[Edited] I f***ed my birfield by it to set the axlehammering past the oil seal, screwed it up.

[kevin in okinawa]

Ok update as I try to figure out where I was getting hung up on both sides as I had the knuckle installed on the left and right as is instructed by the FSM and any install guide before I inserted the axle. Talked to my local cruiser mechanic who did the diff regearing and relashing and he told me that if you lock down the knuckle housing to torque specifications before you insert the axle/birf, there are times when the knuckle top and bottom plates come into contact with the birf/axle, keeping everything from inserting or coming out smoothly. You should be able to avoid this by having the birf rotated with flat side up but he said sometimes just releasing tension on the knuckle top and bottom is enough to provide the 1-2 mm of clearance that allows a birf/axles to seat in all the way and that my pounding may have just force it past this obstruction. Interesting theory. Also, don't do drugs kid and don't use a hand sledge to figure this problem out.

Whoever told you that, listen to that guy. I forgot I tried that trick too. He knows what he’s talking about.

To answer your other question, yes, continue to slowly rotate the diff flange and place pressure on the birf/axle until you feel it give you that glorious last 3/4”! It really helps have someone else do the turning so you can “push hard” on that birf. Especially the long side.

 

[too tall]

Ok update as I try to figure out where I was getting hung up on both sides as I had the knuckle installed on the left and right as is instructed by the FSM and any install guide before I inserted the axle. Talked to my local cruiser mechanic who did the diff regearing and relashing and he told me that if you lock down the knuckle housing to torque specifications before you insert the axle/birf, there are times when the knuckle top and bottom plates come into contact with the birf/axle, keeping everything from inserting or coming out smoothly. You should be able to avoid this by having the birf rotated with flat side up but he said sometimes just releasing tension on the knuckle top and bottom is enough to provide the 1-2 mm of clearance that allows a birf/axles to seat in all the way and that my pounding may have just force it past this obstruction. Interesting theory. Also, don't do drugs kid and don't use a hand sledge to figure this problem out.

There is no way the trunion pins can come into contact with the birfield when they are tightened down and the flat spots are lined up properly. You assume your housing is not bent because both sides were equally hard to get installed. Maybe Both sides are bent? I have lots of stock shafts I'd be happy to send you for free. Pm me your address and I'll get a shipping quote. Its pretty easy to tell if your housing is bent. Stand back about ten feet and zoom your camera in until it is past say the 50mm conventional lens focal length and take some pics. Anything wider than that will have aspherical distortion and make it hard to tell from a visual standpoint.
in my area , most Toyotas have been off roaded a lot by now and I would say that more than 50% of the ones I look at are bent. I usually straighten them out before trussing them and rebuilding them. Look closely at the tube beneath the perches, that is the spot where they all bend. Generally if you are having a very hard time installing your shafts - you have a bent diff.

 

[taoofbean]

ntact with the birfield when they are tightened

There is no way the trunion pins can come into contact with the birfield when they are tightened down and the flat spots are lined up properly. You assume your housing is not bent because both sides were equally hard to get installed. Maybe Both sides are bent? I have lots of stock shafts I'd be happy to send you for free. Pm me your address and I'll get a shipping quote. Its pretty easy to tell if your housing is bent. Stand back about ten feet and zoom your camera in until it is past say the 50mm conventional lens focal length and take some pics. Anything wider than that will have aspherical distortion and make it hard to tell from a visual standpoint.
in my area , most Toyotas have been off roaded a lot by now and I would say that more than 50% of the ones I look at are bent. I usually straighten them out before trussing them and rebuilding them. Look closely at the tube beneath the perches, that is the spot where they all bend. Generally if you are having a very hard time installing your shafts - you have a bent diff.

Agreed. I don't get the trunion pinions were the obstruction part of this story because they should have stopped or impeded the birf/shaft from coming out correctly but instead both shafts slid out like butter. Your idea about the housing being bent on both sides is compelling. I will take a pic. of both sides to see about flat.

You know, besides regearing and airlocking the diff so that could have shifted the diff placement in that last 3/4 inch. But in addition to that I retorqued the crap out of my Ubolts holding the suspension to the frame up to spec. Originally when I put the suspension on I just apparently drove the Ubolts on with an impact gun but never torqued them. I wonder if I bent the housing out of the alignment it was in on both side just in that process of torquing the crap out of the Ubolts.

Just grabbing at straws here because it makes so little sense, if you slide the axles in from both sides and engage the diff from both sides, the only obstructions that could/should be in the way are the housing/bent axle, maybe the trunion pins (thus why you rotate it to flats) and the seal (which I have been told repeatedly is not a barrier to entry), and the diff gearing on the other side which should not be an issue because you are already engaged.

Here is a shot clean through the cleaned out housing interior before I reinstalled the diff and then the axles. No obvious major distortion at that moment.

 

[Mark W]

Mark, I hear you. This is my first rebuild and I am taking my time and trying to learn along the way.

If the axle stops in the last 2cm on both sides, and it is not the seal that could be obstructing it because as you said, that is not a thing, can you help me out with what it could be? I did not just pull both axles once I got to this point and fish them back in multiple times because at least on the long end, it was a pain in the ass to find the diff and get it to smoothly align like butter and slide into place into the diff. I didn't want to do that part again multiple times. The seal was the only thing I can think of as point of friction on both sides but I am completely open to whatever it could be. As part of this rebuild I dropped the third member and had it regeared and an ARB air locker placed inside. I had already installed and locked that new third member down before this attempt at finishing the knuckle rebuild. So this is effectively a new diff at the center of these axles. I wish I could peer inside the diff while it was installed without a scope to make sure things are not munged from that point of view.

Just getting back to the computer here.

2cm is almost an inch. At what point did you detect this... for lack of a better term, "failure to insert"? Where were you in the installation process, what told you that the axle was not in far enough and how did you determine the amount? Was the birf itself jammed up at all, or was it moving freely in the knuckle? Was it still trapped between the trunions at that point?

Torquing the knuckles and tightening the Ubolts will not have any effect on this.

Mark...

 

[g-man]

I think the weight of the longer inner axle makes it tend to hit the diff lower than the center. So, you have to raise it by levering it. Push downward on the birf outer end while being careful not to deform the new outer axle housing seal (the thing you will be levering on). There is just no way to lift the heavy end of the inner axle once it's inside the housing. NO way would I ever hit it with a hammer. Turning, while pushing downward on it slightly. Think of levering the axle like a see-saw.

 

[Skreddy]

Are you sure the axle seals were seated all the way? Maybe you were essentially using the axle to seat them?

 

[kevin in okinawa]

So to recap, everything is back together, right? You are just flummoxed as to why it was so difficult to get that last inch? If it went back together and works, don't worry about the "why" of it. Axles are just royal pains in the a$$ sometimes, and especially on the long side.

 

[RevISK]

I skipped through all of that just come here and say, “BFH’s have their place, and it’s not always”.

Cautionary tale for someone down the road hopefully.