Hello all, i've acquired 4:10's for my 85' fj60. they are coarse splined at the flange and the fj60 flange is fine splined. is there an easy swap out there for this? any help would be greatly appreciated. thanks
fine spline to coarse diff?
- Thread starter rightlane
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there are round companion flanges available that have room to the pattern to match the FJ60 driveshaft pattern. I know man-a-fre carries them, I'm sure other do as well
- Thread starter
- #3
Man-a-fre wants to know what year the 3rd members from the fj40 are. i'm not sure. from what i read, having the 37x9 configuration makes them '78 or older, correct? thanks
I'd stay away from coarse splined gear sets unless you drive like an old lady and run the stock size tires. They break, fine splined don't.
zuluzeugma
SILVER Star
This is true; however, I've been running corse spline pinions in my FJ55 for over a year, I wheel hard with welded rear and 37" tires and haven't broke one yet (knock on wood).
- Thread starter
- #6
so how do i use a set of 4:10 diffs with a coarse spline? is this a lost cause?
I wouldn't worry about strength unless you wheel pretty hard, as long as the u-joint doesn't bind they will be ok. I have broken 2 coarse diffs, one was from a binded u-joint when my wrap bar failed the other was a legitimate fatigue break. I wheel hard on 40s, check the picture in my sig. I would put fine spline s*** in my truck if I could find em 
To your original question, I’m pretty sure the cruiseroutfitters flange is round with plenty of room to drill another pattern into. Or you could do some switcherooing on the drive shafts, put and different yoke on the ends..
To your original question, I’m pretty sure the cruiseroutfitters flange is round with plenty of room to drill another pattern into. Or you could do some switcherooing on the drive shafts, put and different yoke on the ends..
zuluzeugma
SILVER Star
Correct...
You make a half FJ60 half FJ40 drive shaft. Drive shaft splines are all the same... You should be able to pick a couple of those up on MUD CHEAP!
Take luck
