Front differential 2 pinion vs 4 pinion unit? (1 Viewer)

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Joined
Feb 22, 2006
Threads
157
Messages
1,009
Location
Oregon
Excuse my ignorance but what does it mean?
 
the difference is...

No problem asking a question when you don't know. That's how we all learn, even though some of us won't admit it. I'll try to keep this very basic and simple.
The 98 & 99 UZJ100 had a "two pinion" design. The picture below shows the two "pinion gears" circled in RED and the side gears circled in blue. The side gears are splined and attach to the axles, and the pinion gears (or spider gears) ride on the pinion shaft and spin allowing the the tires to turn at different speeds when you go around a corner. If one wheel is in the loose stuff, the pinion gears are sending all the power to the spinning wheel. If the spinning wheel suddenly catches traction, all that power is sent back to the other side via the pinion gears. That's where things go terribly wrong and you hear things go snap, crackle, pop.
The "four pinion" style in the 2000 and up have a cross instead of a shaft and four pinion gears instead of two to absorb and transfer the power back to the proper wheel. Hope this helps, and your not too scared of the two pinion if you just use your rig in "normal conditions". Mine let loose under extreme rocking trying to get out of snow with ice underneath. The four pinion replacement has proven itself on the trail in loose rock, snow, ice, and mud.
manual1A.JPG
If your planning on serious offroading, look into an ARB Air Locker to replace the two pinion carrier in the diff, and you won't have any problem then.
manual1A.JPG
 
Last edited:
Thanks man:beer: :beer:

I am looking at a 2000 LX on Tuesday.
 
I am curious, my front wheels do not move when stuck in sand. Is this because of the 2 pinion?
Also, checked the part number for the later models and it’s the same for 98-07.
 
I am curious, my front wheels do not move when stuck in sand. Is this because of the 2 pinion?
Also, checked the part number for the later models and it’s the same for 98-07.

If your center diff is not locked and the rear wheels are both spinning then the fronts wouldn't move much. Lock the center and at least one of those front wheels should be spinning


As far as the part number maybe that's because those pinion gears and shaft are the same part, but they changed the spider shaft carrier (whatever it's called) to carry another shaft and added 2 more gears?
 
Last edited:
If your center diff is not locked and the rear wheels are both spinning then the fronts wouldn't move much. Lock the center and at least one of those front wheels should be spinning


As far as the part number maybe that's because those pinion gears and shaft are the same part, but they changed the spider shaft carrier (whatever it's called) to carry another shaft and added 2 more gears?
I bet it's just a superceded part...they don't sell you the 2-pinion version at all anymore.
 
If your center diff is not locked and the rear wheels are both spinning then the fronts wouldn't move much. Lock the center and at least one of those front wheels should be spinning


As far as the part number maybe that's because those pinion gears and shaft are the same part, but they changed the spider shaft carrier (whatever it's called) to carry another shaft and added 2 more gears?


The center is locked and the front is spinning until some point where both tires are deeply stuck...it is definitely working under normal/medium load. Does the 4 pinion make it perform differently, meaning it will handle slippage better than before? or it’s just make more reliable?
It looks very weak to me.👍
 
Every thing I’ve read said arb will strengthen this……. I just had an Eaton installed in my front on my 99….. does the Eaton do the same as far as protection?
 

Users who are viewing this thread

Back
Top Bottom