3rd Member Interchangeability?

[jaymar]

Time to hit the boneyard for "new" diffs to use in regearing. Seem to recall not all 3rd members interchangeable without mods, so...

Which front and rear 3rd members fit NON-factory locked '95 80 with no modifications needed?

While we're at it, which gear ratios require cutouts for clearance? I'm going 4.56 with aftermarket lockers, don't THINK clearance is an issue...

Thanks for any help!

 

[SoCal FZJ80]

91-97 for front are Full Float all years (91-92 no ABS sensors or tone rings on outers)

93-97 for rear are Full Float for 4 years

91-92 is Semi Float rear (with drum brakes and no ABS sensors on outers)

No housing cutting necessary when only changing ring gears.

Only housing trimming necessary when installing an eLocker 3rd into a non-locker housing.

Why not just re-gear your 3rds instead of investing in more 3rds???

Leaves more money for other mods

 

[mudgudgeon]

Which front and rear 3rd members fit NON-factory locked '95 80 with no modifications needed?

While we're at it, which gear ratios require cutouts for clearance? I'm going 4.56 with aftermarket lockers, don't THINK clearance is an issue...

Are you asking about 3rds from different series? or different vehicles?

For 80series stuff, Factory locked centres wont drop into a NON factory locked housing (front or rear) with out the help of a grinder

ratio change shouldn't create any clearance issues

 

[jaymar]

Are you asking about 3rds from different series? or different vehicles?

For 80series stuff, Factory locked centres wont drop into a NON factory locked housing (front or rear) with out the help of a grinder

ratio change shouldn't create any clearance issues

Thanks! Plan to use 80 3rd members, but would be interested to hear what else fits as well. Some gear ratios do require clearancing, but I don't think 4.56's do. Damned near sure I saw something somewhere about another 3rd member incompatibility, don't recall what. Will stick to 95/96/97 if possible, just to be on the safe side...

 

[jaymar]

91-97 for front are Full Float all years (91-92 no ABS sensors or tone rings on outers)

93-97 for rear are Full Float for 4 years

91-92 is Semi Float rear (with drum brakes and no ABS sensors on outers)

No housing cutting necessary when only changing ring gears.

Only housing trimming necessary when installing an eLocker 3rd into a non-locker housing.

Why not just re-gear your 3rds instead of investing in more 3rds???

Leaves more money for other mods

Ah, thanks! Gotta send my thirds/gears/lockers to Zuk, but can't afford the downtime on my DD.

I HOPE you mean housing trim necessary when installing FACTORY elockers into non-locker housings. I'm going with aftermarket Harrop Eaton ELockers and my understanding is, no housing trim required...

 

[Mandrake]

Pretty sure nothing else fits the 80 housings except 80 3rds. Reverse engineering my faded knowledge of mini truck axles, any 8" Toyota 3rd will fit the front, but the low pinion will occupy the same space currently used by the tie rod.

A friend has the Harrops on his non- factory locked rig and were direct bolt ins other than a small hole that had to be drilled for the wires. You'll love them.

 

[hoser]

For the rear, 40/50/60/70 9.5" 3rd members will fit your 80.

 

[SoCal FZJ80]

"I HOPE you mean housing trim necessary when installing FACTORY elockers into non-locker housings. I'm going with aftermarket Harrop Eaton ELockers and my understanding is, no housing trim required..."



You Are correct:

Trimming only necessary if installing OEM Toyota aLocker 3rd into non-locker housings.

If running Harrop eLocker conversion kits, no housing trimming is necessary.

 

[LandCruisinMy93]

For the rear, 40/50/60/70 9.5" 3rd members will fit your 80.

I may be wrong, but I thought that the 40/50 series were coarse splined....so they may physically fit in the housing but would be incompatible with the rest of the axle. I'm not sure on he 60 series so I won't comment.

 

[hoser]

I believe, the coarse splined axle shafts are pre 1970. Coarse spline pinion shaft were pre '79 or so. In any case, the OP is regearing and installing aftermarket lockers... so pinion and axle spline count will be fine splined.

