Builds The LF40 Wheeler Build - Twin Turbo & 8 Speed Auto FJ40 (8 Viewers)

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

That's not a doubler transfer case. That's a three speed transfer case. High, medium, low, no "doubling" at all.

It should be the same, though. Same overall crawl. It essentially doubles the ratio in the case.
 
Last edited:
5.61 × 5.44 (total case reduction) x 5.29 is still ~160:1, but it has the intermediate gear of 2.5:1, so it acts like a normal low in medium, and doubled in low.
 
I see your point. In that case (ha) an atlas two speed can be had in the same 5:1ish low range.
 
That is a expensive option but a cool one.

I am interested in your 4 link rear solution. I am building a LS/NV4500/3.8 Atlas in my 73 and have been contemplating a rear link setup. I would love to have a 2.5 and a 5.44 low but my atlas fell into my lap for a steal and i dont really want to add the length of a range box in there.

I have thought about using an electric fan and moving the entire drive train forward but it would be alot of work for brobably only 1-2" worth of gain.
 
I see your point. In that case (ha) an atlas two speed can be had in the same 5:1ish low range.

The only thing I don't like about the single low is the fact that it's so dang slow all of the time. My normal 80:1 single low is good for most stuff, but having that extra crawl can be really nice when you do need it.
 
That is a expensive option but a cool one.

I am interested in your 4 link rear solution. I am building a LS/NV4500/3.8 Atlas in my 73 and have been contemplating a rear link setup. I would love to have a 2.5 and a 5.44 low but my atlas fell into my lap for a steal and i dont really want to add the length of a range box in there.

I have thought about using an electric fan and moving the entire drive train forward but it would be alot of work for brobably only 1-2" worth of gain.

I really wish they had a trail series of that case. I don't need all 300M internals, or gears that big, but those are bouncer and ultra 4 cases. I really love my doubler setup, it's just long. If I could find a cheap atlas, I would totally go for it, but I would much prefer to have the doubler if I have the option. Funny enough, the "short" Atlas 2 is ~11.5" (depending on flange), that Hero case is 12.5" long. Pretty dang similar, besides the internals.

Linking it won't be bad at all. I'll run a double triangulated 4 link, I'll probably build a flat drop skid and mount my lowers there, and add in another bar for my uppers. I'll move my lower fronts then as well. Coilovers are the slightly tricky part. I think I can shove some King 2.0 10" in the wheel wells, may be able to squeak 12"s in there, outside the frame. Really though, I'd rather build more of a faux trailing arm lowers and run shorter coilovers higher up on the arm, so I can get a bit more up-travel and droop out of a better fitting shock. I may need to screw with the rear fame a bit by notching it, but they should clear.
 
Last edited:
I really wish they had a trail series of that case. I don't need all 300M internals, or gears that big, but those are bouncer and ultra 4 cases. I really love my doubler setup, it's just long. If I could find a cheap atlas, I would totally go for it, but I would much prefer to have the doubler if I have the option. Funny enough, the "short" Atlas 2 is ~11.5" (depending on flange), that Hero case is 12.5" long. Pretty dang similar, besides the internals.

Linking it won't be bad at all. I'll run a double triangulated 4 link, I'll probably build a flat drop skid and mount my lowers there, and add in another bar for my uppers. I'll move my lower fronts then as well. Coilovers are the slightly tricky part. I think I can shove some King 2.0 10" in the wheel wells, may be able to squeak 12"s in there, outside the frame. Really though, I'd rather build more of a faux trailing arm lowers and run shorter coilovers higher up on the arm, so I can get a bit more up-travel and droop out of a better fitting shock. I may need to screw with the rear fame a bit by notching it, but they should clear.
yeah i figure my 2nd gear would be about half of the granny 5.61 at 3.06 so forward you kind of have a half low but reverse is only one speed. I had a 22r dual case before on 5.29's but i am thinking with the added torque of the v8 i probably don't need to be wound up as much making it feel much lower geared.

Have you thought of running a lower triangulated and upper parallel rear 4 link and use the uppers as the "trailing arm" to mount the coils? I know Dirthead Dave did something similar with his moms spaghetti build with air bags. I have seen some other go fast ultra 4 type builds this way too to keep the shocks up out of the way. dual triangulated is ideal but i have seen the semi trangulated work well as well. I have a full width rear axle though too so a little more room outside the frame rail( widened fzj80 fullfoat). a skinnier axle could make outside the frame rail a little more tight.

Could have fun with some cantilever setup too if you want but that can get complex.
 
If I add like 100lbs or more of anything in the back of my 40 I can definitely feel it. 40s are really sensitive to weight. Especially in places like moab trying to ascend ledges. On any tough obstacles anybody sitting in the back I make get out. I was hesitant to add the 4plus bumper on the back due to its weight but i decided i value its protection of the body on my cruiser more. But its hampered my ascents. I've thought about deleting my spare also. Quite a few guys go without a spare or with a lighter spare. But I get pretty far out in the middle of nowhere. In my scale radio control crawler its really cool because I can mess with weight bias to see what works best. Seems like removing weight from the rear helps a lot too on small scale as well. On pirate4x4 I remember a wrangler guy made his little kids get out of the back of his jeep so he could make it to the top of a steep rock slab lol. They are pretty similar in dimensions to a 40.
Gas tank in the rear won't impact wheeling ability in any significant way. Put it wherever is most convenient for the size tank you need.
 
