V8, splitcase 38”

[archie40]

So I’m dreaming of the next build while I wait to get time to put the other two projects on the road. In the wings I have an fj45 that I want to build into a capable street/trail rig that can handle sand hollow and Moab’s non buggy trails. Current plan starts with likely a 5.3/6.0 and ends with 38’s. In between is likely a 4l80 for simplicity. Next inline is the question for today: how will a splitcase hold up in between a modest LS and 38’s. Driving style is more crawl then throttle junky. That being said, occasionally it feels right to throttle out.

Will a splitcase hold up to that kind of abuse?

 

[350TacoZilla]

Can't help you there but I will say for a light rig and a sensible driver I wouldn't write off a 4.8, 4l60E combo. Deeper 1st gear and taller OD. You didn't mention gearing so I just ran 2 different numbers to get an idea.

with a true 38" tire here is 70mph
---------[4l60E]----------[4l80E]---------
5.29s=2292rpm---------2456rpm
7.17s=3106rpm---------3328rpm

 

[archie40]

Can't help you there but I will say for a light rig and a sensible driver I wouldn't write off a 4.8, 4l60E combo. Deeper 1st gear and taller OD. You didn't mention gearing so I just ran 2 different numbers to get an idea.

with a true 38" tire here is 70mph
---------[4l60E]----------[4l80E]---------
5.29s=2292rpm---------2456rpm
7.17s=3106rpm---------3328rpm

That’s good to know, thanks for running the numbers. Truth be told, I was just throwing that transmission out there as it was in my head at the moment. I’m pretty sure I want to try an auto on this project.

Current rig is a 5.3/SM465/orion/4.11/35’s. Drivetrain wise, it’s perfect. Great street driving and slow in the rocks. The next rig I want longer/wider for the stability. On ‘Mud the splitcase is held to a lofty place. The ability to stuff 4:1 in it is definitely a selling point. For my style I don’t think I’ll need a doubler with proper gearing. The down side of the splitcase is it requires passenger side drop front and rear. This leads me to fj80 (desired width) axles or cut N paste tons. None of it is cheap, so I’m trying to make my mind up on the splitcase.

 

[350TacoZilla]

I would think 38s, V8 and 4:1 might start being the upper end of what the toy axles would like anyhow. At that point I think money spent on the 1 tons would be well spent. 99-04 SD axles are narrower and cheaper than the 05+ stuff and you could redrill down to 6x5.5 if you already had wheels you wanted to run. At that point I would maybe just grab a Rubicon 4:1 241 and keep driver side drop axles, saving you money. I know thats a lot of moving the goal posts but it might save $ in the end.

 

[Aisin]

These guys did it almost 20 years ago. Tundra V8, Marlin duals and 42s. Picture was taken in 2008.

 

[archie40]

I would think 38s, V8 and 4:1 might start being the upper end of what the toy axles would like anyhow. At that point I think money spent on the 1 tons would be well spent. 99-04 SD axles are narrower and cheaper than the 05+ stuff and you could redrill down to 6x5.5 if you already had wheels you wanted to run. At that point I would maybe just grab a Rubicon 4:1 241 and keep driver side drop axles, saving you money. I know thats a lot of moving the goal posts but it might save $ in the end.

Believe me, I’m tempted by the tons argument. Seems like price wise is about the same- narrowing and offsetting vs building a 9.5 front&chromo for the full floater rear. I don’t “think” I want fullwidth axles. For my desires and style, I’m pretty confident that I could keep the Toyota axles alive. I feel like the advantage to the lc stuff is slightly lighter weight. Small bonus for staying Toyota, but not a huge factor for me. Advantage to the tons is availability of parts. From my back of the napkin calculations, they pencil out pretty close price wise. LC wins labor wise (the rear doesn’t need to be modified outside of axle shafts)and I’ll have matching thirds. I currently have 3 4.11 diffs. Of coarse tons are the beefiest. Like I said I am not set on lc yet.

This is all part of my question on the splitcase strength. If I decide to stick with a splitcase, I’m tied to offset axles which should be fine. BUT future proofing and all…

 

[archie40]

These guys did it almost 20 years ago. Tundra V8, Marlin duals and 42s. Picture was taken in 2008.

And the splitcase held up? This is the kind of thing I’m hoping to hear. Or “cut you losses and go big.”

 

[Aisin]

Yes. Of course the cases were full of all the aftermarket parts Marlin had for Toyota cases at the time. Competition gears and chromo 30 spline output/input shafts. I’m sure there was more. Pretty sure Marlin doesn’t sell any of those parts anymore. His ****head kid won’t even stock dual case adapters 99% of the time.

 

[archie40]

Yes. Of course the cases were full of all the aftermarket parts Marlin had for Toyota cases at the time. Competition gears and chromo 30 spline output/input shafts. I’m sure there was more. Pretty sure Marlin doesn’t sell any of those parts anymore. His ****head kid won’t even stock dual case adapters 99% of the time.

