third member and gearing questions

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shmukster

shmukster

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I'm gonna be putting 4.56 gears in my BJ70, along with a pair of ARB lockers. I have two third members in my garage from an early FJ40, maybe a 74. Are the housings on an older third member the same as the later housings? Are they as strong? Any reason not to use older thirds as candidates for my locker and new gear install? Should I just yank the thirds out of my 70 and install the gears and lockers in those housings? And where's the best place these days to buy gear sets, ARB lockers, and install kits for what i want to do? Thanks for your input. Shmukster
 
shmukster said:
I'm gonna be putting 4.56 gears in my BJ70, along with a pair of ARB lockers. I have two third members in my garage from an early FJ40, maybe a 74. Are the housings on an older third member the same as the later housings? Are they as strong? Any reason not to use older thirds as candidates for my locker and new gear install? Should I just yank the thirds out of my 70 and install the gears and lockers in those housings? And where's the best place these days to buy gear sets, ARB lockers, and install kits for what i want to do? Thanks for your input. Shmukster
Click to expand...

Depending on how old the third members are they will at least have different (probably not as big and strong) bearings on it. I am not sure but if they are old enough I think the axle shaft spline count is also different.

What size tire are you running that you want to go with 4.56's?


Michael
 
If you are going to re-gear and lock these spare 3rd's then no biggie. The 3rd member housings are the same. As for gears and lockers, I know of a great place to get those:) But really, we have hundreds of cruiser gears in stock ready to ship.

shmukster said:
I'm gonna be putting 4.56 gears in my BJ70, along with a pair of ARB lockers. I have two third members in my garage from an early FJ40, maybe a 74. Are the housings on an older third member the same as the later housings? Are they as strong? Any reason not to use older thirds as candidates for my locker and new gear install? Should I just yank the thirds out of my 70 and install the gears and lockers in those housings? And where's the best place these days to buy gear sets, ARB lockers, and install kits for what i want to do? Thanks for your input. Shmukster
Click to expand...
 
gears

The 3rd member housings are the same, & we carry tons of gears, lockers, bearing kits, knuckle kits, etc.


lshobie said:
Use the diffs out of your 70, not sure where the best place to buy a locker in the states is, i think marlin crawlers sells gears and lockers.
Click to expand...
 
ringpinion.biz said:
The 3rd member housings are the same, & we carry tons of gears, lockers, bearing kits, knuckle kits, etc.
Click to expand...

Hmm, you guys are the experts but how can the housings be the same when the bearing are different on some years, would'nt the housings and bearing caps also be differnent to accomodate the bigger size bearings? Just curious here.

Michael
 
Although bearings may have different numbers, they are the same dimensions. The outer diameters, and the depths of the bores in the housings are identical. In fact they are dimensionally the same all the way up through 1997, (although 91-97 cases have much more gusseting). So, yes, you can use your old housings, they are the same.


tlcruiserman said:
Hmm, you guys are the experts but how can the housings be the same when the bearing are different on some years, would'nt the housings and bearing caps also be differnent to accomodate the bigger size bearings? Just curious here.

Michael
Click to expand...
 
the center units are the same as in they will bolt up.
the 77 and up have a fine spline pinion (but since you are switching them out, no biggie)
ALL the older than 76 had 4.11 gearing, 76 and newer could have either 4.11 or the 3.70 up to 1990.
the case themselves are interchangeable.
i would keep the 70 series stock and do the conversion to the older case. this way if you ever change your mind it is an easy swap back andyou can sell the 4./56 already installed and set up as a unit (worth a lot more on the resale market)

but<see sig line>
 
ringpinion.biz said:
Although bearings may have different numbers, they are the same dimensions. The outer diameters, and the depths of the bores in the housings are identical. In fact they are dimensionally the same all the way up through 1997, (although 91-97 cases have much more gusseting). So, yes, you can use your old housings, they are the same.
Click to expand...

Thanks, A sesson well learned :)

Cheers,

Michael
 
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