FJ40 3rd member in FJ60 housing

[dylanray]

I have a 1970 FJ40 with stock axles except for a lock-rite in the rear. I spotted a good deal on a pair of axles out of a 1986 FJ60 and was wondering if these would be good candidates for doing a spring over? I have read that they gear ratio is higher in the FJ60 so I was curious if my 3rd members would drop into these housings? That way I can keep my lock-rite and gear ratio without to much extra work?

 

[brian]

Those housings are wider than the 40 series

 

[pb4ugo]

The 3rd members are interchangeable. The lockrite will fit in either 3rd.

 

[reddingcruiser]

Your third members will fit the FJ60 housings. The housings are wider but the thirds will interchange. The 60 axles are fine for doing an SOA, but it's not a straight-across trade, especially on the front. On the rear you can add perches to match the 40 springs, but on the front you'll need to either:

1. French the spring perch into the banjo housing.
2. Outboard the springs. or
3. Use the 4plus extender sleeve to center the front axle and avoid 1 or 2.

Option 3, of course, means dealing with the rear axle width with wheel spacers or ...........

Have fun.

 

[dylanray]

All great responses thank you. I did know that the axles are wider which is fine but was unsure how the front 3rd member would effect the narrow spring mounting.

Glad to know that the 3rd members will swap because I like my 4:11's.

I've seen looking for a front disc set up for awhile now and I can get both of these axles complete, all the way down to the brakelines for $450. Seems like that's a pretty good deal.

 

[White Stripe]

The 3.70 fj60 3rd members come with a fine spline pinion shaft and is a lot stronger than old course spline pinions fj40s came with. If u have the course spline pinion 4.11 gears, I would go with the 3.70 gears for the strength. It's not fun breaking a course spline on the trail-and they will break especially with a spring over.

 

[reddingcruiser]

^^ True enough, but if your 1970 FJ40 has the stock tranny and t-case and your tires are bigger than 33's, the 3.73 gears are No Bueno for serious trails.

 

[White Stripe]

^^ True enough, but if your 1970 FJ40 has the stock tranny and t-case and your tires are bigger than 33's, the 3.73 gears are No Bueno for serious trails.

I imagine if u calculate to find final drive ratio low range with 4.11s vs 3.73s both numbers won't be very far apart at all, and both numbers will be fairly crappy.

 

[dylanray]

Yeah its rocking a full roller 350 SBC with 390ft/lbs and I have not had any problems. It has a late model 4 speed and T-case. Some day I'll set up a dual case because with the 268 cam and 35" tires low range is already pretty crappy with 4:11's.

As far as the pinion spines are concerned I believe mine are fine...I'm not sure which splines you are referring to though...are you talking about where the axle shaft enters the 3rd member?

 

[White Stripe]

Yeah its rocking a full roller 350 SBC with 390ft/lbs and I have not had any problems. It has a late model 4 speed and T-case. Some day I'll set up a dual case because with the 268 cam and 35" tires low range is already pretty crappy with 4:11's.

As far as the pinion spines are concerned I believe mine are fine...I'm not sure which splines you are referring to though...are you talking about where the axle shaft enters the 3rd member?

The pinion has a shaft on it that extends through the pinion bearing, third member and through the driveshaft flange. Those spines that go through the driveshaft flange in your cruiser are likely course spline. Landcruisers that came with 4.11 gearing had course spline pinions up to 77. In 78 all 9.5" differentials Toyota revised the differentials to fine spline pinions. The fine spline makes the pinion shaft much thicker and stronger. If u don't don't go offroad, or go offroad and don't have a rear locker you will likely be OK. If u have a rear locker, especially combined with a v8, it's a ticking time bomb. Google landcruiser course spline pinion and you'll see what I mean.

 

[4Cruisers]

The 3.70 fj60 3rd members come with a fine spline pinion shaft and is a lot stronger than old course spline pinions fj40s came with. If u have the course spline pinion 4.11 gears, I would go with the 3.70 gears for the strength. It's not fun breaking a course spline on the trail-and they will break especially with a spring over.

FJ62 third members have 4.11 gearing, plus the fine spline pinions.