Need More Info. on 8" Diff. Compatibility HELP

[Sputnik40]

Have been trying to help a friend of my Pop's with his 80 mini truck. Posted here earlier with questions on 8" diffs. He needs a new carrier so he can build up his front one as it's screwed due to bad pinion set up and welds breaking free (previous owner).

Anyways - I've got a whole front axle with carrier donated from SC - but we can't get that for awhile.

Another friend has offered up one of the better V6 rear diffs - not knowing anything about them is this compatible with the ring and pinion from a standard diff AND since he's already bought a new locker are the internal dimensions/setup the same???

 

[knixen]

Have been trying to help a friend of my Pop's with his 80 mini truck. Posted here earlier with questions on 8" diffs. He needs a new carrier so he can build up his front one as it's screwed due to bad pinion set up and welds breaking free (previous owner).

Anyways - I've got a whole front axle with carrier donated from SC - but we can't get that for awhile.

Another friend has offered up one of the better V6 rear diffs - not knowing anything about them is this compatible with the ring and pinion from a standard diff AND since he's already bought a new locker are the internal dimensions/setup the same???

I think you misunderstand a few tech-names here, It sounds like he needs a whole 3rd member (the complete diff). The rear V6 diff does fit, but you have to do a tooth count to check if the gearing is correkt. Which I doubt. I belive early minis has 4:56 and 4:88s (?) and a v6 har 4:56 or 4:30. (I THINK)...

The carrier is the part which the lunch-box locker fits into. And is also the part which the ring is mounted on, and also the ring bearings. If you have a LSD diff from before, you need new bearings ifs you just replace the carrier with an open one. The open carriers need bearings with 45mm inner hole, while the lsd or ARB needs one with 50mm inner. The outer is 80mm. SKF nr for the arb/lsd is 32010. Don`t know the number for the open carrier.

I have no pix here, but you could check gearinstalls.com for further info.

I hope this was helpfull, and I might have misunderstood... I`m from Norway...

 

[fourwd1]

1980 trucks had 4.38 gears.
The common 4.10 ratio is found in 4 cyl/5 spd trucks from 1982 on.
Auto equipped trucks and those with the factory 31" tire package were geared lower - 4.30, 4.56, 4.88.
I sorta remember some incompatibility between 4 cyl and 6 cyl diffs, but I think it was only 4.88 V6 diffs.

As far as the 4 cyl ARB working in the 6 cyl diff, check ARBs site and see if they list 2 different p/n's.

Randy's Ring & Pinion site also has a lot of useful info.

 

[Downey]

I'm thinking ok on what your trying to do (if I understand correctly) because the 35010 gskt used on 79-83 and the 60020 gskt used on V6 rear are the same bolt-up pattern, and because the standard rotation 8" R&P's are same 4 cyl and V6, only with the V6's requiring an extra .125 thick shim.

 

[Letsgomoreplaces]

diffs

The 3rd members are interchangeable in that they will bolt up, but you need to check your ratios. If you have a lockright style locker for the 4cyl diff, it will not fit in the 6 cyl diff.

 

[Sputnik40]

Ok - Everyone is close but I'll try and clarify...I appreciate everyone's patience . Simply put: Can the ring, pinion and lunchbox locker out of a 8" 4 cyl. diff. be installed in a V6 8" diff???

Technically he only needs a new carrier for an 1980 4 cyl diff. The outer thrust washer surface of the carrier got boogered by a piece of broke off weld that got wedged in (PO Lincoln locker gone bad). The diff housing was not damaged. Technically from what's they've e-mailed me and shown in pics I'd be tempted to clean it up and reinstall with new thrustwashers if he was in a hurry - would'nt really hurt anything; but since he is installing a new locker and his 5.29 ring and pinion (e.g. we don't care about gear ratios) - might as well do it right.

That brings him to just finding a complete diff (sans ring and pinion - but including carrier) to use for a rebuild. The mini axle that I landed him for free from a fellow FJ40 guy in SC has the complete diff - but he doesn't have time to ship - and we can't have anyone pick up for several weeks (months)...

Soooo, another friend has offered up a V6 diff (complete third). From the last post above it sounds like the ring and pinion are the same and interchangeable? But there is a difference in how a locker fits in the carrier??? If it is just a bearing issue - sounds like they make different ones to accomodate changes made when V6 diff came out.

 

[2ndGenToyotaFan]

I will clairify some more.... or maybe less.... I think 4 cylinder ring and pinioins can be installed into a V6 carrier with some of the V6 bearings. But not V6 gears into a 4 banger carrier. The stock 4.88 uses a different carrier altogether, it will still fit all 8 inch axles, but the guts are all different. I don't think a locker for a 4 cylinder will fit in a V6 carrier.

 

[GRM]

From the best of my knolwedge, no the carriers are very different. The 4cyl open carrier is a one piece unit that uses a single cross pin, while the v6 carrier uses an X cross pin, and the carrier is a 2 piece unit that bolts together.

But there is a way to put a 4cyl carrier and 4cyl ring and pinion in a 6cyl differential. I believe you use the 4cyl bearings for a 79-85 differential as they are designed for a shorter pinion head that came in these years. v6 diffs used a long pinion head. The same goes the other way if you wanted to put 4cyl gears in a v6 differential.

 

[Letsgomoreplaces]

gears

Can the ring, pinion and lunchbox locker out of a 8" 4 cyl. diff. be installed in a V6 8" diff???

Ring & pinion will work (if it is out of an 85 or older it will require an additional .140" shim)

Lunchbox locker WILL NOT work as the 4cyl diff is 2pinion vs/ 4pinion of the v6 diff. And no, you cant use a 4cyl diff case in a v6 housing, as the carrier bearing journals are too small.

If you just need a 4cyl diff case we stock them, among everything else.

Ok - Everyone is close but I'll try and clarify...I appreciate everyone's patience . Simply put: Can the ring, pinion and lunchbox locker out of a 8" 4 cyl. diff. be installed in a V6 8" diff???

Technically he only needs a new carrier for an 1980 4 cyl diff. The outer thrust washer surface of the carrier got boogered by a piece of broke off weld that got wedged in (PO Lincoln locker gone bad). The diff housing was not damaged. Technically from what's they've e-mailed me and shown in pics I'd be tempted to clean it up and reinstall with new thrustwashers if he was in a hurry - would'nt really hurt anything; but since he is installing a new locker and his 5.29 ring and pinion (e.g. we don't care about gear ratios) - might as well do it right.

That brings him to just finding a complete diff (sans ring and pinion - but including carrier) to use for a rebuild. The mini axle that I landed him for free from a fellow FJ40 guy in SC has the complete diff - but he doesn't have time to ship - and we can't have anyone pick up for several weeks (months)...

Soooo, another friend has offered up a V6 diff (complete third). From the last post above it sounds like the ring and pinion are the same and interchangeable? But there is a difference in how a locker fits in the carrier??? If it is just a bearing issue - sounds like they make different ones to accomodate changes made when V6 diff came out.