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4.10 gears on limited slip 7.5 differential

Glen MC

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Hello everyone, I am wanting to put 4.10 gears 84 Bronco ii in my 7.5 limited slip rear end. once I put the 4.10 ring gear on my Differential that had 3.75 gears I cant get the pin in. the Ring gear seems too thick to allow the pin to go in. I have a 5 speed Trani 4 wheel drive. Thanks for any help you can provide to fix this or any alternatives. I'm not sure which other rear ends will fit if I need to go that route."
 


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Blmpkn

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Your re-gearing the front too correct? If not... don't use that 4x4.
 

sgtsandman

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A tooth or two needs to be ground down in the back to make clearance for the pin to go in. It’s a proven practice that works.

Alternatively, there are pins out there designed for lower gearing like that. If I remember correctly, the center is dished out some to allow the pin to clear the ring gear.
 

bobbywalter

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Just nibble it wit a die grinder or file ..roto zip ..
 

ecgreen

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I got pics from when I did mine. Hold on a sec
 

ecgreen

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I used a demel and it worked fine. Pic the side thats going to need the least amount of removal, then slowly start grinding the teeth down. Keep checking to see if you can slide the pin out every now and then. Keep doing this until it just slides out. Clean up and make sure everything is smooth and free of shavings. I have 1000+ miles on this gear and no issues at all.
 

Mechrick

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The other option is a notched pin. The notch is so the pin can be installed before the ring gear. You rotate the pin left and right so the axles can be pushed in and the C clips installed, then turn the pin 90 degrees and install the retaining bolt.

There is a running debate on which is stronger, grinding teeth on the gear or grinding (replacing) the pin. In your case, I would say swapping that 7.5 with an 8.8 is the answer.
 

.38spl

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My 7.5 came from a 1985 2.8 Ranger, and is a factory 4.10 L/S. It has a notched pin, I'm assuming is factory.
 

gaz

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ecgreen,

Genius pics!!
 

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