Outer Limits 4x4 Board

i've got a 1976 fj40, with 4.11:1 diff ratio, and i blew a rear diff. what year of cruisers are interchangable? i know the ratio dropped to 3.70:1 in about 1979, so which pre 79 diff centers will bolt in.

and could i get a front diff and put it in the rear?

any diff from 1976 to 1989 will be fine. The difference will mainly be in 19789 they went to fine spline pinion.

After that they went to a bigger flange too, so, could be a mission to do. A front diff will work in the rear, up until 1989, they were the same. They will ALL be 4.11 The 3.7s are so hard to get it aint worth trying.

Go the fine spline pinion there heaps better it was a Toyota update improvment.

what about a 12/75 fj40 what diff's would fit in mine? did they ever make an lsd that would fit in?

60 and 75 series diffs will all fit as well as 80 series rear
and they all had a lim slip option just make shore that you have
the right axel splin count ,flanges are easely changed

when changing flanges, do you have to set preloads and stuff? that's the only thing stopping me from rebuilding my destroyed diff, i'm a wimp when it comes to setting up diffs.

You don't have to reset the preload exactly but you can if you want to. It involves removing the diff from the housing, clamp it in the bench vise and use the Toyota SST for accurate settings and shimming.

However, it's no different to removing the flange just to change a leaky pinion seal. So approach it in that frame of mind.

Just be carefull in tightening it back up - don't over tighten to crush the spacer but don't leave it too loose either so it'll rattle off. If possible use a new pinion nut.

The 3.7:1 diffs were in the old 3 speed box 'cruisers - up to '73, easy to tell as they didn't have the full floating axles in the rear. Just the 3/4 axles.

If you plan on using the 3.7 behind a 4 speed for a slight overdrive effect use one in the front and one in the back. Don't laugh I've seen a 3.7 in the rear and a 4.1 in the front and the owner wondered why the tranny would lock up in 4wd.

If you want a LSD go for a new one. It won't be that much more than a 2nd hand one and it'll have warranty. Again I've seen LSD clutch packs worn out from abuse or wrong oil use and were charged a mint for a so called "A1" unit.

Hope this helps.

thnx for the help guys,

don't think i'll get an lsd, cause i'll get airlockers next year when i get a paying job. I've been reading too many american sites (they got 3.7:1 post 79.) and i wouldn't want to go to 3.7:1 anyway, i have enough trouble pushing 33's as is.

So what would be a fair price for a useable open third for my cruiser? i've so far got told $400 from a wrecker, guarenteed for 3 months.

Don't forget the private sales - someone wrecking a cruiser at home.

Try the trading post or local paper. For $400 you'd want drum to drum and the driveshaft!

hmm, i'll start looking privately. but i don't wan't drum to drum (no storage space)