This brings us back to the stock outputs and a 4:1 set of gears. Is this a reliable case?

 

[Bebop]

No it's not.
I would get a Dana300 and add bigger outputs or a NP271 if you're tight.
Atlas if you can, they pop up used from time to time.

 

[Diablo169]

These guys did it almost 20 years ago. Tundra V8, Marlin duals and 42s. Picture was taken in 2008.

I feel like that rock is still there, or a similar one replaced it.

 

[Sluggy]

Well ya it's the last part of wh1...

 

[archie40]

I would think 38s, V8 and 4:1 might start being the upper end of what the toy axles would like anyhow. At that point I think money spent on the 1 tons would be well spent. 99-04 SD axles are narrower and cheaper than the 05+ stuff and you could redrill down to 6x5.5 if you already had wheels you wanted to run. At that point I would maybe just grab a Rubicon 4:1 241 and keep driver side drop axles, saving you money. I know thats a lot of moving the goal posts but it might save $ in the end.

So the driving desire on the splitcase/FJ80 axles is the width. I don’t want full width axles under this build. These axles give just the right width in my mind. AND I do have a set of 6x5.5 beadlocks sitting idle, so it’d be nice to use them.


BUT

Let’s say I do go tons. I’d be narrowing them- I’m not scared, but I’ve never done it either. Seems like a good bit of work and I end up with custom shafts. Cost to build a mid level set of tons (I’d likely just get 05’s) seems comparable to built FJ80. You do end up with a stronger axle. Probably a good bit heavier. I’ve watched a couple Utube videos- is it that easy?

I’d have to do some research on the 241j case. I think it’s 4.1? How stout is it? Seems like $1500 for a pulled unit no mention of condition. How stout are they ? Am I better off good to for an Atlas at the point($$$)?

 

[350TacoZilla]

So the cheapest way to narrow it would be find a off the shelf inner shaft that would be short enough that you just narrow the tube an drop in the new shaft but I don't know what all is out there. Next is if you can respline the stock sha be shorter.

Either way the cheap way to do the housing is cut the tube then sleeve it before welding back together. And the more expensive method is cut the outer C off and have it machined out to fit back onto end of tube and reweld it on.

I mentioned the 99-04 since they are less desirable so cheaper and easy to find, they also start out already narrower than the 05+ stuff so ran with a deep backspacing wheel can tuck them in better for not much money. If you were thinking about running FJ80 axles you already have that would make sense but if you are looking to buy axles either way I would spend the money towards tons especially if you can get them cheaper than the toyota axles.

This dude has a really interesting thread on the superduty D50 and honestly I have went from thinking it was a throw away axle from listening to people to seriously considering getting one for a future project after reading this thread-->Lets hit the dumbfuck sauce and build a stupid front axle( Shaved narrowed Dana 50)

241 is a good case and is stronger than the old np208 and such but less than 271's, they are a smaller case so they fit easier and if you get one with 4:1 it can make up for the gearing in axles. Though again depending on what you buy superduty d60's are available in everything from 3.23-5.38 I think? (99-04 F450-550 D60 V10 trucks) If you don't already know don't get fooled into thinking the 450-550 means its a Super60 axle, those are only 05+ an the 99-04 is all D60 front in those trucks.

 

[archie40]

So the cheapest way to narrow it would be find a off the shelf inner shaft that would be short enough that you just narrow the tube an drop in the new shaft

Ideally, yes. I’ll have to look into this possibility.

Either way the cheap way to do the housing is cut the tube then sleeve it before welding back together.

This the YouTube way. I need to get my hands on alignment bar and pucks….

And the more expensive method is cut the outer C off and have it machined out to fit back onto end of tube and reweld it on.

Above my pay grade. ..

I mentioned the 99-04 since they are less desirable so cheaper and easy to find, they also start out already narrower than the 05+ stuff so ran with a deep backspacing wheel can tuck them in better for not much money.

I’ll look into this option

-->Lets hit the dumbfuck sauce and build a stupid front axle( Shaved narrowed Dana 50)

more study material, I’ll get cracking

241 is a good case and is stronger than the old np208 and such but less than 271's, they are a smaller case so they fit easier and if you get one with 4:1 it can make up for the gearing in axles.

More things to study.

Thanks I appreciate the advise. I’m not anywhere near purchasing anything, so I’m ready to learn.

 

[Oddball]

Either way the cheap way to do the housing is cut the tube then sleeve it before welding back together. And the more expensive method is cut the outer C off and have it machined out to fit back onto end of tube and reweld it on.

I would say, method two is not the expensive way, but the cheapest way and best way. Cut the C off, remove the piece of tube from the C, and then heat shrink it back on and weld. No machining, no sleeve. The C is also bound to be square as it will slip on with only a few thousandths before it shrinks. Only thing to screw up is caster.