If I add like 100lbs or more of anything in the back of my 40 I can definitely feel it. 40s are really sensitive to weight. Especially in places like moab trying to ascend ledges. On any tough obstacles anybody sitting in the back I make get out. I was hesitant to add the 4plus bumper on the back due to its weight but i decided i value its protection of the body on my cruiser more. But its hampered my ascents. I've thought about deleting my spare also. Quite a few guys go without a spare or with a lighter spare. But I get pretty far out in the middle of nowhere. In my scale radio control crawler its really cool because I can mess with weight bias to see what works best. Seems like removing weight from the rear helps a lot too on small scale as well. On pirate4x4 I remember a wrangler guy made his little kids get out of the back of his jeep so he could make it to the top of a steep rock slab lol. They are pretty similar in dimensions to a 40.

The longer wheelbases sure don't seem to feel it as much, but I can definitely feel it in the 40, though.
 
Well, I finally got around to changing out my shackle and leaf bolts and moving my links around a bit.

New 4 1/2" x 5/8 bolts for the shackles. My previous ones were about a quarter inch short, and I had one nut back off (Thanks for the magic bag of hardware that saved me, @Godfather90) at SAS this year, so I just cranked them down till I got around to changing them out.

20211217_161847_50.jpg


20211217_161813_50.jpg


I got my upper link moved up higher. Hopefully, I can limit the unloading on big climbs, now. I'm probably going to turn my 8274 into a suckdown since I have in-cab controls for it anyways.

20211216_154649_50.jpg


20211216_154715_50.jpg


And a picture of the herd hiding in the garage.

20211217_161948_50.jpg
 
Drive train length info. I moved my radiator from the face of the core support to inside the core support and installed an 2300cfm electric slim fan on it and gained a little over 4in of rear drive shaft. My electric fan mounted that way is shorter than the radiator mounted to the face if that makes sense. I am ZERO help on your doubler or hero case I am running a TH350 with Atlas 4.3 without speedometer so its the shortest T/case I could find. I am not linked tho I am running SOA/SR with flipped springs and front axle mounts pushed forward 105 in wheel base on 40's and it wheels very well for what I do.
 
Drive train length info. I moved my radiator from the face of the core support to inside the core support and installed an 2300cfm electric slim fan on it and gained a little over 4in of rear drive shaft. My electric fan mounted that way is shorter than the radiator mounted to the face if that makes sense. I am ZERO help on your doubler or hero case I am running a TH350 with Atlas 4.3 without speedometer so its the shortest T/case I could find. I am not linked tho I am running SOA/SR with flipped springs and front axle mounts pushed forward 105 in wheel base on 40's and it wheels very well for what I do.

I wish I could move everything forward more. My radiator and condenser already is as far forward as I can get it to the front clip, as I used an oversized radiator, so I moved it all when I had the chance. An electric fan is a lot of work for maybe 1" - 1.5" of clearance to move forward, but it would be worth it if I could get more. My wheel base is a bit shorter than yours, about 99"-100".

Thanks for the info!
 
I wish I could move everything forward more. My radiator and condenser already is as far forward as I can get it to the front clip, as I used an oversized radiator, so I moved it all when I had the chance. An electric fan is a lot of work for maybe 1" - 1.5" of clearance to move forward, but it would be worth it if I could get more. My wheel base is a bit shorter than yours, about 99"-100".

Thanks for the info!
I’m not saying 1-1.5 is worth it to you, but they aren’t that hard. They just aren’t that hard. I’m using a Taurus fan and like it, but there are a lot of options in the aftermarket.
 
I’m not saying 1-1.5 is worth it to you, but they aren’t that hard. They just aren’t that hard. I’m using a Taurus fan and like it, but there are a lot of options in the aftermarket.

Moving it wouldn't be hard, it just having to move everything for 1 - 1.5 just isn't worth it. I'd rather change cases if I'm doing anything.
 
Well, I finally got around to getting new wheels and tires so I can go snow wheeling (if there was snow)

Anyways, I made a mall crawler.

New 37 × 12.5 × 17 KO2s

I'm not super in love with the look, but the on-road performance and snow traction is well worth it to me.

20211224_110225.jpg


20211224_110304.jpg

20211224_110236.jpg


I went with Pro Comp steel crawler wheels, since they were on sale at 4WP, and I like the looks. They are also lower offset which is nice for a road wheel.

20211224_095527.jpg


20211224_095534.jpg


Anyways, I seem to have a habit of replicating @Godfather90 :rofl:
 
Last edited:
We have those super on all out work trucks. Not cheap but they do really well. Don’t they salt the roads down there?

They do, but there is no snow, so it doesn't really matter anyways. I usually trailer to trails anyways, but my Krawlers aren't siped, and I wanted a better road tire for all the street driving around town I do anyways.
 
My krawlers do really well in the snow, but they are siped and I run very low pressures. I hear the red label tread does terrible in snow. I'm sure the on road performance of those all terrains is nice.

I was wondering about that. Which compound are you running right now? I was debating siping the Krawlers, but I don't like burning them up on the road too much.
 
I was wondering about that. Which compound are you running right now? I was debating siping the Krawlers, but I don't like burning them up on the road too much.
I've always used blues. Less schwab does siping. The blues will last a long time so you won't burn them up quickly as long as you don't have the toe off or something. However replacement new krawlers are very expensive so it's still wise to conserve them. Siping should help them in the rocks too I think personally.
 

Users who are viewing this thread

Back
Top Bottom