will a 60 series front diff center section bolt into the rear diff of my bj74 ? My rear pinion bearing and seal are giving up on my 74 so Im looking for the easiest fix and I have a 60 series parts wagon I can scavenge from.
diff question
- Thread starter bigtreads
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Josie'sLandCruiser
Stop calling it a "FJ."
Hi All:
Yes, a 60 Series differential "third member" will bolt-up into your BJ74 rear axle housing. The front diff is actually a great replacement, usually low miles.
What you need to figure out is what axle ratio your rig has.
If 3.7 ratio a US-market FJ60 is a good donor; if 4.1 ratio a US-market FJ62 is an excellent donor. Canadian-spec BJ60s have 3.7 ratio diffs.
Regards,
Alan
Yes, a 60 Series differential "third member" will bolt-up into your BJ74 rear axle housing. The front diff is actually a great replacement, usually low miles.
What you need to figure out is what axle ratio your rig has.
If 3.7 ratio a US-market FJ60 is a good donor; if 4.1 ratio a US-market FJ62 is an excellent donor. Canadian-spec BJ60s have 3.7 ratio diffs.
Regards,
Alan
Last edited:
Fit exactly!
crushers
post ho
and the HJ60 has 4.10 ... direct bolt in
don't mix the ratios
or
pull out your wallet.
don't mix the ratios
or
pull out your wallet.
- Thread starter
- #6
My parts wagon is a Canadian 1981 bj60 3B with 4 speed. So I guess the ratio will be wrong if my Bj74 has 410 stock and the bj60 has 373 - bummer 
- Thread starter
- #7
so if Im going to have to source a different third member from some one local - which 40 series thirds will work ? I know that the spline count changed as well as ratios in the 40 series just not sure the years.
Josie'sLandCruiser
Stop calling it a "FJ."
Hi All:
Chances are most 40 Series third members you find for sale have coarse-spline pinions. You could use one of these older third members if you utilize the adapter flanges from Cruiser Outfitters.
Cruiser Outfitters
Honestly, a fine-spline third member from a FJ62 is a better bet for the rear axle.
BTW, I dunno what ratio diffs a Cdn.-spec '81 BJ60 with a 4 speed came with. Maybe Crushers can advise on this?
Good luck!
Alan
Chances are most 40 Series third members you find for sale have coarse-spline pinions. You could use one of these older third members if you utilize the adapter flanges from Cruiser Outfitters.
Cruiser Outfitters
Honestly, a fine-spline third member from a FJ62 is a better bet for the rear axle.
BTW, I dunno what ratio diffs a Cdn.-spec '81 BJ60 with a 4 speed came with. Maybe Crushers can advise on this?
Good luck!
Alan
Yes! exactly. 40, 60, 70 share the same diff housing, except the for HZJ series the front diff is we called "small diff " ,other than ratio and the flange is another issues. Or LSD is another.
Late HZJ another designed housing but still direct bolt in.
crushers
post ho
the coarse spline pinion is a fine unit, as long as the back lash is good then seldom will you snap it off.
the biggest problem i see is most of the older center units are worn and people with heavy right foot tend to break them on the trail.
i have yet to see coarse or fine in good condition break off on the highway.
i have now come across my first even heavier pinion Land Cruiser unit. I ordered a e/locker from Dave at Japan 4X4 and found the pinion is about 3/16" larger than the normal fine spline unit. that makes for one hell of a strong pinion shaft.
BJ60s in Canada came with 3.70
the biggest problem i see is most of the older center units are worn and people with heavy right foot tend to break them on the trail.
i have yet to see coarse or fine in good condition break off on the highway.
i have now come across my first even heavier pinion Land Cruiser unit. I ordered a e/locker from Dave at Japan 4X4 and found the pinion is about 3/16" larger than the normal fine spline unit. that makes for one hell of a strong pinion shaft.
BJ60s in Canada came with 3.70
Do they have the 3.7 ratio small diff for my front 75? Please give me the part no if yes. One more thing, what is the diff ratio for FZJ75?
crushers
post ho
if there is one, i want it. i would love to have a 3.7 in the pickup. the increase in fuel mileage, top speed and quieter engine would make the swap appealing in my view...
i will check into it.
i will check into it.
Hey! Clint
This is what I want for my 75 with what Crusher has mentioned.
Wait for your good news, Crusher!
Doesn't marks 4wd adapters make a kit to drop 5th gear rpm
Maybe you could use taller tyres Wong to drop freeway rpm.
The 3.7s are very popular with those that like to waste $20,000+
on those waste of time overheating slug 6.5 v8 chev diesels conversions in there cruisers.most the 85-89 75 series use diffs from the 3speed 40 series , not sure about post 1990 cruiser owners to what they use , maybe brand new gears.
Maybe you could use taller tyres Wong to drop freeway rpm.
The 3.7s are very popular with those that like to waste $20,000+
on those waste of time overheating slug 6.5 v8 chev diesels conversions in there cruisers.most the 85-89 75 series use diffs from the 3speed 40 series , not sure about post 1990 cruiser owners to what they use , maybe brand new gears.
You sure $20,000+
Why so expensive? Only the gear set, right!What kind of kit does 4wd adapters has to offer to drop the rpm?
