Gear swap. Check my pattern please.

[fat_head]

Would you call this good?

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[chevymitchell]

Would you call this good?

It's set a hair to the performance side, but not enough to matter. You'll be good to go with this.

 

[Headbarcode]

It's set a hair to the performance side, but not enough to matter. You'll be good to go with this.

If you don't mind elaborating on this, I'd be very interested in learning something new. I've replaced damaged diff parts in commercial vehicles, but was never in the performance sector of mechanics.

Thanks buddy!

 

[chevymitchell]

If you don't mind elaborating on this, I'd be very interested in learning something new. I've replaced damaged diff parts in commercial vehicles, but was never in the performance sector of mechanics.

Thanks buddy!

Edited to remove the ratio and rpm references. Added picture of a performance pattern from a standard pattern chart:

Any pattern set to the inside of the ring circumference (center of teeth) would effectively be a performance (competition) set up. Under high levels of torque, the pinion is trying to unscrew itself from the housing. The torque applied is trying to do this, but the housing is much stronger, so the torque goes to move the tires instead. When you launch a drag car or equivalent high performance vehicle, this torque can distort the ring, pinion, and housing. This distortion under a performance setup would allow the pinion to move to the center of the ring teeth where it’s strongest. All that metal in there doesn’t just stay put under load. More load, more distortion. Any ring and pinion set more to the economy side (outside of center) would do well, but in a performance environment, the pinion would move further to outside of the ring. Higher risk of breaking the gear teeth. With all that said, none of these Jeeps produce that much power - normally, BUT when you’re in 4LO, that torque is absolutely distorting things. That’s why it’s best to have gears set up center or very slightly off from center.

It’s not always about keeping gears from making noise. It’s a matter of how you use the vehicle and load. The idea is to keep the pinion in the center and have enough backlash to use the oil.

 

[Headbarcode]

Any pattern set to the inside of the ring circumference (center of teeth) would effectively be a performance set up. The gear ratio is provided you have everything set perfect on zero. If you’re set inside of center, then you would make your ratio a hair smaller. You’ll end up at 4.85 or 4.86, for example. Also, under high levels of torque, the pinion is trying to unscrew itself from the housing. The torque applied is trying to do this, but the housing is much stronger, so the torque goes to move the tires instead. When you launch a drag car or equivalent high performance vehicle, this torque can distort the ring, pinion, and housing. This distortion under a performance setup would allow the pinion to move to the center of the ring teeth where it’s strongest and the ratio is the most accurate. All that metal in there doesn’t just stay put under load. More load, more distortion. Any ring and pinion set more to the economy side (outside of center) would do well, but in a performance environment, the pinion would move further to outside of the ring. Higher risk of breaking the gear teeth. With all that said, none of these Jeeps produce that much power - normally, BUT when you’re in 4LO, that torque is absolutely distorting things. That’s why it’s best to have gears set up center or very slightly off from center.

It’s not always about keeping gears from making noise. It’s a matter of how you use the vehicle and load.

Awesome explanation that made for a spot on mental picture! Thanks a bunch! I've only ever set engagement depth via a dial indicator on the ring gear teeth. I had no idea that location benefits along the circumference was even a thing. Thanks again for the schooling!

 

[JAY1941]

Any pattern set to the inside of the ring circumference (center of teeth) would effectively be a performance set up. The gear ratio is provided you have everything set perfect on zero. If you’re set inside of center, then you would make your ratio a hair smaller. You’ll end up at 4.89 or 4.90, for example. Also, under high levels of torque, the pinion is trying to unscrew itself from the housing. The torque applied is trying to do this, but the housing is much stronger, so the torque goes to move the tires instead. When you launch a drag car or equivalent high performance vehicle, this torque can distort the ring, pinion, and housing. This distortion under a performance setup would allow the pinion to move to the center of the ring teeth where it’s strongest and the ratio is the most accurate. All that metal in there doesn’t just stay put under load. More load, more distortion. Any ring and pinion set more to the economy side (outside of center) would do well, but in a performance environment, the pinion would move further to outside of the ring. Higher risk of breaking the gear teeth. With all that said, none of these Jeeps produce that much power - normally, BUT when you’re in 4LO, that torque is absolutely distorting things. That’s why it’s best to have gears set up center or very slightly off from center.

It’s not always about keeping gears from making noise. It’s a matter of how you use the vehicle and load.

This is exactly why I started building my Jeep. Because of aftermarket support and people like you who are in the game of changing things around. Thanks for the explanation.

 

[chevymitchell]

This is exactly why I started building my Jeep. Because of aftermarket support and people like you who are in the game of changing things around. Thanks for the explanation.

I'm happy to help; they're all just big legos.

 

[fat_head]

Here's a pro-tip from not-a-pro: when you get it all put back together then wonder why it's leaving a pool of 75w140 under your Jeep, make sure you didn't forget to put this back on

 

[AnnDee4444]

If you’re set inside of center, then you would make your ratio a hair smaller. You’ll end up at 4.89 or 4.90, for example.

This part doesn't sound quite right... If it was a CVT then I would agree, but a toothed gear is always going to be dictated by the number of teeth, regardless of their relative position. Moving the gears closer or further away isn't going to change the ratios between them.

 

[chevymitchell]

This part doesn't sound quite right... If it was a CVT then I would agree, but a toothed gear is always going to be dictated by the number of teeth, regardless of their relative position. Moving the gears closer or further away isn't going to change the ratios between them.

Yes, you are correct. I was just trying to paint a picture.

I went ahead and just removed the reference to both ratio and RPM and just kept the info correct for answering the "performance" question. Thanks man.

 

[AnnDee4444]

Since we're nerding-out on gears, I ran into this interesting scenario a while back:

The Honda S2000 (front engine, rear-wheel drive, 6-speed manual transmission) has a secondary gear reduction after the 1-6 gearsets, but still located in the transmission housing (tail-shaft would be the closest equivalent). This effects the final drive, with the first & second generations of S2000s having different ratios.

There is an aftermarket company that sells a kit that replaces one of the reduction gears, and it meshes with the factory gear. The spacing between the gears is fixed and not changeable. I guess there is enough play in the gearset that they were able to design a gear with roughly the same diameter but removed one tooth, therefore altering the ratio.

 

[grimmjeeper]

This part doesn't sound quite right... If it was a CVT then I would agree, but a toothed gear is always going to be dictated by the number of teeth, regardless of their relative position. Moving the gears closer or further away isn't going to change the ratios between them.

It's really the other way around.

The number of teeth on the two gears, along with a fixed diameter ring gear, determines the diameter of the pinion head.

 

[MARSHMELLA]

I like turtles

 

[chevymitchell]

It's really the other way around.

The number of teeth on the two gears, along with a fixed diameter ring gear, determines the diameter of the pinion head.

Yes… if you’re anywhere off of center of the ring gear, it will change. I wasn’t going to go any deeper on this because the pinion really should be set on zero, give or take, and it gets into a calculus problem in order to explain it further out side of center on the ring gear. For all intents and purposes, a properly set ring and pinion, should be as close to zero as possible for these Jeeps. What you’re saying is pinion depth changes backlash and that’s about as simple as one can make it without sounding too nerdy. Lol.

 

[chevymitchell]

I like turtles

We would be good friends. Lol

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