Detailed pictures or knowledge of 60 series factory LSD? (1 Viewer)

[Eurasiaoverland]

For those with a factory 60 LSD or extensive knowledge of them, I have a bit of a mystery.

Last month I bought a used factory 60 series LSD, or at least that's what I think it is. It certainly came in a factory 60 series diff housing (-60040) with 45 mm carrier bearings. It is not the same as an early 80 series rear LSD.

All the Toyota diagrams that I have seen, from the earliest '7909-'8007 HJ45 (the oldest Landcruiser LSD I believe), all the 60 series diagrams I can find, ALL show 6 clutch discs (toothed metal discs) and 8 thrust washers (the textured, friction plates).

When I opened this LSD, it came with 4 clutch discs and 6 thrust washers (including the original factory outer thrust washers which are also shims). I assumed this was just incomplete as it came from a wrecker and has obviously been opened before.

However, when I stack the 3 clutch plates and 4 thrust washers in one half of the diff carrier, the spider gear assembly does not seat in the case - it's too high by several mms. It seems that this housing is really only designed for 4/6 plates, or perhaps 6/8 plates as shown, but with thinner versions of the plates (though I am fairly sure all 40/60/70/80 LSDs use the same plates (except European VM engines BJ73s).

So my questions are:

-Is there a factory Toyota LSD which has 4 clutch plates and 6 thrust washers?

-Does anyone have detailed pictures of a dismantled factory LSD for reference?

Thinking whether to run it as is, but I need to make sure it is what it is meant to be (not a patchwork of various mis-matched bits), and that I am putting the correct components into it. I could perhaps have 4 mm machined out of either side (there is plenty of space for that) to fit another clutch/thrust washer pair. I have plenty of large adjusting shims to set the spider gear backlash.

Some obvious points I wish to make:
-Everything is properly seated, dry (no oil).
-All new genuine clutch discs and thrust washers, matching what was taken out.
-There is no spring here, nothing to compress.
-I know Toyota factory LSDs are meant to be useless.
-I am not discussing non-factory LSDs.

Really appreciate any help here (less so speculation!).

EO

 

[Eurasiaoverland]

EDIT - I though this was a 45 mm bearing carrier, but it's actually 50 mm, meaning it comes from an 80. The cast iron housing is from a 60. Still does not explain the clutch/thrust washer count.

 

[Eurasiaoverland]

OK, case closed. After more searching the EPC I realise this is the centre from a late 80 series (1997+) LSD with a 60 series ring and pinion and 60 series housing.

Now, why did Toyota go from 8/6 clutch discs/thrust washer to 6/4? Surely that would not make the LSD any better? Or maybe the comparatively greater clamping force between fewer discs made it more effective??

 

[cruisermatt]

Now, why did Toyota go from 8/6 clutch discs/thrust washer to 6/4? Surely that would not make the LSD any better? Or maybe the comparatively greater clamping force between fewer discs made it more effective??

material improvements?

Good tech here as usual

 

[Eurasiaoverland]

material improvements?

Good tech here as usual

Very possible, but the clutch discs are the same as the 60, the thrust washers have a new part number but are the same size (and much cheaper). Not sure how much scope there is to improve the material on one of these...

I suspect it's an 'improvement' along the lines of converting to IFS or outsourcing the Hilux to be built in Thailand....

 

[cruiserpilot]

The BJ74 came with a factory LS. I’ve got two with what I learned to refer to as 4 pinion LS.
They are developed during late run of 60’s then into 80’s development time period. I never
really looked at them but I did stick one of them in my 60 FF rear. The 70 and 60 series parts
have better interchangeability than with 80 Series stuff. The unit I used worked so I never took
them apart or looked too hard at them. This is a diagram from Megazip BJ74 for reference.
Identical part numbers to your diagram.

Rear Axle Housing & Differential for 1986 - 1990 Toyota LAND CRUISER BJ74 | General sales region, , 18023585-936152

Looking for genuine OEM Rear Axle Housing & Differential for 1986 - 1990 Toyota LAND CRUISER BJ74 (General sales region, , 18023585-936152)? Check on MegaZip at discounted price from manufacturers' warehouses in Japan, USA, UAE. Detailed diagrams & catalogues. Worldwide shipping. Easy to find...

www.megazip.net