6.4 Hemi Gear Swap

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U&A

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2k RPMs at 70mph. I would never considered 4.56 gears in a 14+ Hemi with 35s or 37s.

Are you not worried at all about how much less contact your pinion gear has with 5.13’s? Do you tow much?


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reloaderguy

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Are you not worried at all about how much less contact your pinion gear has with 5.13’s? Do you tow much?


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Have you seen a 5.13 R&P? I'm not worried.
 

U&A

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Im definitely going 4.88’s. It will work great for 35’s (most actually 34.8”) as well as my current tires 285/75/18 toyo mt (35.1”) or the 315/70/18 toyo mt’s (35.7”) that i May switch to.

This thread is VERY helpful. Thank you to all the contributors.

how many of you went to (or want to go to) a limited slip carrier the front ( like the Detroit true trac)? Iv considerd it but can not pony up an additional almost $1000 for it.


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14RAM4X4

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Just Differentials. AAM 11.5 and Yukon GM 9.25. Yukon 9.25 spacer and ring gear bolts.

5.13s are perfect for 14+ Hemi trucks with 37s.

Wish you were near South Texas. I'd love to give your truck a test drive. Looking to swap gears next month if I can swing it. 2 quotes so far. $2600 & $2900 with Nitro kit. I'm gonna request a re-quote from both shops with AAM & Yukon gears you posted above ("Just Differentials. AAM 11.5 and Yukon GM 9.25. Yukon 9.25 spacer and ring gear bolts.") and see if it brings the price down any.

@reloaderguy , thanks for all your input in the multiple gear swap threads. You and others have been a wealth of knowledge. Maybe there should be a stickied thread for gear swaps. Only posts are from those that have done a gear swap. I think it would REALLY help those researching and looking into getting it done. It may keep the HD area a little less cluttered because it would reduce gear threads from popping up every few months.

If I get my gears done next month, I'll try to start a thread about my experience.

Something like:

Year:
Model / 4x4 or 2wd:
Trans:
Tire Size:
Front R&P Gear Ratio & Brand:
Rear R&P Gear Ratio & Brand:

Parts List with Part #s:
Approximate out the door cost:
Shop name, Location, recommend to others:
Special Note
: (ex: Ring gear spacer required for front diff, part#
-or- new carrier required for front diff, etc)
Other performance mods: ex: intake, exhaust, programmer, etc
Observations / comments: ex: RPM at "x" speed, responsiveness, towing, gear whine or lack of, etc.
 

reloaderguy

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If you go with AAM 5.13 rear gears make sure to tell the installer you need conversion bearings. Also, the crush sleeve may need to be shortened. My advice is to use a shop that has done the Ram 9.25/11.5 swap before and has access to a machine shop.

I've done a few long road trips at this point and can comment on fuel economy, 4.10 to 5.13 comparison. Around town I gained two MPG. On the highway, 70mph and slower mileage stayed the same. 75mph and up I lost one MPG. The truck drives effortlessly and holds 6th gear up grades.
 
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BOB RAM 2500

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SUPERBEEMIKE ... You have made my final decision... Looking to buy a 5th wheel in the 14k weight range .... 3.73's just are not working for me now with my truck camper and boat ... 4.56 will be perfect, I hope ... Your link to search for the driveline shop does not show anything for my area here in middle Florida ... Now to find someone I can trust ... And many thanks for all the information this post has provided.
 

rammerrodder

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does anyone from southern wisconsin know of a reputable place that does gear swaps? not a lot of information out there.
 

GsRAM

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If you go with AAM 5.13 rear gears make sure to tell the installer you need conversion bearings. Also, the crush sleeve may need to be shortened. My advice is to use a shop that has done the Ram 9.25/11.5 swap before and has access to a machine shop.

