JTDR with 373 Conversion to 488: Requires Entire Front Axle Changeout

[ShadowsPapa]

The prior generation of these axles DID require a carrier change. This version in the JT does not.
I have a chart that shows the break - assumed it was for these since the numbers were the same, but no, these don't require a carrier swap.
Maybe they are thinking of the other version or prior generation of this axle?

Supposedly this is for the pre-AdvanTec axles the JT has -

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[MOPAR Boy]

Heck, even the XR with its puny little 315X70R17’ is running 456. But, I digress.

I’m still not hearing from anyone who has done what I plan to do with all parameters the same, such as 2018+, which is an different animal than the pre 2018 axle.

 

[JTPatriot]

Heck, even the XR with its puny little 315X70R17’ is running 456. But, I digress.

I’m still not hearing from anyone who has done what I plan to do with all parameters the same, such as 2018+, which is an different animal than the pre 2018 axle.

I did in my previous post. I have a 2020 JTR. Only difference being mine is gas and yours is diesel. Front and rear axles are the same as yours. Mine where 4.10 and yours are 3.73. Regeared mine to 4.88.

 

[MOPAR Boy]

I did in my previous post. I have a 2020 JTR. Only difference being mine is gas and yours is diesel. Front and rear axles are the same as yours. Mine where 4.10 and yours are 3.73. Regeared mine to 4.88.

Thanks very much for all of this kind input, but going from 410 to 488 gearing is not the exact same scenario as going from 373 to 488. And, was this work done by an authorized Jeep dealer, using all Mopar parts? For full warranty protection, it appears I may have to change out my entire OEM front axle. For instance, what we don't know is perhaps the 488 will physically 'fit,' but is it spaced so close to the interior of the differential chassis that there could be heating issues, etc., or any number of other engineering considerations we may be unaware of?



Again, is there anyone here who has done exactly what I am about to do, so 2018+ M210 wide Dana 44 Advantec front axle, 373 to 488, diesel Rubicon, using all Mopar parts, plus exclusively using Jeep dealer labor, with full warranty protection, and you were OK’ed to just change the gear set from 373 to 488, along with the Mopar master install kit? If so, I will take that to my dealer, and see what gives.



Short of this, I can't just walk in there with other circumstances that seem quite similar, except for, x, y, and/or z details, let alone possibly not using all Mopar parts, nor exclusively using Jeep dealer labor, while protecting the factory Jeep warranty.



I hope someone has done exactly my scenario, and didn’t need a new 2018+ crate axle, as I'd love to tell my dealer about it, and go from there. My bet is my dealer would be glad to call that particular other Jeep dealer and discuss this scenario, and then do the same for me.

 

[ShadowsPapa]

I did in my previous post. I have a 2020 JTR. Only difference being mine is gas and yours is diesel. Front and rear axles are the same as yours. Mine where 4.10 and yours are 3.73. Regeared mine to 4.88.

To your point - doesn't matter if it starts out at 3.73 or 4.10, the housings are the same.
So I can't see how one could move from 4.10 to 4.88 but not 3.73 to 4.88

The carrier has always been the only real variable on these - and the axles used in the JT have a carrier that will handle these ratios.

 

[Chance575]

Ok start here




ok so you see how a differential works. You are replacing gears in it and bearings to new ones. You can reuse them but more than like will be damaged during removal. The gears will fit in any differential installed into a gladiator or no matter what model. You service writer is an idiot and doesn’t understand this.

 

[Kindafearless]

Thanks very much for all of this kind input, but going from 410 to 488 gearing is not the exact same scenario as going from 373 to 488. And, was this work done by an authorized Jeep dealer, using all Mopar parts? For full warranty protection, it appears I may have to change out my entire OEM front axle. For instance, what we don't know is perhaps the 488 will physically 'fit,' but is it spaced so close to the interior of the differential chassis that there could be heating issues, etc., or any number of other engineering considerations we may be unaware of?



Again, is there anyone here who has done exactly what I am about to do, so 2018+ M210 wide Dana 44 Advantec front axle, 373 to 488, diesel Rubicon, using all Mopar parts, plus exclusively using Jeep dealer labor, with full warranty protection, and you were OK’ed to just change the gear set from 373 to 488, along with the Mopar master install kit? If so, I will take that to my dealer, and see what gives.



Short of this, I can't just walk in there with other circumstances that seem quite similar, except for, x, y, and/or z details, let alone possibly not using all Mopar parts, nor exclusively using Jeep dealer labor, while protecting the factory Jeep warranty.



I hope someone has done exactly my scenario, and didn’t need a new 2018+ crate axle, as I'd love to tell my dealer about it, and go from there. My bet is my dealer would be glad to call that particular other Jeep dealer and discuss this scenario, and then do the same for me.

Everyone here is giving you solid advice...

If you don't want to take it, call another dealer and ask for a second opinion?

 

[Chance575]

And 4.56 are a better choice for your combination over 4.88. 4.88 are going to spin the motor at high rpms than your stock combination

 

[ShadowsPapa]

Bottom lines -
always use new bearings and seals.
Prior versions of these axle assemblies, and many other types of axles, DO require a carrier change because of the thickness difference in the ring gear to compensate for the pinion diameter change.
See the chart I posted earlier.
Carrier changes WERE required in the past. Not now.

The housing is not ever the catch - not in any differential I've worked on and swapped gears in or rebuilt for someone.

 

[Sekgunnut]

Everyone here is giving you solid advice...

If you don't want to take it, call another dealer and ask for a second opinion?

Being petty, prickish, and entitled is the new norm here. Too many wankers and sad cause it wasn’t this way until the last few months.

 

[rharr]

I want to go with 8.87 gears, will they fit in my jeep? Bigger numbers are better right? I don't care where in the RPM range the motor makes power, I just want big number! Now help me!

 

[NateKY]

No one is replying to your “exact” scenario because, well, your idea sucks. The right answer has been given multiple times. You just refuse to accept it.

 

[Larry D]

The prior generation of these axles DID require a carrier change. This version in the JT does not.
I have a chart that shows the break - assumed it was for these since the numbers were the same, but no, these don't require a carrier swap.
Maybe they are thinking of the other version or prior generation of this axle?

Supposedly this is for the pre-AdvanTec axles the JT has -

This

 

[FutureOdin]

Echoing what other folks have said here--my diesel cranks with 35s and 3.73s. Unless you're running 42s (which would require a stronger axle in general), I don't really see the benefit of 4.88s.

 

[ShadowsPapa]

Echoing what other folks have said here--my diesel cranks with 35s and 3.73s. Unless you're running 42s (which would require a stronger axle in general), I don't really see the benefit of 4.88s.

If I ran my gasser with 35s and the stock 3.73 gears, I'd never see 8th gear.

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