My goal. Fj60 6bt nv4500 dd/ expedition ready. Reliability is a must. I have read a few threads for 6bt swaps it seems that folks go with soa and beef up the springs. How are these axles holding up in the long run say 2k down the road? Also is there a recommended stronger axle swap to eliminate possible future failure?
Stock axle under 6bt (1 Viewer)
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A 6BT is cool and all that but a 4BT is a much easier swap. I'm running an intercooled 4BT with a NV4500 trans in my FJ62 and I have plenty of power. If you're going for reliability I think the 4BT is a better choice because it will put much less stress on the drivetrain and chassis. For the ultimate reliability a Toyota diesel would probably be the best if you can find one. Just my $.02.
Nothing wrong with the stock axles, many 4B and 6B swaps in 40s, 60s, and 80s that have been operating fine on the Yota axles. Unless you are doing some extreme, hardcore rock crawling stuff.
As far as the SOA and upgraded suspension, I don't know specifically with the 60 but with the 80 you have to add 4" of lift to clear the oil pan and the axle with the 4B, friggin tall motor fo' sho.
As far as the SOA and upgraded suspension, I don't know specifically with the 60 but with the 80 you have to add 4" of lift to clear the oil pan and the axle with the 4B, friggin tall motor fo' sho.
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Are you planning on tuning up the 6bt at all? Or is it stock?
The first generation 6BTs come stock with 400 ft-lbs torque, if you were going to bump up the power, or lock the axles, I would recommend getting some longfields for the front.
I am doing the same swap. I am going to put a 14 bolt in the rear though due to the fact that I am going to bump the HP to around 275
The first generation 6BTs come stock with 400 ft-lbs torque, if you were going to bump up the power, or lock the axles, I would recommend getting some longfields for the front.
I am doing the same swap. I am going to put a 14 bolt in the rear though due to the fact that I am going to bump the HP to around 275
put it this way, Dodge used to have Dana 60's in the rear of the first gen Cummins truck. There were too many failures so the next gen had 70's in the 3/4 and 80's in the 1 tons.
A 35 spline dana 60 would hold if you weren't doing excessive towing. Most of the Dodge failures were towing related.
I've broke at least one of every axle in land cruisers behind a 2F
A 35 spline dana 60 would hold if you weren't doing excessive towing. Most of the Dodge failures were towing related.
I've broke at least one of every axle in land cruisers behind a 2F
Are you keeping the Toyota T-case? That will more or less require that you keep the stock axle. The torque curve of that engine is far different from a gas motor. I make 400 pounds of torque, but I have to work up to it. The Cummins will just flat out twist things off if you're not carefull. It comes on all it once and at a really low RPM. Get a 14-bolt full floater for the rear. You're going to need it.
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How are your fabrication skills?
If you have some, you can always modify a 14 bolt to an offset rear, this will not only bring your width back to a normal track width, and will also allow you to bring 1 spare axle for the rear.
Or if you are going to run a dodge transfer case you have other options for narrowing the axle.
If you have some, you can always modify a 14 bolt to an offset rear, this will not only bring your width back to a normal track width, and will also allow you to bring 1 spare axle for the rear.
Or if you are going to run a dodge transfer case you have other options for narrowing the axle.
ntsqd
technerd
Ever cut and machined the tubes of a 14bff?
They're some gnarly stuff, or at least the one that I worked on was. The tubes are also tapered in wall thickness, which could make life interesting. Not suggesting to not use a 14bff, just a head's up that it's not likely to be simple.
They're some gnarly stuff, or at least the one that I worked on was. The tubes are also tapered in wall thickness, which could make life interesting. Not suggesting to not use a 14bff, just a head's up that it's not likely to be simple.
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Freds40 did a really nice writeup on offsetting a 14bolt. I am going to run a 205 so I will stick with a centered rear diff.
That combination along with the NV4500 will virtually indestructable. The NP205 still stands as the Gold Standard of production T-case strength. The ratios are not very deep, but it won't die and its much, much less money than an Atlas.
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Indestructible is pretty much what I am aiming for. I am going to bump up the power of my 6BT so I want stuff to last.
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I am going to keep the 6bt stock power. Indestructible bomb proof reliability is what I am looking for. 14bolt full floater sounds good. Any suggestions on front axle swap? I will not be keeping the yota t case. Most likely np 205
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For the front axle you might want to run a Dana 60 from a dodge. If you have a parts truck you should be all set.
You might want to do the 3200 rpm spring on the 6BT if it is a first gen motor. Stock the pump only fuels to 2500 rpm or so.
What trans did the motor originally come with? Also what year is the motor?
You might want to do the 3200 rpm spring on the 6BT if it is a first gen motor. Stock the pump only fuels to 2500 rpm or so.
What trans did the motor originally come with? Also what year is the motor?
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engine came out of a 91 2wd d250 transmission was getrag 5speed. didnt take the tranny though. I do want to keep the stock yota width. Thinking d60 front, d70 rear and d300 t case might be the way to go. Got to go to the pick n pull and look at em all and get Ideas for the drive line mods.
does anyone see problems with the d70?
does anyone see problems with the d70?
love to hear more about this build. I am thinking about doing the same swap. Alot of 6bt's under 200k for sale around here $1200 +/- a couple hundred.
That is going to get expensive, and you will get to purchase all sorts of custom axle shafts.That Dana 300 will not live behind that engine for very long.
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In order to run stock toyota width, you will need to modify the axles or run extremely backspaced wheels.
For the rear 14 bolts are cheaper to modify, and cheaper to find.
One option is you could run two short shafts which could cut your width down to 58" or 61" depending on what hubs you use.
On the transfer case the np205 would be the best best on rock solid reliability, but a np241 would also be an easy fit.
The motor had a manual which is good when it comes to turbo size, it should spool up nicely and give you some power. The autos came with a 21cm exhaust housing which takes forever to spool up. Ask me how I know.
Also is the truck intercooled?
For the rear 14 bolts are cheaper to modify, and cheaper to find.
One option is you could run two short shafts which could cut your width down to 58" or 61" depending on what hubs you use.
On the transfer case the np205 would be the best best on rock solid reliability, but a np241 would also be an easy fit.
The motor had a manual which is good when it comes to turbo size, it should spool up nicely and give you some power. The autos came with a 21cm exhaust housing which takes forever to spool up. Ask me how I know.
Also is the truck intercooled?
D300 is a good t-case if you make a couple upgrades, but it was built for a 4.0 jeep, not a torque-monster cummins. I would go np205, or np203/205 doubler if you plan on doing a lot of wheeling
ORD Doubler 4:1 Dual Transfer Case, NP205-NP203 - Fullsize 4x4 Parts
There is a couple differnet dana 60's out there, ARB has a page on their website that lists the different lockers for different axles, as well as shaft siz and spline count, I'd take a look at that and maybe print it off before you start hunting for the axle you want.
Also if you keep the toyota axles, get a ruff stuff front, 80 series outers, maybe with the new high steer knuckle kit thats being made, and some longfield's should be pretty tough...
Althoug I havent broken my front yet.
knock knock on my desk as I type that.
Also if you keep the toyota axles, get a ruff stuff front, 80 series outers, maybe with the new high steer knuckle kit thats being made, and some longfield's should be pretty tough...
Althoug I havent broken my front yet.
knock knock on my desk as I type that.
