Time to swap out the 40 axles (1 Viewer)

[reddingcruiser]

Well, I couldn't pass up the deal and this takes care of my full-float rear axle craving.

I am also upgrading the front axle with the FJ80 birfs and Hell Fire knuckles and high steer from Ruff Stuff. I've done enough reading today on 'mud to know there's no way I'm putting the FJ80 front axle housing and teenie ring gear up front. I have some more research to do, but I am pretty sure the FJ80 knuckles are going to end up on my existing 40 axle and ARB.

I'm going to tackle the rear first since it's the simplest, though I need to figure out what locker I'll be putting in place of my existing Detroit. I pretty sure it's not going to work with the FF axle.

Well, there lots of brackets to carve off the rear axle before it goes in and that will give me something to do next weekend. I am pretty sure Toyota intended to cover every square inch of the housing with brackets.

 

[DSRTRDR]

 

[74fj40]

Looks awesome. What’s your plan for the front housing to match the width of the rear fzj80 axle?

 

[reddingcruiser]

Looks awesome. What’s your plan for the front housing to match the width of the rear fzj80 axle?

That's the good part. I was always planning to get 63" axle width and built the front axle with that in mind. It's actually an FJ60 housing with a 4Plus extender sleeve.

 

[74fj40]

Nice! I run the same setup. I think you’ll like it!

 

[reddingcruiser]

Nice! I run the same setup. I think you’ll like it!

You have the 80 knuckles on an FJ40/60 housing?

 

[74fj40]

Oops sorry, I only have 60 knuckles, but I run the extension sleeve on a 60 housing and an fzj80 rear.

 

[reddingcruiser]

Oops sorry, I only have 60 knuckles, but I run the extension sleeve on a 60 housing and an fzj80 rear.

Darn, well I'm sure getting the 80 parts on the front axle will be pretty straight forward.

I like the bigger birfs and the caliper setup (banjo fittings) and vented rotors. My current disk brake rotors are not vented.

 

[74fj40]

Did you already build the front 60 housing?What you might consider doing is taking your old rear fj40 axle, cutting the flanges off, and using the fzj80 front claws in it. I think it would yield you a lot more width. Especially if you use an extension on the short side.

 

[reddingcruiser]

I already have the extended 60 housing. My rough math says the finished width should be just about right

 

[Cruiserdrew]

Have you considered a custom front housing?

You could get any width you want, use the external bits from the 80 axle and have a really sweet full width set up with bigger birfields.

My vote would be: 80 axle in the rear as is. Custom front axle with RuffStuff or Diamond axle at the width you want. Then 80 knuckles, birfs brakes etc up front.

 

[reddingcruiser]

Yeah, I'm considering the custom option and was going to call the Ruff Stuff boys next week. I'm afraid the sticker shock will more painful than I care to tolerate.

 

[47coeman]

I went with the Rough Stuff axel’s front and rear, ya the sticker shock did happen but now that it is over I am glad I did it. Went 60 width for the both. All I can say is they are top drawer in quality, I am a happy boy.

 

[Rock40]

Maybe a dumb question but will 80 knuckles and birfields fit on a 40 housing? I was under the impression that the knuckles and birfs are quite a bit bigger. Cool swap, I have a FF 80 rear in my 40 and it's held up very well for years now with an ARB, stock shafts and 37's

 

[reddingcruiser]

Maybe a dumb question but will 80 knuckles and birfields fit on a 40 housing? I was under the impression that the knuckles and birfs are quite a bit bigger. Cool swap, I have a FF 80 rear in my 40 and it's held up very well for years now with an ARB, stock shafts and 37's

After a quick check last night of the O/D on the front axle housing on 40 and 80, it looks like they are pretty darn close. Right now the 80 axle has a lot of crud on it, so an exact measurement wasn't possible. After I get some of the brackets off and get a clean surface I'll know for sure if the extended 60 axle it will work. I'll talk to Ruff Stuff next week and make a final decision. After all, Rubithon is only a little more than 5 months away.

 

[RustyNailJustin]

Other than the housing, I built a very similar to what you want to do.
I am looking forward to your build.

 

[reddingcruiser]

Other than the housing, I built a very similar to what you want to do.
I am looking forward to your build.
View attachment 1616451

Who built your axle housing?

 

[RustyNailJustin]

Diamond axle. Even though it's a 9.5 3rd. The center section is smaller making it way easier to mount leaf springs on the diff side.

 

[White Stripe]

AFAIK u can use the 80 axle knuckle balls in a 60 or 40 housing but need to machine down where it slides into the housing slightly on a lathe, not really a big deal. Then u need to use aftermarket 80 steering where everything is up front such as from slee. I looked into doing this but it was too much money for me at the time.

 

[cruisermatt]

I'm going to tackle the rear first since it's the simplest, though I need to figure out what locker I'll be putting in place of my existing Detroit. I pretty sure it's not going to work with the FF axle.

Why wouldn't your Detroit work in the 80 axle? Just swap the whole third member. A carrier-replacement locker like a Detroit or ARB from a 40/60 won't work in an 80 third member because of the different carrier bearings, but the entire 40 third will work.