Topic: weird rear end gear problem

[tech201]

my truck 1980 pick up has a 10 spline pinion in the rear diff i no the fj40 had a 10 spline pinion but isn't the ring gear 9.5 inches. so how could that fit in my 8'' diff?? or maybe its from a pre 79 2wd if so is the third the same as the 79 and later 4wd so i can put a set of Yukon gears in to match the front?? thanks guys.

[79coyotefrg]

can you post a pic of this rear diff??

it must be some sort of early 2wd rear so

[tech201 [OP]]

here is a pic of the pinion and flange when i seen this i new somthing wasnt right will get more tomorrow.

[RN37DD]

looks just like the 4wd 79-83 pick up 3rd to me. i just pulled a rusted 4.11 apart to get the solid spacer for an 88 3rd I'm getting ready to regear. has the same 10 spline pinion shaft on the 79-83 diff. when you get your R&P you'll want to also get a new style flange. but they have 10mm bolt hole's. so if your going to buy new, a triple drilled flange might bet the trick thing to do. or if you have a 84 or newer flange laying around, you can drill it to fit the old bolt pattern. 8 or 9mm.

[79coyotefrg]

  must be leftovers from 1978 year    never saw one of those myself

[bluetoy84]

That's odd. I agree with 79coyote, I've tore apart an awful lot of '79-'83 diffs and have never seen one with the course spline. Strange to say the least.

[RN37DD]

yeah i don't know the whole history of that 3rd, and you never know what your going to find in an old truck. the ratio was 4.11 and a 1979 should have been 4.37. and it looked like a factory R&P too. 78 would have been 2wd.. were they running 4.11's?

[79coyotefrg]

the 2wd "heavy duty" trucks had 8 inch r&p  and many had the 4.10 ratio,  is it 4.11 or 4.10??  toyota's are usually 4.10

8 inch 4.10 ratio = G292 axle code

[RN37DD]

9x37 ring and pinion. 4.11  it's cleanly stamped right on the pinion shaft along with a little teq or something that looks like that. only other numbers on it was 82 and 77. i counted the teeth 9x37. the Toyota 4.10 R&P is a10x41 i believe. I'm no expert on 3rd's. i pulled this one apart to get the Toyota solid spacer out. i plan to use it in a newer 3rd i'm going to attempt to rebuild and regear.