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Discussion Starter · #1 ·
I just bought a 2.47, 9", open rear pumpkin for my 67, 289, C4 fastback from a rear end rebuilder. He used a 2.47 ring and pinion from a Lincoln and rebuilt the rest of the unit. I have two questions:
1) Does this rear end have to be “broken in” in any way, and if so, what’s the procedure?
2) What rear end oil should be used? 85/ 90 or 85/160. What’s the difference between them? It’s my understanding that the first number is the actual weight of the oil, and the second number is the equivalent protection of the oil, that is, the oil will protect to the same degree as the weight oil of the second number. For example, 85/90 oil is the viscosity of 85 weight oil, but affords the protection of 90 viscosity (weight) oil, whereas 85/160 oil is the viscosity (weight) of 85 oil, but affords the protection of 160 viscosity (weight) oil. If this is correct, then it follows that 85/160 oil should be better to lube the rear end than 85/160 oil.
This all sounds perfectly logical, but I’m not sure it’s correct!!! Can anyone out there set me straight on this?
Thanks
Jay67fast
 

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Discussion Starter · #2 ·
Whoops! Slippsies!
Third line from bottom should read "oil should be better to lube the rear end than 85/90 oil".
Sorry!
Jay
 

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80/90 should be used ans since they are used gears there is no real reason to brake them in but if one is to brake them in drive the car around for about 15 minutes or so and let it cool down and repeat this a few times and new gears should never be towed with until they get around 500 miles on them.
 

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2.47 rear gears with a 289 and an automatic? You are going to have to change your name to "Jay67Slow". :) :)
 

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Discussion Starter · #7 ·
Mark,
Yeah, I do have a 9" rear in the car,but thanks for asking; that's the kind of mistake that could ruin your day!!!
jay67fast
 
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