Advice from diff experts?

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Dec 24, 2011
Lima, Peru
Hello all,

I am in a bit of a dilemma. I was having front and rear e-lockers installed and decided to overhaul everything on the axles at the same time. Its a 2002 HZJ78L with open diffs. Turns out the previous owner has changed the ring gear and pinion on the rear diff. Thankfully its still a 4.3 like the front, but I found out because the new rear oil seal and the new drive pinion flange 41204-35100 doesn't fit. The flange that's supposed to be there has an external diameter of 41 mm and 29 teeth, which would mate to the correct oil seal and pinion shaft respectively. The worn flange that has been used is 38mm diameter and has 27 teeth. Thus the pinion shaft between the flange and ring gear has a smaller diameter than factory, now 28mm (615.752 mm2) instead of 30mm (706.858 mm2). Thats a 13% reduction in shaft thickness, which is what worries me. If there is a Hilux 43:10 final diff gear I'd bet money thats what they fitted at the mine.

So my issue is whether I can I trust this smaller pinion shaft, considering I have a turboed 1HZ-T and GVM of 3.6 t. I don't really know how often they tend to fail or how over-engineered they are in general.

There's also another possible issue of whether I can actually get an oil seal to fit the casing with the smaller diameter, that seal was never good since I had it, but not knowing the age I just thought it was spent, I'm now thinking it is related.

Any ideas on where these invasive parts might have come from and how risky it will be to stick with them will be very welcome.

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not a single chance you ( someone ) can make a 8" ring ( from HI Lux ) fit on a Cruiser 9.5 carrier ..
Good to know, I wonder what other vehicle shares the same ring. Is it at all possible that a hilux pinion could fit a cruiser ring? I ask cause the mine where she lived has about 300 hiluxes and very little of anything else
Probably aftermarket r&p and came with its own flange/seal.
That makes sense. I'm thinking even if the smaller pinion shaft is strong enough, i might have to get a whole new set just for the seal. Do you know of any potential brands?
Did a bit of digging around the interwebz and found that these can vary a little, found an oil seal for a 38mm flange (90311-38047) and a repair sleeve for a 38mm flange (90311-99147). Don't quote me on those numbers, they are not confirmed yet, but at least I'm seeing that my ring and pinion could be of toyota origin and designed for a landcruiser, which was my biggest worry, although I would still prefer the same thickness as the front.
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could be a happy ending... after more surfing around, I think I've determined that my model came with a 38mm flange (and 28mm pinion) up till 12/2001, while mine's a 03/2002. so it seems likely it was either repaired with that size, or it could have even come from the factory like that. anyway, the part numbers are distinct so by the end of the day i might be all sorted (or desperately air freighting parts from abroad), but it seems i won't have to worry about changing out my ring and pinion after all, though next time i'll plan to do that i think. The things you learn from hiccups!
Slightly happy ending, found the flange and seal to suit, and mine is OEM, either the catalogue isn't correct or ir took them 3 months to fit the last remaining older flanges.
If thinking about replacing R&P Nitro Gear ( from ) or Yukon are great options .. in the case of Nitro in the website youc an get matching flanges and installation kit with bearings and all needed stuff ..

Same thing you can get from Kurt in

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