HZJ73 vs BJ73/BJ74 axle differences

[theferg]

I've found some threads stating some differences between the HZJ73 (1990-1997 70 series) and BJ73/BJ74 front axles and just wanted some clarification on them.

It appears that the front axle went to the 8" high pinion diff, a slightly larger knuckle, and a slightly larger birf.

Is everything else the same between the front axles? Specifically, the inner shafts? And obviously knuckle kit stuff like felt rings will be different due to the knuckle size, but how about the bearings and seals?

Thanks!

 

[Hulsty]

I think most things are difference aside from the wheel bearings and maybe the king pin bearings. inner shaft are different and I think the seal is larger too, calipers are different, sway bar, hubs are different but interchangeable, free wheeling hub seals interchange and probably the rear hub seal too

 

[Tapage]

didn't all 7* series axles share the same width ..?

 

[cruiseroutfit]

didn't all 7* series axles share the same width ..?

That is the dilemma theferg and I are trying to solve. We know the 40/55 and 70 (up to 1990), what we do not know is if they are the same for the 1991+. Toyota shows different numbers but obviously that isn't always a direct clue and they could still be the same. The gents from Just Differentials think they 'might' be the same as the LJ70 (light-duty LC's) of the same era but can't confirm 100%. We don't have one here to measure so I've asked the customer to measure.

PS, Hope all is well my friend!

 

[Hulsty]

Yup same total width

 

[cruiseroutfit]

Yup same total width

So have you or someone you know fitted a set of inners/birfs from a pre-90 into a 1990+? Customer is looking to upgrade to a chromoly set, the birf is a bit smaller (though stronger) than the mid-size 90+ 70 birf but we just need to confirm axle lengths are 40/55/70 vs RJ70

 

[cruiserdan]

Jeff Zepp had a mine truck with a top-pinion front diff. He broke that at CM a few years ago and he may remeber what they fixed it with. I just gave Bryce Jeff's number.

 

[rick_d]

axle shafts are different length for high pinion fronts
40/60/70 short side same 1981-1990+
mini/60 long side same 1981-1990
I have not looked, but I am not sure high pinion 1990-1998 are same after the big birfield and coil change 1998-2006.

2007-present short and long side are longer still, but shorter than 80 series minimally.

 

[Tapage]

I'm clear that might be a difference between pre 90 7* series and post 90 7* series .. but among those groups must be the same ..

Another question is, are the post 90 7* series inners 30 splines or 24 splines like 80 are .?