 

[Tools R Us]

Ah, thanks! Gotta send my thirds/gears/lockers to Zuk, but can't afford the downtime on my DD.
...

To do this, get a rear third, snatch both of yours out, install the loner rear, leave the front empty, no drive shaft, diff, axles, etc. Lock the CDL and drive RWD until they come back.

 

[Cruiserdrew]

To fit in a rear 80 housing, any Land Cruiser 3rd member will fit from early through 90 and rears 91-97. You may need to change flanges to get the bolt pattern right but all will work.

The high pinion front is unique Land Cruiser 91-97.

Thanks! Plan to use 80 3rd members, but would be interested to hear what else fits as well. Some gear ratios do require clearancing, but I don't think 4.56's do. Damned near sure I saw something somewhere about another 3rd member incompatibility, don't recall what. Will stick to 95/96/97 if possible, just to be on the safe side...

4.56 fits fine. Just as a for instance-I have an 80 axle housing in my FJ60, with an 83 3rd member, swapped to 4.56 gears and a new companion flange. Details here:

Harrop elocker FJ60 456 Nitro gear install

Regarding 4.56 and clearencing--you need to grind 1 or 2 ring gear teeth slightly to fit the cross shaft in a semi-float axle with c-clips.

To do this, get a rear third, snatch both of yours out, install the loner rear, leave the front empty, no drive shaft, diff, axles, etc. Lock the CDL and drive RWD until they come back.

^Do this^

Likely one of your buds will have a 3rd you can borrow for a couple of weeks. But Zuk is worth the wait.

 

[wardharris]

What Andrew said!

 

[LINUS]

@jaymar - if you have some flexibility in who does your gearing, the guys up here at Just Differentials (forum vendors here)/ Cashmere, WA - probably have a set of cores they can gear for you, then send them your old 3rds. Almost all pricing is based on you sending cores IIRC.

JustDifferentials.com

They bought my set of open K292's I was flat swapping with a set of K294's w/ 4.88's, and they do custom setups.

At least go check the custom axle shells they vendor (IDK who makes them, I'm not trying to make a PRO-4 truck out of my 80) - they're cool to look at.

At least if cores become a PITA to send to Zuk, it's an option.

I'm very happy with the gears they did & they reworked my LX450/5.29&ARB's the PPO had self-installed & whiffed, then my buddy I bought it from took it there & they didit right, (even ran lines & firewall mounted the breathers as it really is the best way to bombproof your axles) fixed it to the point I never once had an issue even ~3 yrs past fix when I sold it, I just would excercise every couple weeks when just driving around town.

HTH.

 

[robstar]

Hi - riding on the thread, would a 60 series '80-'81 9.5 in. gear and pinion set fit into an '81 40 series differential ?
Thanks.

 

[Cruiserdrew]

Hi - riding on the thread, would a 60 series '80-'81 9.5 in. gear and pinion set fit into an '81 40 series differential ?
Thanks.

Direct swap. Even the flange and gear ratio would be the same.

 

[robstar]

Thanks for the reply Cruiserdrew. What If I change the gear ratio from 4.1 to 3.7 ?

 

[LINUS]

Thanks for the reply Cruiserdrew. What If I change the gear ratio from 4.1 to 3.7 ?

The obvious answer (not sure if what you are after)-is that it's a taller gear so you'll be able to have a higher top speed or less RPM's at equal speeds with 3.7 over 4.1, but less felt torque/takes longer getting there with the 3.7 vs 4.1.

Not sure how you mean that, but I want to say 3.7 is a diesel gearset (probably semi-wrong, but maybe a JDM 80 diesel gearset??), are you after that/glowplugged 40 gearing?

Or are you asking if the ring gear bolts up/needs clearance to fit the axle shell flange?

 

[Cruiserdrew]

In the USA all FJ40s 79 up and all FJ60s came with a 3.70 gear ratio installed from the factory.

 

[LINUS]

In the USA all FJ40s 79 up and all FJ60s came with a 3.70 gear ratio installed from the factory.

I had a feeling my facts were/are off/incomplete. Good to know, I'm only versed in FZJ's - outside these I'm 20% on a good day.