Thoughts on a regear with 37s?

[crazy jerry]

yes, if memory serves me right a spacer is needed. One of the axles is a bit “tricky”, needing a spacer and GM gears. I think its the front.

really theres nothing tricky about a spacer. its just to compensate for a difference in carrier and/or ring gear difference

 

[olyelr]

really theres nothing tricky about a spacer. its just to compensate for a difference in carrier and/or ring gear difference

Yea, Im not really sure. But I have read up enough about people regearing these newer axles, and one of them is odd for some reason.

 

[hbleconey]

so I confirmed today that the front axle is 9.25 and the rear is 11.5 from mopar. Nitro has this to say so i'm working on getting him some more info. Making a little progress but i think the dream of finding anything that will be covered by the warranty is slim to none

"We have had some problems with 2019's where the rear pinion is 34-spline and our gears (or any aftermarket gears) will not fit the yoke. Those setups also have 16-bolt ring gears and the standard 11.5 has 12 bolts. If you can get me the exact size of the pinion nut I can tell you if our kit will work. You will need to drop the back of the rear driveshaft to get to the not to measure it."

 

[WY.Ram]

sounds like given you're altitude you would have gone with 5.29 in retrospec? i'm at sea level in CA so assuming eventually when i figure this out 5.13 will be sufficient

Absolutely, That is where I'm sitting with it. 5.13 at sea level? Will be not only sufficient but bad ass. I get all giddy and grin'n just thinking about sea level.

Keep after it. Looks like it's not getting any easier but it'll be worth it.

'16 PWagon with a badass Greene tune feed'n & Fire'n 6.4L 6spd // 5.13 AAM // 37" KM3, -24mm // DOR, Purple Cranium // CAI, ARH, Solo Mach44 // z36, EBC // Custom Graphics, AVS, 4% VLT // Morimoto, Rigid, Diode Dynamics // Alfa, Diablo //.................

 

[BoldAdventure]

The deeper you go, the smaller the pinon gets. 5.13's do add a bit of grunt, but don't tow heavy, your pinion is a lot weaker if you've ever looked at 4.88 and 5.13 side by side.

 

[crazy jerry]

The deeper you go, the smaller the pinon gets. 5.13's do add a bit of grunt, but don't tow heavy, your pinion is a lot weaker if you've ever looked at 4.88 and 5.13 side by side.

ah ya the age old pinion head size debate. its been beat to death since time began. alot of bad info and urban legend out there. plenty of well qaulified experts certainly wouldnt agree with your statement. theres alot of variables when comparing one gear set to another

just one of probly thousands of bits of info

Its sort of complicated to pick the best ratio based on strength. In the end, they are all acceptable designs per the manufacturer, or they wouldn't make them, and the better the quality of that manufacturer, the better the quality of the gears for which you will pay more.
The thing to remember is the ring gear diameter is constant; it never changes. Because of this, no matter how many teeth are on the pinion, the mean diameter of the pinion will always be smaller than the next numerically lower gear set for the same model axle. Because the ring gear diameter is constant, to get a lower gear ratio with the same number of teeth on the pinion, they must place more teeth in the same mean circumference on the ring gear, which makes the size of the teeth smaller, and therefore their contact area smaller. At some point, the designers feel the teeth on the ring gear are getting too small for sufficient contact, so they reduce the number of teeth on the pinion so they can reduce the number of teeth on the ring gear. Since the mean diameter of the pinion is selective, they are at liberty to make the tooth depth as deep as the pitch will allow, thus keeping the pinion teeth relatively strong. As was stated, the lower the gear ratio, the less force that is realized by the pinion under the same set of circumstances, but the actual strength of the pinion gear due to its smaller diameter versus how much less force it sees is the variable that needs to be determined. The other thing to off-set these factors is actual strength of the gear teeth based on pressure as determined by the actual contact area and how much of how many teeth it can be spread across as it turns. This pressure increases per square inch as the number of teeth on the ring gear increase due to the ring gear teeth getting smaller, regardless of pinion diameter, tooth depth or number of pinion teeth. Its the actual size of the ring gear teeth that determine how large and at what pitch their contact area can be, which I'm sure is used to its maximum by the gear's design

 

[WY.Ram]

ah ya the age old pinion head size debate. its been beat to death since time began. alot of bad info and urban legend out there. plenty of well qaulified experts certainly wouldnt agree with your statement. theres alot of variables when comparing one gear set to another

