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89 MJ hp30 or lp30??


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I was browsing at Randy's R&P's website and they list my front axle as a standard rotation axle. It looks like a high pinion to me and everything else I have read says high pinion. I have an XJ and I compared the axles... they look the same to me. Which one came stock in an 89 MJ 4.0?

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I was browsing at Randy's R&P's website and they list my front axle as a standard rotation axle. It looks like a high pinion to me and everything else I have read says high pinion. I have an XJ and I compared the axles... they look the same to me. Which one came stock in an 89 MJ 4.0?

 

 

Its HP.

 

But please, no 'standard rotation' or 'reverse rotation' talk! It's just wrong! Reverse rotation axles actually drive the other direction, and there isn't many of them out there (think prior to 1950). Reverse cut, reverse crown, reverse spiral, high pinion, and HP are all commonly accepted terms and are at least reasonably correct.

 

(sorry to rant, it just bugs me)

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I was browsing at Randy's R&P's website and they list my front axle as a standard rotation axle. It looks like a high pinion to me and everything else I have read says high pinion. I have an XJ and I compared the axles... they look the same to me. Which one came stock in an 89 MJ 4.0?

 

 

Its HP.

 

But please, no 'standard rotation' or 'reverse rotation' talk! It's just wrong! Reverse rotation axles actually drive the other direction, and there isn't many of them out there (think prior to 1950). Reverse cut, reverse crown, reverse spiral, high pinion, and HP are all commonly accepted terms and are at least reasonably correct.

 

(sorry to rant, it just bugs me)

It's all terminology. I have one friend who refers to ALL axles as "rears," even when used in the front. And that's how the term "reverse rotation" came about. Put a rear diff in the front, and when the vehicle is going forward the ring gear spins in the reverse of the direction it would in the rear. Hence, "Reverse rotation."

 

Obviously, if it's literally a rear axle that's flipped and put in the front, that also means the teeth are engaging on the "coast" side rather than the "drive" side. So the manufacturers started making "reverse cut" or "reverse bevel" gearsets so that gears rotating in the reverse direction would still be engaging on the strong side.

 

High and low pinion actually are unrelated to direction of rotation. What happens, though, is if a rear is low pinion and you just put it in the front, it rotates in reverse. So then if you flip it over so the pinion sits high, it magically rotates in the correct direction again. Without reverse cut gears. Reverse bevel gears are necessary when using a low pinion axle in the front.

 

At least, I think that's how it works. It's been awhile since I've thought about all that, so I may have gotten myself confused.

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I was browsing at Randy's R&P's website and they list my front axle as a standard rotation axle. It looks like a high pinion to me and everything else I have read says high pinion. I have an XJ and I compared the axles... they look the same to me. Which one came stock in an 89 MJ 4.0?

 

 

Its HP.

 

But please, no 'standard rotation' or 'reverse rotation' talk! It's just wrong! Reverse rotation axles actually drive the other direction, and there isn't many of them out there (think prior to 1950). Reverse cut, reverse crown, reverse spiral, high pinion, and HP are all commonly accepted terms and are at least reasonably correct.

 

(sorry to rant, it just bugs me)

Talk to Randy at Randys Ring and Pinion about that complaint :D
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I was browsing at Randy's R&P's website and they list my front axle as a standard rotation axle. It looks like a high pinion to me and everything else I have read says high pinion. I have an XJ and I compared the axles... they look the same to me. Which one came stock in an 89 MJ 4.0?

 

 

Its HP.

 

But please, no 'standard rotation' or 'reverse rotation' talk! It's just wrong! Reverse rotation axles actually drive the other direction, and there isn't many of them out there (think prior to 1950). Reverse cut, reverse crown, reverse spiral, high pinion, and HP are all commonly accepted terms and are at least reasonably correct.

 

(sorry to rant, it just bugs me)

It's all terminology. I have one friend who refers to ALL axles as "rears," even when used in the front. And that's how the term "reverse rotation" came about. Put a rear diff in the front, and when the vehicle is going forward the ring gear spins in the reverse of the direction it would in the rear. Hence, "Reverse rotation."

 

Obviously, if it's literally a rear axle that's flipped and put in the front, that also means the teeth are engaging on the "coast" side rather than the "drive" side. So the manufacturers started making "reverse cut" or "reverse bevel" gearsets so that gears rotating in the reverse direction would still be engaging on the strong side.

 

High and low pinion actually are unrelated to direction of rotation. What happens, though, is if a rear is low pinion and you just put it in the front, it rotates in reverse. So then if you flip it over so the pinion sits high, it magically rotates in the correct direction again. Without reverse cut gears. Reverse bevel gears are necessary when using a low pinion axle in the front.

 

At least, I think that's how it works. It's been awhile since I've thought about all that, so I may have gotten myself confused.

 

 

Yes, high and low pinion having nothing to do with rotation. Hence nobody should call a HP axle reverse rotation.

 

But I have no idea what you're talking about otherwise. I'm a little drunk. But I know this. Take a rear D44 and install it in the front of your truck and it'll drive the right direction (other than a few driveshaft and steering issues). Take a HP front D44 and throw it in the rear and it'll drive the right direction.

 

It will however ride the 'wrong' (coast) side of the gears doing either of the above mention situations, given you're on the power moving the vehicle forewards.

 

I have no idea if you're agreeing with me or not, or if I'm agreeing with you. Stupid cheap beer.

 

 

And randy's website is retarded. Talk to dana. They call HP 'reverse crown'.

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Entertainment courtesy of Randy's R&P

 

Their motto should be "We know our gears, we just don't know which way they rotate!" :D or something to that effect... lol

 

Has anybody else went there and seen what I was talking about?

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Entertainment courtesy of Randy's R&P

 

Their motto should be "We know our gears, we just don't know which way they rotate!" :D or something to that effect... lol

 

Has anybody else went there and seen what I was talking about?

Personally, I would buy from Randy's only if every other source in the country went out of business. I can't point to any reason why -- I've never bought from them so I can't say they've done me dirty. I just don't get good vibes from the whole operation.

 

I used to like Drive Train Direct -- are they still around?

 

Reider Racing is another good source.

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