Topic: Toyota front axle questions

[tawneybuilt]

Does any one know how long fj80 inner axles are compared to pickup  inners?
What is the inner spline count for an fj80 birfield - would it fit on the end of a pickup inner axle or pu birf on 80 inner?
Would a 30 spline longfield fit a 80 inner?
How wide is a 4x Tacoma rear axle?
I think I have an    for a trick front axle but I might be 
thanks

[b_ripper8]

80 Axles are wider and the knuckles are huge compared to mini-truck axles. I'm not sure about the spline count on the birf's and axles. Those 80 axles are awesome though, after rebuilding my brother's wife's 80 front, I want one bad! 

[tawneybuilt [OP]]

When I built my 71 fj40 I did a spring over and shackle revears on the stock front housing which meant the caster angle had to be corrected after the pinion angle was set. At the same time I converted the front knuckles/brakes to SA pick up disk and threw away the stock drums. In order to perform the caster correction the knuckle mounts have to be cut from the housing and rotated. Also, in order to perform the brake swap, the fj40 knuckle mounts have to be modified slightly to fit the pick up birfs. Because I bought a complete pick up front axle to rob parts from, I decided to cut    the knuckle mounts off both housings and transplant the pick up mounts onto the 40 housing. It was far less work then I thought it would be and it works flawlessly.
This is nothing new or original but Ive been thinking lately of similar transplant on a fj80 housing. OTT wants $800 for fj80 high steer arms and knuckle mod and you still don't have selectable hubs. Would it be possible have the advantage of a high pinion and extra width combined width much less expensive high steer arms, less expensive longfeilds, and retain the selectable hubs?
, if the knuckle mounts are being cut off the 80 housing then lets take it a step futher and just flip the whole housing to a drivers side
drop for a Tacoma. Modify the housing slightly to get the third to fit right side up in an up side down housing, I think the bolt pattern is a mirror image of itself so just a little grinding to get the ring gear to fit. Then put a drain plug on the top (now the bottom) of the housing and vvvwwaaa la! trick Taco front using mostly Toyota parts!
Would this work or should I have stopped thinking a while back?      

[b_ripper8]

I kinda see what you're saying but it seems like more effort than it's worth. I've also cut and rotated my knuckles which isn't that big of a deal but now you want to make it a driver's side drop for a taco. This seems like a good idea for the taco's running the 3.4L but for the 2.7L owners (me) I would rather stick a W56 with twin cases behind my engine with a driver's side drop. Then you can just use the 80 front as it is and use a T-100 rear for the width. As for putting an 80 front upsidedown, you wouldn't have a high-pinion anymore and you're gears would be running in reverse which I'm pretty sure would be a problem at mid to high speeds. Good thoughts though, I like how you're thinking outside the box. 

[tawneybuilt [OP]]

I don't own a Tacoma but I'm starting to like the idea of building one as it would be way more drivable than my 40 which I don't own a top for and doesn't have ac or heater or wipers or radio or...
If the third member was turned upside down then the housing turned upside down then the third would right side up again and turning
in the correct direction. 
Or one could take a prerunner Taco and run a divorced tcase to either a drivers or pass side drop front axle 
I'm still curiouse if a pickup birf would fit on a 80 inner axle?   

[To The Floor]

Willy mammoth did this mod for one of his rigs.  i forgot what it was but it had the opposite side transfer case input flange, and he flipped a Toyota 8" mini axle upside down and did the appropriate modifications to do it this way.  Of course if you want to spend the money you can have diamond axles make a housing that has the diff offset to the other side and then use your third member and knuckles and everything.  That would be the route that I'd take to do a Taco front axle because I wouldn't want to run Dana.  Then diamond axles will also make any width axle you want and make custom axle shafts for it as well.  So in all reality you could have them make you axles to run a full width Toyota 8" on a Tacoma without running FW Dana axles. 

[Northern Runner]

I am not sure if they are available in the US. But in Canada I used a front axle from a landcruiser HJ75. These trucks were built by Toyota Commercial Division for off road use only. They use them for mining and logging industries.  They are extremely heavy duty, and a mini-truck high steer will bolt on as well. The front diff is stock hy-pinion, with 30 spline axle shafts, the birfields are the same size as an 80 series. You have to inboard your front springs about 1" from stock to use the diff. And if you can get a rear one as well, they were full floaters with factory disc brakes. They made these trucks from 71-81 then came out with a newer series (i cannot remember the new number for it) but it uses the same axles. I then used my factory IFS caalipers and hubs, redrilled the LC rotors to bolt to the hubs, mounted the calipers outboard, and the width is the same as a V6 rear.

[tawneybuilt [OP]]

I dig the Diamond Axle housings but from a cost effective view it seems that the price of a compleat fj80 front axle would be just a little more than the high pinion third itself.
Once again the Canucks get the goods. I would be hard pressed to find a HJ75 in Cali and it sounds like it still isn't the same width and a Taco rear.
Anyone know what the inner-to-birf spline count is on a FJ80?

[b_ripper8]

They didn't release any HJ's in the US that I'm aware of, I'm sure a few have been imported. Sounds like the perfect axles though. As for Mini-truck birf's in an 80 housing, the knuckles are too big and the trunion bearings wouldn't do their job. The 80 birfs are bigger and so are the knuckles. As so the spline count, I can't remember sorry.