I've done a few long road trips at this point and can comment on fuel economy, 4.10 to 5.13 comparison. Around town I gained two MPG. On the highway, 70mph and slower mileage stayed the same. 75mph and up I lost one MPG. The truck drives effortlessly and holds 6th gear up grades.


This is excellent info, thanks for sharing and confirms. My thoughts. My truck does not see the highway very often and when it does only for brief periods and no more than 74 mph...if I ever do this I'm now thinking 4.56s for my stock tires would be a huge improvement over my 3.73s...do that and then a tune to get rid of the stupid mds and I'd be set
 

RAM_Designs

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This is excellent info, thanks for sharing and confirms. My thoughts. My truck does not see the highway very often and when it does only for brief periods and no more than 74 mph...if I ever do this I'm now thinking 4.56s for my stock tires would be a huge improvement over my 3.73s...do that and then a tune to get rid of the stupid mds and I'd be set
4.56's with stock tire size would be great. Imagine how I feel with the 3.73's and 37's haha.
 

GsRAM

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4.56's with stock tire size would be great. Imagine how I feel with the 3.73's and 37's haha.


Yeah I'm sure she's lacking some punch with the 73s with a 37" tire no doubt
 

U&A

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SUPERBEEMIKE ... You have made my final decision... Looking to buy a 5th wheel in the 14k weight range .... 3.73's just are not working for me now with my truck camper and boat ... 4.56 will be perfect, I hope ... Your link to search for the driveline shop does not show anything for my area here in middle Florida ... Now to find someone I can trust ... And many thanks for all the information this post has provided.

JMO,

I have 4.88’s with 35’s. If you are planning on towing 14k with stock tires.... get 4.88’s. If you are planning on towing that much with 35’s.... get 5.13’s

I frequently tow 4,000-7,000 my truck does well but I would absolutely want 5.13’s if towing 8,000 or more all the time

Not going to lie. I wish i went 5.13’s with 35’s. But its not really necessary unless you are frequently towing. I wanted to go up to 315/70/18 toyo mt’s that measure 35.7”x13” but im not going to. I would want 5.13’s for sure.


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Mountaineer83

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I just towed my 42' 5th wheel from Georgia back to West Virginia this past weekend. My dry weight it around 13,400, so probably close to maxed out with all the junk I had from living in it the past year. (I'm not here to start any weight rating posts, just giving a real world account)

Now, I kept my speed around 60-65 mph as I feel that is fast enough with a large trailer in tow. I have 4.10s and it did relatively well for a large gas engine. I only shifted to 2nd when I got into West Virginia on a few larger hills along I-77. Overall she did great.

So with that said, I think with 4.88s in the future, I will be in the trucks sweet spot for towing. It would hum right along in 3rd on a lot of the hills now. I was actually pleased overall with the performance. I did notice a difference though when I switched to 93 octane fuel while towing. Much better sounding and happy Hemi!
 

RAM-pagingMN

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does anyone from southern wisconsin know of a reputable place that does gear swaps? not a lot of information out there.

not southern wisconsin, but 4X4 unlimited in Elgin, MN will do it for about $1000 bucks! thats install only. Ask for Jim Hoeft, they build crazy offroad and Drag Jeeps!
 

Ratket

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^ Good report, people need to remember that the terrain we all drive in Varys hugely, when I had my 6.4- the mtn passes I crossed repeditly ranged from 5k feet to 7k feet. A diesel would of been better suited but a gas motor with proper gearing “ Not the two crummy sets offers by the manufacture” would of made all the difference.
 

GsRAM

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not southern wisconsin, but 4X4 unlimited in Elgin, MN will do it for about $1000 bucks! thats install only. Ask for Jim Hoeft, they build crazy offroad and Drag Jeeps!


Is that for both axles? Labor only or labor and parts? Assuming labor only. Thats a great price if it's for both axles
 

GsRAM

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Install only, so I'm assuming you have to supply the parts.
Even so that's a great price! Could probably get the entire job done for under 2k which is great
 
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