80 diff in 40 axle (1 Viewer)

[MADDEN72]

I have a Suzuki based rock buggy with fj40 axles Under it. The rear has 5.29's and a 12 bolt mini spool and I've broken a few short side shafts so I decided to put some cromo's in. I knew poly performance made shafts for cruisers but haven't looked at them in awhile And it looks like they are discontinued.
I happen to have a semi float fj80 rear axle sitting around and it looks like the extra length on the short side might solve my problem, also having 3" wheel spacers on the rear now, it would be just about the right width. My question is. Will my third member out of my 40 series work in the fj80 housing?

 

[Cruiserdrew]

Yes, direct bolt up.

But why not a different axle you won't break like a 14 bolt?

 

[MADDEN72]

Yes, direct bolt up.

But why not a different axle you won't break like a 14 bolt?

Thanks for the reply, that's what I thought but wanted to make sure before I started tearing into it.
The reason I'd be using the 80 is that I have this axle sitting here, I already have the investment in gears, spool, disk brakes and custom driveline so the only expense would be some brackets and a little time. Also, my rig weighs around 2700# wet and I've wheel really hard on those 40 axles with 39 stickies for years without a single problem when I had a lockrite in the rear and have only broke a few shaft in the last six years with the spool, so I'm confident that with a shaft that's long enough to twist a little when bound that it won't break again. I could also always go back to a lockrite. AN arb would be the best thing but I'd go to a D60 before I made that much of an investment.

 

[cruiseroutfit]

3rds are a direct swap assuming you didn't end up with some old course spline shaft axles.

 

[MADDEN72]

3rds are a direct swap assuming you didn't end up with some old course spline shaft axles.

Cool, shafts are fine splined

 

[cruiseroutfit]

Cool, shafts are fine splined

You sir are golden. You might check with @justdifferentials, I recall they had chatted about doing chromo rear SF axles. We still get regular calls for them... it's be great to have an option. I'm rocking the Nitro chromo FF shafts in one of my project rigs, I'd love offer a SF too!

 

[MADDEN72]

I did find someone making just the short side cromo shaft for the 40 which makes sense, I'd have to do a search again to find it. At that time I'd already started looking at the 80 axle though. It would be very cool to find some cromo SF 80's, that would solve my problems for sure.

 

[MADDEN72]

Here's the short side only shaft I found for the 40 series SF. In anyone is interested.
Nitro Gear & Axle, AXT35110 - Toyota 9.5in FJ40 & FJ60 Land Cruiser LC 30 Spl Semi Float Short Side Nitro Rear 4340 Axle Shaft

 

[Bripars40]

I've got a 14 bolt narrowed to fit under a 40 that is for sale. Pm if you're interested.

 

[MADDEN72]

I've got a 14 bolt narrowed to fit under a 40 that is for sale. Pm if you're interested.

Thanks, a 14 bolt would be the ultimate for sure but I thinks it's overkill for my application. I think a weaker axle will hold up fine to my anemic hp and light weight. I think the trade off for ground clearance just wouldn't be worth it.