J80 vs J100 spider gears interchangeable?

[Phant0maz]

Good evening

I have a j100 rear axle which I want to convert to a full floater.
The axle shafts of j100 are 32 splines 34mm in diameter. I need to convert the diff somehow to fit 30spline shafts. Are the spider gears of j100 and j80 /or other 30splne diffs/ same size and shape besides the splines count? And I’m talking about the factory locker differential.

 

[hoser]

Yes, I believe the spider gears are interchangeable. But note, the J100 axle is wider than the J80 axle by about 5 inches.... and therefore the axle shafts are longer too.

 

[Phant0maz]

Yes, I believe the spider gears are interchangeable. But note, the J100 axle is wider than the J80 axle by about 5 inches.... and therefore the axle shafts are longer too.

That is the point, I need to shorten it. I got the j100 axle for a project which I didn’t complete. Now I need a diff for 30 spline shafts and most likely I will use j70 FF shafts it the spider gears 100/80 are interchangeable.

 

[hoser]

Can you clarify? So, in the end, you want the equivalent of a 70 series full floating axle?

 

[Phant0maz]

Can you clarify? So, in the end, you want the equivalent of a 70 series full floating axle?

I have front 70 axle and rear 100. The easiest way to match them by width is to shorten the rear one. I know it might sound strange but here the prices of the axles are insane. Not to mention that finding a full floater is almost impossible.

 

[hoser]

I had a pair of FF 70 series axles I sold awhile ago. LHD from Europe even! Could've sent it back your way!

 

[Phant0maz]

I had a pair of FF 70 series ...

Thanks for that. I like assembling stuff from spare parts which lay unused in the backyard.