FJ40 Full Floater Axle Build (IH8C-CLIPS)

[Skrewball]

Well...now you know why it was so easy to break those axles....

Cam has the trail gear studless hubs in hand and said they are impressive. He is getting a Roughstuff housing, and has a 60 housing now.

Before i replaced my mini truck housings with trussed versions they had warped real bad do to stress and lack of truss. I was breaking rear shafts way too easy. now that its straight, no more broken shafts(i guess the cro-moly had something to do with it as well..)

 

[Stumpalama]

Take note of my observation of needing a 3/16" spacer to suck up the drive slug movement... Seems I need to collude with Cam.

Well...now you know why it was so easy to break those axles....

Cam has the trail gear studless hubs in hand and said they are impressive. He is getting a Roughstuff housing, and has a 60 housing now.

Before i replaced my mini truck housings with trussed versions they had warped real bad do to stress and lack of truss. I was breaking rear shafts way too easy. now that its straight, no more broken shafts(i guess the cro-moly had something to do with it as well..)

 

[Skrewball]

**Edit: I didn't read enough before posting.. i'll re-edit with something helpful......if i can..ha! **

Instead of a spacer, maybe put 2 3/8-16 set screws with red loctite into the drive slug and keep them out enough to take up the slack in the slug to cover area. shouldn't be much force there.

are the end of the axles going to have the M8 tapped hole like a front birf? if so, you could just use a longer bolt and space it out enough to take up some of the gap between the slug and cap. You definitely don't want it tight to the cap though. a little slack is a good thing.

 

[Stumpalama]

The thing with the TG setup is that the cap is part of the slug retention system, using the spring clip to retain the slug and the cap. I would worry that allowing the axle and slug to move in and out would cause a hammer effect and eventually hit hard enough to knock the cap off.
I am admittedly ignorant to the Dana drive slug setup and I don't know how much lateral force is generated. I just see that the kits designed for rear axles have a spacer, though they also use an inner clip to retain the slug and the cap screws to the drive slug.

 

[Skrewball]

how far down into the hub can the slug slide?

To ease your mind with axle retention/strength of clips, go to Strites house and pull one of his rear hubs out. He has an old school warn conversion. While i'm sure he doesn't push it as hard as you will, it will at least give you a proven example of what works on a full float 40 with a similar setup.

 

[fountainhead]

We warped this rear 80 housing pretty bad when building the truss for it but were able to straighten it on a welding table at the house:

It curved up on the long side, and we had to get it cherry red to get it to move. One tip - once we got it strapped to the table and leveraged for the correction, we put a laser pointer in the end of the spindle and marked an X on the wall. As we heated the housing, the laser pointer in relation to the X made sure we were moving along the correct path. (We didn't have the straight bar or alignment pucks, unfortunately).

You can fix it...

 

[Stumpalama]

Fortunately, I have the alignment bar and jigs that will help ensure I get the axle just right.
I'm going to measure the axle from the ground to identify exactly where the bend begins, but I suspect it is where @J Mack stated.

 

[Stumpalama]

I'm tempted to truss it from the rear, but I'd kind of hate to give up the access from the rear cover.

 

[Stumpalama]

How about of I cut down a piece of 1/4" 2x2 and used it as a truss for the underside of the axle? I wonder if welding it on would straighten the housing while also strengthening it and helping to prevent it from bending again. I know I loose some clearance, but I can't think of another way to do it without either permanently fastening the diff cover or fabricating an overly complicated detachable truss.

 

[LAMBCRUSHER]

you mean much like the fj80 axle is gusseted? Yeah, why not, but try not to overcorrect, then...

 

[peteinjp]

Hmmmm I think I'll throw a level on the rear full floater WMS and check right to left.... It's a 70 series unit that I re-welded perches at 40's width.

Hi-jack over. Can't wait to see how you straighten it. I've got just the beam you need.... But it's in Japan.

Pete

 

[Stumpalama]

What size chain did you use? I have 3/8" chain, but think I will need 1/2" grade 70+ chain to ensure a safe setup.

No big deal to straighten, looking at the picture it looks like it warped when the spring perches were welded but it’s hard to see everything from pictures. Put a straight edge to see where it’s bent then chain and push on either side of the bend.



My housing did the same thing right at the perch and in this picture you can see what I’m talking about with the chain and porta-power.

More detailed description here: Target carrier

 

[J Mack]

What size chain did you use? I have 3/8" chain, but think I will need 1/2" grade 70+ chain to ensure a safe setup.

The chain I used was grade 80 3/8” lifting chain with a working load limit of 7100 LBS, I wrapped it around twice and crossed my fingers!!!

Honestly I used a ten ton porta- power with a gauge and never pushed it past the 7100 LBS working limit of the chain I used.

 

[Fast Eddy]

Great. I had a seal go bad in my narrowed 80-series axle, on the long side. I never worried that we might have warped it before reading this thread, but it would make a lot of sense. We welded the perches and an anti-wrap bar on that side. It has the factory gusset on the bottom, though. We'll see how long the new seal lasts.

The seal would only leak in one orientation. If I rotated the drippy oil "up", it would stop leaking. This seems to say something about the axle shaft. (?)

 

[LAMBCRUSHER]

I guess I got lucky, my axle doesn't leak or show signs of misalignment. Prolly due to the limits of my welder...I did take it slow and wrapped the whole thing in gloves, my apron and a blanket overnight...but it was also very cold outside...part of me never wants to know...Post pics of the process, Stumpy...

 

[Stumpalama]

I guess I got lucky, my axle doesn't leak or show signs of misalignment. Prolly due to the limits of my welder...I did take it slow and wrapped the whole thing in gloves, my apron and a blanket overnight...but it was also very cold outside...part of me never wants to know...Post pics of the process, Stumpy...

Oh, I will document it all. I am breaking new ground as far as my fab/repair experience goes.
Out of curiosity, I called around to see what it would cost to have a shop straighten the axle, and I learned no one in the area does it.
I'm debating the investment in a 20T HF press to help with this... it has the added bonus of easing the R&R of the wheel studs.

 

[jstncse]

I don't think you need a press to straighten the axle but "use whatever it takes to justify cool new tools"

 

[peteinjp]

This all makes me wonder how the factory welds on trusses etc without a lick of warpage. I've clamped stuff down and welded it- waited for it to cool well and it still moves albeit probably less than if it had not been fixed to the table.

I was thinking of trussing my axle cut now I'm wary of doing so.

Pete

 

[Stumpalama]

I don't think you need a press to straighten the axle but "use whatever it takes to justify cool new tools"

You think just heat or welding a lower truss on the axle would be enough?

 

[jstncse]

I think you will need to use a porta power to control the tweaking. I was referring to the 20ton HF press in the previous post.
I would chain it like you have talked about and bend it back to straight then weld a plate on your antiwrap bracket to keep it from going back where it is now. Providing that the antiwrap bracket was what caused it in the first place.