Any advantages for having a 741 differential case versus a 742 case?

440 PHIXX

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Bummed to see a 742? No crush sleeve in those.....and they have a good selection of gears to choose from.
I thought I read the 489 is stronger. I’m probably going to go with an S60 instead of trying to make an 8 3/4 last behind a 440 and a clutch.
 

moparmarks

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I'm running two 742 and one 489 cases. I like the 742 as they also usually came with the clutch type S/G as where the 489 came with the cone type. They are interchangeable though.
 

QuickBpBp

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Yup but someone else woke it up by giving me the red X so someone is reading through this stuff :D
Took 11 years for him to get up the courage to disagree with you!! :lol:
 

Cranky

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I'm running two 742 and one 489 cases. I like the 742 as they also usually came with the clutch type S/G as where the 489 came with the cone type. They are interchangeable though.
I used to sell the clutch types because they brought a lot more money and kept the cone units for me. I know how to make them work even when they ain't working when I get them. So long as the rest of the unit is in good shape, they can be made to work but then you have the idiots that will hammer on them thinking that it will finally lock up. Yeah, they will lock up eventually when the guts seize up and then it spits itself out the back of the housing lol. I caught my nephew doing that mess with his pickup and the guy is a certified mechanic!!
 

fesser

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This old thread is really starting to liven up.:popcorn2:
 

Crackedback

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I do love this old thread and the weak/strong BS that is sold to everyone.

None of the stuff regarding the pinion addresses the real weakness of the 8.75 units. But that suspect info sure drives the prices of certain cases up a lot. LOL

Reality is, one of them has the least amount of design flaws.
 

68-500

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I do love this old thread and the weak/strong BS that is sold to everyone.

None of the stuff regarding the pinion addresses the real weakness of the 8.75 units. But that suspect info sure drives the prices of certain cases up a lot. LOL

Reality is, one of them has the least amount of design flaws

Please enlighten us to the real weakness. Enquiring minds want to know.
 

Crackedback

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Dr Diff covers one reason the 741 is better. Never broke a 741 pinion. Had a couple 742 and 489 break right at the riser.

The other... ALL of the rears share the same ring gears and poor deflection characteristics/weak caps. None of which are be solved by a big pinion bearing.
 

68-500

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Dr Diff covers one reason the 741 is better. Never broke a 741 pinion. Had a couple 742 and 489 break right at the riser.

The other... ALL of the rears share the same ring gears and poor deflection characteristics/weak caps. None of which are be solved by a big pinion bearing.
Interesting. Thanks
 
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