Information Needed on FJ80 Electric Lockers

[Sputnik40]

Posting here as I know that Dan, Marshall and others seem pretty savvy about these 4 pinion FJ80 diffs???

I'm in research mode for my latest build up. Up in the air is what t-case to go with, Orion HD, Atlas or Stak. Orion is a bolt in. The Atlas or Stak would require a centered rear axle. While I have the D60 sitting at Alan's shop (cost to rehab unknown), I was really impressed with the Diamond axle write up for Ben's Raisen from Slee!

Soooo, Ben used the FJ80 four pinion diff due to it having larger bearings that could be machined out for D60 axles. What is a four pinion diff? I know it doesn't have four pinions - so what does that mean? Are the 9" electric locking diffs the only one with the larger main bearings? If not, how do you tell?

Many thanks! Bill.

 

[GXO]

Sorry, havent been here much.

A four pinion diff is one with 2 sets of spider gears. Most LCs have them, but 80s are MUCH stouter.

Ben bought my old diff for his 40 .

I believe the main bearing (pinion bearing) is the same part for locking an non-locking differentials. You could get a non-locking rear 80 diff, add ARB, ez, etc and be good to go for a front locker. The front 80 diff would not work for you, as it is high pinion and would probably need some work to fit your housing and you want the beef of the rear diff.

 

[Sputnik40]

Thanks Dan - Halfway to an answer. Four pinion means 4 spider gears - never would have figured that - especially, since I've got a pile of that junk around somewhere I'm saving for welded art - who uses those anyways .

Aren't fronts 8" anyways - not just high pinion?

Need a bit more confirmation on the references on exactly which diff has the larger bearings. The project in mind was written up in Crawl and involves taking a centered diamond axle, a "four pinion FJ80 diff" with the bigger main bearings (they specifically used an old locking diff without the locker) and then you weld in a pair of D60 35 spline side gears (spider gears), and then buy a D60 conversion kit to run 235 spline axles (this is the kit) that have Toyota outers. To do this, they machined extra material out of the "larger" bearings to enable the larger 35 spline shafts to get into the carrier. The D60 bearing retainers seem to hold it in similar to a full floater, but the axles aren't full floaters. Some more mods would be needed to convert my disk brakes over - but no biggee. It was a damn kool centered axle!

Soooo, can anyone verify - do all FJ80 rear diffs have the same "larger" main bearings, or are do the locking diff versions have even larger carrier bearings???