Pirate 4x4 banner

1 - 17 of 17 Posts

·
Registered
Joined
·
8 Posts
Discussion Starter #1
Hey guys. I'm looking for opinions on choosing a rear axle for my build...
I have a 4x4 05 Tacoma - I just installed a 5.7L 3UR-FE from an 07 Tundra (not finished yet, but it's in there). It has custom-made long travel ifs with 8" Kings and I have 48" Ruff Stuff Trailing arms and 10" Kings for the rear. Currently on 37" tires - no plans to downsize. I am designing it as a desert racer but I want it to be completely off-road capable and as unbreakable as possible.
I have RCV's Ultimate CV axles in the front (lifetime guaranteed up to 42" tires) and I bought a GM 14 bolt FF rear for it already and: 6 lug hub conversion, disc brakes, shave kit, factory locker, 4:56 gear. I'm just about to the point where I am going to install this beast along with the rear suspension, but I am wondering...
Is this axle too heavy for it's own good when it comes to high-speed off-road driving? I do plan to drive over anything in my path as well and I don't want to break it. But I'm kinda worried about unsprung weight. This is my first build like this, so I'm looking for opinions and advice.
See my build on my YouTube channel (if you're a Toyota fan, you'll especially love it) Search WHIPBASH on YouTube for my channel or just search TACUNDRA to find the build.
 

·
Registered
Joined
·
5,785 Posts
The Ford 9" is the most ran rear axle in motorsports. They are very strong for their weight and size and there are so many different aftermarket parts available to build it as strong as you need it.

The 14 bolt might be the most beloved rear axle for off road use because they are cheap and plentiful, but they are big and heavy.

Do you still have the donor Tundra? Does it have the big 10.5" rear? They are drop-out style, making them easy to work on and they are basically the same size as a Dana 70.

Randy Slawson ran one in his Ultra 4 car for a couple years, says he never had an issue.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #4
I do still have the donor truck and it does have the big axle. I would have used it, but it's got a big 5 lug pattern and I really want to keep 6 lug on all 4 corners.
 

·
Registered
Joined
·
12,603 Posts
I'd say use it. Everyone says 9" is so much lighter, but I don't believe it is THAT much when you have the same tubes and outers.

Personally I prefer an over kill rear axle.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #8
I suppose I should pull the Tundra axle and weigh it for comparison. But I definitely want to keep matching lug pattern on all 4 wheels for spares.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #10
Let me get some weights on the 14 bolt parts. That might help. I really appreciate all the input by the way.
 

·
Registered
Joined
·
12,603 Posts
A sheet metal housing should be lighter. That is my thought.
Stock? Absolutely, but something that will hold up like 3.5x3/8" wall tubes and thicker 3rd area. Probably still lighter, but I don't think it will be ground breaking. Dude already has the 14b geared locked and 6 lug hubs. I'd say run it and ha e one thing you don't have to worry about.
 

·
Registered
Joined
·
12,603 Posts
Googled 14b weight out of curiosity. Looks like most people are saying a little under 400 lbs with disks. If he stays full float, I don't see the Tundra/diamond axle being much less than 350 lbs.
 

·
Premium Member
Joined
·
16,327 Posts
I'd say use it. Everyone says 9" is so much lighter, but I don't believe it is THAT much when you have the same tubes and outers.

Personally I prefer an over kill rear axle.
the other thing you are forgetting is ground clearance and pressed in tubes. adding a truss to keep the tubes in will add weight. you can run a diamond untrussed

if it was me and it was a super budget build, id redrill the stock axle and rotors and run it like that, build a truss on the back and peel out.

if you want a full float then id do the tundra center in a diamond, with 14 bolt or 60 outers.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #14
I do have to add a truss for upper links, although I'm planning to make a small one (not the whole way across wheel to wheel)
Ground clearance has been a concern the whole way through my build, so I already shaved 2" off the bottom of the 14b axle.
I didn't even think of redrilling the Tundra axle. Thats a little out out my realm. But now that you mention it, that would have probably been the best solution. And plenty strong, but then probably not much lighter either.
 

·
Registered
Joined
·
5,785 Posts
I do still have the donor truck and it does have the big axle. I would have used it, but it's got a big 5 lug pattern and I really want to keep 6 lug on all 4 corners.
Machine shop and redrill or 35 spline D70 ARB and some 35 spline promo shafts.
 

·
Premium Member
Joined
·
3,942 Posts
Tundra 3rd is 10.5" just like the 14b.
There's a hell of a lot more to the design of a diff than the ring gear OD. The pictures of Ford 9" gear sets compared to other common gear sets should drive that home.

Let me get some weights on the 14 bolt parts. That might help. I really appreciate all the input by the way.
Check the "aluminum 14b hubs" thread for assembled and individual component weights
 

·
Registered
Joined
·
12,603 Posts
There's a hell of a lot more to the design of a diff than the ring gear OD. The pictures of Ford 9" gear sets compared to other common gear sets should drive that home.
No shit, my point was that, it's not a small axle by any means. We'll, at least the center section, the tubes look weak as hell and would probably need an extensive truss to hold up.

I am just tired of everyone thinking that a drop out 3rd housing is some magical anti gravity device. I have yet to see a real weight comparison of 2 similar sized axles (this 14b and 10.5 Toyota is a perfect example) with the same tubes, outters, shafts, ect. I know the drop out housing will be lighter, but I'd bet it's only 25-35 lbs. Again, given everything else is the same. Whenever people talk about it, they act like it will be hundreds of pounds in difference.

This guy is just trying to build a reliable rig he can drive and beat on. He already has the 14b ready to go, even in the right pattern. I say run it. Maybe start pricing out what it would really take to get that Tundra axle under there and see if it's worth it. Personally, I wouldn't bother swapping it, unless it was in a diamond or Ruff stuff housing.

Don't get me wrong, I love drop out 3rds for many reasons. But I also love bang for my buck. I'm not going to spend a few thousand dollars to save 35 lbs.
 
1 - 17 of 17 Posts
Top