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Question - Rear end

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jlaird

jlaird

Great Pumpkin
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How do I tell what the final ratio is. I know it has been on here before and there are some numbers someplace on the pinion cover, where?

What the heck am I looking for?
 
Jack, looking at the aluminum housing from the front, there is a pad cast on at about the 11:00 position, just before the start of the mounting flange. There will be numbers there, such as 9/38. That's the number of teeth on the pinion gear, and the number on the ring gear. 9/38 would be for a 4.22:1 gear, stock for the Bugeye. I'm looking at one right now, stamped 9/41, which would be a 4:56:1. (4.555555555555555...) Just divide the big number by the little number. /ubbthreads/images/graemlins/grin.gif
Jeff
 
Ahhh, 9/38 it is. Had to use the paper and pencil tirck to raise the number, mine was not stamped too hard at all.

Thanks Jeff
 
But... the gears may have been swapped at some point. To be sure you need to count teeth or turns of the wheel and shaft.

You needed something else to do anyway... right Jack?
 
The numbers are on the ring gear as well, but I think that may have already been mentioned. I guess it more than posiible for someone to siwtch out the gears in the housing but Spridget diffs are easy to come by so I think most people just change the entire unit.
 
True Hap, but wouldn't you know I bought a 3.9 from someone only to find out it was 4.22 gearing. Didn't spend a lot on it, but frustrating none the less.
 
Yea right Hap. Spin on oil canister mount installed. Sliped right on nary a hitch. I am going to be real pleased with that mod and am sure the Healeys would approve.
 
Some thing that might help , if you jack up one wheel ( or if both are off the ground, lock one wheel ) put a mark on the free wheel and a mark on the drive shaft , rotate the wheel two revolutions while counting the drive shaft revolutions . A little less than 4 turns would be 3.90 gears , about 4 1/4 turns equals 4.22 gears , 4 1/2 turns equals 4.56 gears .
 
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