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Strengh differences between 40 and 60 series

Posted: Wed Apr 19, 2006 5:12 pm
by Bighazza
Hey everybody

I have a set of 40 series axles sitting under my other Fj40 (1975) and thinking of using them in an up coming project.

My question is, are there any differences in the strengh between the 2. I know the 60's are wider but that doesnt bother me for this project ;)

They would be under the power of a V8 and around 35-37" tyres

CHeers guys! :D

Posted: Wed Apr 19, 2006 9:28 pm
by bad_religion_au
a 75 will probably have course spline cv's and might have a semi floating rear

if that's the case, yeah their heaps weaker

you can throw the fine spline CV's and freewheeling hubs in them (from late 40's, 60's, 75's and early hilux's) and that'll make them just as strong

if you have a full floating rear end, then yeah, similar strength to the 60 series stuff, although 60 series diff centers have a fine spline pinion, so are stronger than the earlier diff centers

Posted: Thu Apr 20, 2006 1:01 am
by beanz2
Depending on the month of production. Early (august 1975 and older) will have the weaker coarse spline CV. Late (September 75 and later) will have fine spline CV. Up until 12/78 the steering arms also have smaller studs and swivel stud pattern than a 60 series, these break more easily in spring over configuration. And as bad_religion said, until 1977 they have the weaker coarse spline pinion.

So, yes, 60 series diffs are better.

I think full floating diffs became standard in Aus. since 1974? Except for the Bundera and the 100 series of course.

Dave

Posted: Thu Apr 20, 2006 1:54 am
by bad_religion_au
beanz2 wrote:Depending on the month of production. Early (august 1975 and older) will have the weaker coarse spline CV. Late (September 75 and later) will have fine spline CV. Up until 12/78 the steering arms also have smaller studs and swivel stud pattern than a 60 series, these break more easily in spring over configuration. And as bad_religion said, until 1977 they have the weaker coarse spline pinion.

So, yes, 60 series diffs are better.

I think full floating diffs became standard in Aus. since 1974? Except for the Bundera and the 100 series of course.

Dave
yep, forgot about the steering arms.

and the fine spline cv between late 75 and late 78 is weaker, has less strengthened options, and has weaker freewheeling hubs

Posted: Thu Apr 20, 2006 4:09 pm
by Bighazza
Hmm thanks guys you have given me alot to think about

It is a semi floater rear, its a late 75 model (2F and 4 speed)
So i am guessing that it has the fine spline cvs ?

hmm bugger looks they will just become spares now

CHeers!