just one of probly thousands of bits of info

Its sort of complicated to pick the best ratio based on strength. In the end, they are all acceptable designs per the manufacturer, or they wouldn't make them, and the better the quality of that manufacturer, the better the quality of the gears for which you will pay more.
The thing to remember is the ring gear diameter is constant; it never changes. Because of this, no matter how many teeth are on the pinion, the mean diameter of the pinion will always be smaller than the next numerically lower gear set for the same model axle. Because the ring gear diameter is constant, to get a lower gear ratio with the same number of teeth on the pinion, they must place more teeth in the same mean circumference on the ring gear, which makes the size of the teeth smaller, and therefore their contact area smaller. At some point, the designers feel the teeth on the ring gear are getting too small for sufficient contact, so they reduce the number of teeth on the pinion so they can reduce the number of teeth on the ring gear. Since the mean diameter of the pinion is selective, they are at liberty to make the tooth depth as deep as the pitch will allow, thus keeping the pinion teeth relatively strong. As was stated, the lower the gear ratio, the less force that is realized by the pinion under the same set of circumstances, but the actual strength of the pinion gear due to its smaller diameter versus how much less force it sees is the variable that needs to be determined. The other thing to off-set these factors is actual strength of the gear teeth based on pressure as determined by the actual contact area and how much of how many teeth it can be spread across as it turns. This pressure increases per square inch as the number of teeth on the ring gear increase due to the ring gear teeth getting smaller, regardless of pinion diameter, tooth depth or number of pinion teeth. Its the actual size of the ring gear teeth that determine how large and at what pitch their contact area can be, which I'm sure is used to its maximum by the gear's design

Damn dawg, glad I didn't have to write that, but I couldn't agree more.

And let me just add, I pound on mine. I take what I consider to be excellent care of my truck, but if my diffs were weak they would have done imploded by now, that I guarantee.

Slap a Nissan sticker on it and call it "good as new" while I drag it to the scrap pile. Ha, Not.

Nope, I have given her the full pull for 40k miles since and never so much as a peep from these diffs. I have had them both open twice since, beautiful! They will not be the next upgrade/repair on my truck. I even wrapped em in Spyder legs I like em so much!

'16 PWagon with a badass Greene tune feed'n & Fire'n 6.4L 6spd // 5.13 AAM // 37" KM3, -24mm // DOR, Purple Cranium // CAI, ARH, Solo Mach44 // z36, EBC // Custom Graphics, AVS, 4% VLT // Morimoto, Rigid, Diode Dynamics // Alfa, Diablo //.................

 

[olyelr]

Yea, the smaller pinion may be weaker, but it shouldn't be too weak to do its job (or they wouldn't make it).

 

[BoldAdventure]

ah ya the age old pinion head size debate. its been beat to death since time began. alot of bad info and urban legend out there. plenty of well qaulified experts certainly wouldnt agree with your statement. theres alot of variables when comparing one gear set to another

just one of probly thousands of bits of info

Its sort of complicated to pick the best ratio based on strength. In the end, they are all acceptable designs per the manufacturer, or they wouldn't make them, and the better the quality of that manufacturer, the better the quality of the gears for which you will pay more.
The thing to remember is the ring gear diameter is constant; it never changes. Because of this, no matter how many teeth are on the pinion, the mean diameter of the pinion will always be smaller than the next numerically lower gear set for the same model axle. Because the ring gear diameter is constant, to get a lower gear ratio with the same number of teeth on the pinion, they must place more teeth in the same mean circumference on the ring gear, which makes the size of the teeth smaller, and therefore their contact area smaller. At some point, the designers feel the teeth on the ring gear are getting too small for sufficient contact, so they reduce the number of teeth on the pinion so they can reduce the number of teeth on the ring gear. Since the mean diameter of the pinion is selective, they are at liberty to make the tooth depth as deep as the pitch will allow, thus keeping the pinion teeth relatively strong. As was stated, the lower the gear ratio, the less force that is realized by the pinion under the same set of circumstances, but the actual strength of the pinion gear due to its smaller diameter versus how much less force it sees is the variable that needs to be determined. The other thing to off-set these factors is actual strength of the gear teeth based on pressure as determined by the actual contact area and how much of how many teeth it can be spread across as it turns. This pressure increases per square inch as the number of teeth on the ring gear increase due to the ring gear teeth getting smaller, regardless of pinion diameter, tooth depth or number of pinion teeth. Its the actual size of the ring gear teeth that determine how large and at what pitch their contact area can be, which I'm sure is used to its maximum by the gear's design

LOLOLOLZ

Thanks for the laughs.

 

[Blue Streak]

I'm still trying to have 5.13s installed in my '17 PW. Using AAM part #40136007 for the front & #40030646 for the rear. Of you guys that have had this done, are there any extra or odd parts needed to install? Ring gear spacer in the front? Does the pinion bushing in the rear have to be replaced to comp for the new pinion possibly being smaller as my mechanic has told me? Or is this a straight forward install? We need to have ALL parts neccessary on hand with no surprises to do this. Looking for first hand info only please.

 

[WY.Ram]

I'm still trying to have 5.13s installed in my '17 PW. Using AAM part #40136007 for the front & #40030646 for the rear. Of you guys that have had this done, are there any extra or odd parts needed to install? Ring gear spacer in the front? Does the pinion bushing in the rear have to be replaced to comp for the new pinion possibly being smaller as my mechanic has told me? Or is this a straight forward install? We need to have ALL parts neccessary on hand with no surprises to do this. Looking for first hand info only please.

