2003 SAS 1UZ

[Kevin82]

Thanks Scuba Tacos

Small update.
I got the airbag mounts placed and welded, im just gonna add a couple gussets. I originally tacked them centered over the axle but I ended up moving them back 1” because of possible interference with the airbag/cradle to the fuel tank mount.
I built new bump cans because the ones i prefabbed just werent gonna work. Also i decided having big cut outs in the cans isnt a good idea for a daily driver in the PNW, especially if i plan to change the bumpstop heights every time i put the snow wheeling tires on. Im gonna build some caps for the top to keep mud/water/salt out.
I originally centered the rear tire in the wheel well at full stuff but i may end up moving it back 1” to match the airbag placement because i would prefer them centered and also when its time to cut the fenders out i want to keep the fuel door area intact. Not sure if i will be cutting that much out of the fenders but i would like to have that option. I dont want to move the spring hangers so if i choose the move the axle back i will just drill the spring perch ahead 1”. The axle will be getting 1.5” wider per side with the full float kit and IFS hubs so i dont think i will have any tire to can clearance issues. The bump cans was just tacked for the sake of taking pics, they will get boxed in
I checked a stock driveshaft for length and it seems i can run it as is, or 1” further back, either way will work. I will probably be running a thicker wall shaft but i want the option of throwing a stock shaft in if it should break outta town

[Aisin]

Originally Posted by Kevin82

Theres a few full float toyota rear axles out there, in my experience and from what ive read, they use the same thickness as any other toyota axle, around 3/16”. I dont think the 60 series full float is much bigger dimensionally but i could be wrong. Im gonna be adding a gusset on the backside that the runs from the diff cover all the way to the ends, so that will add some strength but time will tell if there are any issues i suppose

My full float FZJ80 bare housing is over 80 pounds. It is definitely beefier than a semi float housing.

[Kevin82]

Working on getting the motor/trans mounts done. I hate the big notch that people do on the passenger side frame rail for the draglink/panhard so im planning to cut a section of frame and raise it an inch or two. Im gonna plate the outside of the frame anyways so its not much more work to plate the inside and i will incorporate the steering box mount on the drivers side too.
Im not sure how much and exactly where the cut and raise will be so i left the inside plates long for now so that i can get my motor mounts done and keep progressing with mock up. The inside plates are just tacked for now because they will be coming off again.
Its a 2 piece oil pan, the bottom of the aluminum pan is sitting flush with the bottom of the frame. Im gonna have to notch the lower steel pan. Currently the aluminum oil pan is sitting on 2x10 and the t cases are held up by a ratchet strap through the shifter hole. I was using the hoist from the side because its cold outside haha.





post images

[NorCalPR]

Fwiw I ran a full float kit on my last rig. It was on a tacoma elock housing.

The housing was not bent, and after years of running it I wore away the outer splines. I found that on jackstands the axle was straight. Under its own weight the housing deflected enough to wear away the splines. My theory is the stock housing is fine for a semi float since the load is spread between the carrier bearing and the end (and the error in striaghtness can be larger) In a full float, all the weight is at the ends, so a lot of load is between the perch and the end.

If its a 8.4 housing you may be ok, but if its an elock housing it wont hold up. I gusseted the top of the housing from perch to perch, and sleeved the outside of the tube between the perch and the end with some schedule 40 pipe. I ran it like this for a year or so and sold the truck. But gusseted like this the housing did not deflect.

It also helps to pretension the housing before welding the truss. Keep it tensioned while welding and release it when its cool. I did restraighten the ends after welding but it didnt move much.


Build is looking good, keep up the solid work!

[IMG][/IMG]

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[Kevin82]

My incentive for doing the full float is more so the ease of servicing and so i can get home if i break a diff or shaft. It also conveniently widens my rear axle to 63.5ish WMS so i dont have run wheel spacers either. When i had the to do the rear wheel bearings on my current daily driver taco i didnt have a shop space to do the press work and i had to rely on a shop to do it. Of course it was on a long weekend and no one was open, it was a major pain in the ass and i vowed to do full float on my build.

Thanks for the detailed reply NorCal, what do you mean by an 8.4 housing holding holding up but an Elocker not though?

My truss runs all the way and will be welded to the flange inserts on the ends. I may add a brace on the front side of axle too since deflection seems to be such an issue. I plan on picking up an aligning bar for checking the axles so i can check it on the truck with it loaded too. I can always switch to a beefier housing down the road, hopefully before it wrecks my shafts. The new TG 8.4 housings look pretty good, might be in my future but not really in the budget and i figure i can make this work.

[NorCalPR]

Here's a good shot from my build of the elock housing ends. They neck down just before welding to the end. You can see thr piece that I welded in there to beef it up



You can also kinda see it here too. This was when I tensioned the housing to weld it



I did not check alignment with an alignment bar. Instead I used a laser. You can check the straightness by assembling the hubs onto the axle, and place thr jack stands on the end where the hubs are (on the hubs, not onto the housing) Place the laser (i just used one of those magnetic ones that shine a dot) on the brake rotor and shine the laser at something far away. I used the wall 20' away.

Spin the housing 360 degrees. If the laser moves, its bent.

I was able to get the housing straight enough that the laser moved maybe 1/16 or less" over a 20' distance.

Just an idea if you cant source an alignment bar. I'm confident its damn close since before I could never assemble the hubs onto the wheel hubs without a hammer but I could easily get them into place loaded or unloaded.

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[Kevin82]

Thats a good trick to know with the laser 👍 The 8.4 housing narrows just the same. Heres a few shots of the truss i made awhile back. I need to cut the perches to get the truss sitting in place, but it gives you the idea.







I decided to go with radius arms because 3 link would be a ridiculously tight squeeze (IDK if possible) with exhaust/links/tcase clearance and with radius arms essentially having a built in sway bar i dont mind losing a bit of crawl ability for better high speed manners. The original plan was to actually use the FJ80 radius arms flipped to the topside of the axle but i quickly realized it wasn't gonna work for the up travel i wanted and they are far rom ideal anyways so i settled on building jeep style radius arms where the uppers are canted in towards the middle
I spent a bit of time mocking things up and humming and hawing tonight. Threw the headers on, the dana 300 mount and placed axle at full bumpish. Exhaust to upper radius arm link is gonna be tight but it looks doable. Since im planning to disconnect one upper radius link when crawling im gonna shoot for the general rule of 1/4 of tire size for link separation. More separation will give me more of a sway bar effect and better high speed manners and then i can down tune it by using a spring loaded upper radius link if i wanted. One nice thing about a radius arm vs 3 link setup is i dont need strictly vertical separation on the uppers/lowers. Horizontal separation counts too, so i dont have to go so high with the uppers.











The axle is sitting at 6” up from a ride height of 24” frame height on 37s so my goal of 5” uptravel is looking very possible
I put some 1.5 DOM in there to give me an idea of how the panhard will look

[NorCalPR]

Yea, I'd sleeve over that for sure, even with the truss. That spot is a huge weak spot on these axles. Iirc its 3" sch 40 pipe that fits over it perfectly when its sliced in half.

Plus if you need to pull the ends straight, its easy to hide the weld nuggets in that neck down spot that you add to shrink

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