheel drive. I had a full floater in my 60 so I disassembled the rear on the trail, pulled the axles
and drove out. It had a 350. Even with an ARB in the front , every steep climb had to be done in reverse. Absolutely useless going forward.
Unless you're building this truck for desert racing I'd keep the front axle push to a modest or minimum amount

My intention is to do King Coil overs in the front with the 3 link. I worry about linking the rear with Large coil overs and eating into space in the rear wheel well and next to the rear bench seat where my kids will ride. This isn't going to be a competition rig. I'm looking at 60% street and beach and 40% medium to difficult trail time. I want an extremely capable trail rig with a comfortable street ride and be able to lug my 2 small kids in the back. in both places.

 

[Half Wacked aka Split Pea]

I had 60 springs in rear and coil overs in front work great, don’t outboard springs, my 2cents I had full hydro steering, but with limited straps you could still run your power steering box

 

[EWheeler]

Hello all,
I'm a newbie, so please go easy. I have a 72 FJ40 project I'm basically just starting. This is a resto-mod and I'm doing a 2001 LM7 and full width axles. My specific question is this. I hear or have read where a popular swap is putting FJ60 rear leaf springs on the rear of the 40. My install will be a Spring over as I plan on 3 linking the front with coil overs. Specifically my question for those that have done this or seen it done here, can you give detailed specifics as far as springs to use, flat or lifted, spring count you used , did you relocate your rear hangers and what length shackles did you use? Or if someone can point me to a thread with this info I would be very grateful. TIA!

Spring over use stock flat springs. You can flip the pack and re-drill the military wrap leaf for more wheelbase stretch. I have this setup on my ‘80 FJ40. Choose wheelbase desired, and work backwards to figure out where your fixed end hanger will live. This assumes you arent reusing the factory spring hangers. I did not. Shackle length is fully dependent on where you want your shackle hanger to live and ride height. You want shackle angle to be around 45 degrees or so. I removed a leaf or maybe two from the pack, but do not recall which ones, its been over a decade since i built the truck. Spring over in rear will require an anti wrap bar.

 

[EWheeler]

Hello all,
I'm a newbie, so please go easy. I have a 72 FJ40 project I'm basically just starting. This is a resto-mod and I'm doing a 2001 LM7 and full width axles. My specific question is this. I hear or have read where a popular swap is putting FJ60 rear leaf springs on the rear of the 40. My install will be a Spring over as I plan on 3 linking the front with coil overs. Specifically my question for those that have done this or seen it done here, can you give detailed specifics as far as springs to use, flat or lifted, spring count you used , did you relocate your rear hangers and what length shackles did you use? Or if someone can point me to a thread with this info I would be very grateful. TIA!

Old incomplete build thread on my ‘80 40, but some details on what i did on the rear suspension are still there

The Asian Mistress 40 Build

I used some all thread to aid in the alignment of the hangers, along with some plumb bobs. Once the axle was in position, I welded the perch on with some gussets. I also welded up the seams on the inside of the frame between the frame rail & the inner boxing but didn’t snap any pictures.

www.pirate4x4.com

 

[EWheeler]

We did a lot of rock crawling in competition. I agree with @too tall , link the rear , the front is less critical. Pushing the front out too far will just take weight off the
front axle . Your front will get no traction in climbs. Linking the rear will let you push the rear back a bit farther than you can with leaves and pushing the rear back aids in climbs. 2F, stock wheelbase cruisers usually do better at climbs than a V-8 swapped cruiser simply because the 2F puts an extra 250 lbs of mass over the front axle.
I sheared a rear pinion on Hole in The Rock trail and had to exit without rear wheel drive. I had a full floater in my 60 so I disassembled the rear on the trail, pulled the axles
and drove out. It had a 350. Even with an ARB in the front , every steep climb had to be done in reverse. Absolutely useless going forward.
Unless you're building this truck for desert racing I'd keep the front axle push to a modest or minimum amount

Love it. What is your experience and opinion on forward shackle vs shackle reversal for crawling/wheeling?