I wasn't the mechanic but I did pay for the parts, i can confirm there was an "install kit" that was needed for my truck. I also thought it came with the one if the gear sets. The main component was a spacer / shim for the ring gear, ok that's where it all stops for me, coulda been for the pinion, lol.
There was a kit, the tech shrugged it off like it was common and not really too special. He did use the spacer for the install and said it was necessary.
I still have my paper work, I'll go did it up and see if it was itemized and get back asap with any available info.
Axle dude gave a 12 month unlimited mileage warranty, I would think some receipt detail is warranted.
In case my b wife drowns me in the septic (neighbors septic, she already said) before I get back here is the shop that did mine. Two guys work there, the owner who answers the phone and a top tech who doesn't.

Colorado Axle and Gear
303-286-0338

5-star rating on Google w 73 and 5-star on Facebook w 15, that is impressive.

'16 PWagon with a badass Greene tune feed'n & Fire'n 6.4L 6spd // 5.13 AAM // 37" KM3, -24mm // DOR, Purple Cranium // CAI, ARH, Solo Mach44 // z36, EBC // Custom Graphics, AVS, 4% VLT // Morimoto, Rigid, Diode Dynamics // Alfa, Diablo //.................

 

[WY.Ram]

I have only perpetuated the myth, I didn't put eyes or hands on any such install kit, and it is not listed on my copy of the bill.
I'll share it any way for what is listed and their contact info, sorry man.

'16 PWagon with a badass Greene tune feed'n & Fire'n 6.4L 6spd // 5.13 AAM // 37" KM3, -24mm // DOR, Purple Cranium // CAI, ARH, Solo Mach44 // z36, EBC // Custom Graphics, AVS, 4% VLT // Morimoto, Rigid, Diode Dynamics // Alfa, Diablo //.................

 

[crazy jerry]

LOLOLOLZ

Thanks for the laughs.

nobodys trying to pull a d9 cat or do 6000rpm launches at a drag strip. books will also say dont use a spacer but again we arent sled pulling or drag racing .

 

[62Blazer]

You typically buy an install kit with swapping gears, not because it has special parts to accommodate different gear ratios but rather there are some small parts that are not reusable...or it's easier to have new parts versus removing them from the old parts. There are minor and major install kits. Typically the minor kits will have shims, seals, and smaller misc. parts where as the major kits will have new bearings included.

It was mentioned above, but as the gears get lower (higher numerically) the pinion gear will get smaller. This effectively puts it further away from the ring gear. A lot of differentials have what you refer to as carrier splits (the carrier is the actual differential...open diff, limited slip, locker, etc...). Once the gears reach a certain ratio they have a carrier machined differently so it moves the ring gear closer to the pinion. This has a lot of do with cost as it's often cheaper to make a new cast carrier versus machining a ring gear thicker that is made from high dollar steel. Many companies make a spacer you can used instead of getting a new carrier. On a Power Wagon, going from 4.10 to 5.13 means you either need a spacer or you would have to replace the entire front locker assembly (big $$). Nothing tricky about a spacer, and not sure what is meant by "GM gears"....the axles are made by AAM.

 

[olyelr]

You typically buy an install kit with swapping gears, not because it has special parts to accommodate different gear ratios but rather there are some small parts that are either not reusable...or it's easier to have new parts versus removing them from the old parts. There are minor and major install kits. Typically the minor kits will have shims, seals, and smaller misc. parts where as the major kits will have new bearings included.

It was mentioned above, but as the gears get lower (higher numerically) the pinion gear will get smaller. This effectively puts it further away from the ring gear. A lot of differentials have what you refer to as carrier splits (the carrier is the actual differential...open diff, limited slip, locker, etc...). Once the gears reach a certain ratio they have a carrier machined differently so it moves the ring gear closer to the pinion. This has a lot of do with cost as it's often cheaper to make a new cast carrier versus machining a ring gear thicker that is made from high dollar steel. Many companies make a spacer you can used instead of getting a new carrier. On a Power Wagon, going from 4.10 to 5.13 means you either need a spacer or you would have to replace the entire front locker assembly (big $$). Nothing tricky about a spacer, and not sure what is meant by "GM gears"....the axles are made by AAM.

I think what guys are finding out is the part number(s) for the some of the parts used are for a GM truck.

 

[Hammer757]

When you regear do you need to update the computer? I wasn't sure if the computer needed the gear ratio like it wants the tire info.

 

[WhiteExpress]

When you regear do you need to update the computer? I wasn't sure if the computer needed the gear ratio like it wants the tire info.

Shouldn't. Truck reads a tone ring on the ring gear. One rotation is one rotation.

 

[Hammer757]

I spoke with AEV and they said with 37" tires they just run the 4.10 gears. When they go to 40's they use the 5.13 gears. Just passing the info along.

 

[donivan]

I spoke with AEV and they said with 37" tires they just run the 4.10 gears. When they go to 40's they use the 5.13 gears. Just passing the info along.

Was this for the gas engine or diesel? I recall they were putting 4.30 in Diesel engines with 40s.

Anyone running 4.10s with 37s with an 8 speed and feel you need to regear?

 

[Hammer757]

Was this for the gas engine or diesel? I recall they were putting 4.30 in Diesel engines with 40s.

Anyone running 4.10s with 37s with an 8 speed and feel you need to regear?

This was for a 5th gen PowerWagon so would be the 6.4 gas.