Dodge Cummins Diesel Forum banner

21 - 36 of 36 Posts

·
Registered
Joined
·
844 Posts
My '17 with the Aisin and 20" factory wheels has 3.42 because it is SRW. I see now on the '19s you have a choice again. I pull a 39 foot 5'er @ about 16k pounds. I haven't noticed an issue yet, but I also haven't towed it anywhere but the plains so I haven't challenged the truck on any mountain grades (yet). Would a move to 4.11 be advised/beneficial to me?
I think the Aisin has a lower ratio in the transmission. If you feel ok towing with your truck stock, I'm sure it's fine. Tons of guys here towing with stock gears. I'm on 35's so my issue is that I reduced my ratio even further by having slightly larger tires. Additionally, I had 37's and 4.56's on my 2010, which to me was the perfect ratio, as I used my truck for primarily towing.
 

·
Registered
Joined
·
30 Posts
Discussion Starter #22
I also re-geared for my 35's so that I could better pull a loaded hay trailer, and just generally go easier on the transmission. I went with Yukon 4.11's in my truck, and love the way it pulls. Just hauled a load of steel pipe, about 14k pounds, back for 3.5 hours and it was a night and day difference. Never did the truck feel like I had to put my foot down to climb a hill, and starting from a dead stop felt so much better on the transmission.

I don't think the change from 3.42's would justify the price of re-gearing. I can try to send you a video of how it shifts and goes through the gears with the 4.11's if you're curious, but personally, that's exactly how a cummins was designed to be run. Remember also that any big hills you go up, you will have to go down as well, and the exhaust brake is much more effective with the new gearing as well.

An additional point to be made, but with the Yukon gears, you will need a new carrier for the front that has a different deck height. I called Randy's to verify when I did my install as I wasn't sure if the shop was trying to pull a quick one, but they validated. You may want to check and see if AAM gears require the same thing, as if they do not, that will save you about $400 versus my Yukon install.



Let me know.
I just got off the phone with Randy's, and they assured me that the front set will not need a new carrier. But thanks for the heads up, I already have the gears, and am scheduled for install next week.

Interesting thing though. The rear set is made in the USA, the front set in China. Both have the same warranty.
 

·
Registered
Joined
·
844 Posts
I just got off the phone with Randy's, and they assured me that the front set will not need a new carrier. But thanks for the heads up, I already have the gears, and am scheduled for install next week.

Interesting thing though. The rear set is made in the USA, the front set in China. Both have the same warranty.
Well hey, that's great news. Maybe there's a difference between 2017 and 2016 trucks. Either way, should save you a bit of cash. Remember to follow the break in procedure, it'll significantly impact the longevity of your new gears. I know it's a bit of a PITA, but makes a difference in how they break in. Remember to also not tow for more than 15 miles at a time after you get to 500 miles as well, for at least the first 45 miles or so. Give them a chance to cool in between runs, then you should be good to go. Enjoy the new found power and torque, you'll kick yourself for waiting this long to upgrade!
 

·
Registered
Joined
·
1,940 Posts
I have an '18 3500 SRW with Aisin. currently running 285/75-18s (35's). I want to regear with 4.10s. Will this be too low of a gear with 35s and the Aisin? I think next tire will be a 37" though
thanks
 

·
Registered
Joined
·
30 Posts
Discussion Starter #25
Thanks again, Speciulboy. I plan on driving empty for 3 weeks before making our next trip.
I know going to 3.73's won't make much difference, except in one area. When towing our fiver, 150 - 200 rpm higher will allow me to cruise more often in 6th on the interstate here in the Rockies. Big difference in MPG.
 

·
Registered
Joined
·
3 Posts
I been using Motive gears in several of my towing trucks and been having good results. Used Yukon gears several times and I do not like them as they made are in China and do not hold up. Motive made in Italy and have a much better forging and heat treating that hold up like the old Richmond gears did years ago.
 

·
Registered
Joined
·
1,940 Posts
4.10 is more than enough for 33’s 35’s and 37’s

I have a SRW and swapped to 4.10’s. I had 37’s but have since dropped to 33’s. Zero regrets. Transmissions love high rpm no matter if it’s Alison, RFE, or Aisin.
are there any tuning differences for the different gear ratios in trucks that have the Aisin?
For example, does a truck with 3.42 have a different tune compared to truck that came with 4.10s?
thanks
 

·
Registered
Joined
·
57 Posts
The shop where I had mine regeared said that he recommended AAM gears over the Yukon because the AAM gears would run quieter in the trucks. I did 4.10's and I run about 1800rpm's at 70 empty with a 68RFE. Truck runs strong now and trans doesn't hunt gears or struggle in the hills while towing.
 

·
Registered
Joined
·
30 Posts
Discussion Starter #33
We’ve made two trips pulling our 5th wheel, first 500 miles, second 1100 miles. So far, I’m very satisfied with the gear swap.
I’m seeing improved towing, which you would expect, but also slightly better MPG, (>0.5 increase), the latter probably a result of holding higher gears longer when climbing.
As far as the country of origin for the Yukons. My rear set was made in America, front set in China.
 

·
Registered
Joined
·
30 Posts
Discussion Starter #34
My installer said he didn’t recommend AAM, so who knows?
Couldn’t find any Richmond for my application.
Most Yukon gears are made in Chicago by US Gear.
 

·
Registered
Joined
·
9 Posts
I am gearing down my '17 from the 3.42's to 3.73's to better tow our fiver. The tech I spoke with who does a lot of swaps for Jeeps recommended Richmond's over OEM parts.
Any input either way or a different maker would be appreciated.
Thanks
I swapped mine from 3.42 to 3.73 a few months ago, 18 2500 2WD.
Used the OEM gearset p/n 68237849AB, don't know the p/n for the front.

Reason I did it is so I could tow our 5th wheel trailer in 6th gear @60-65 mph without lugging the engine on those long flat stretches of hwy.
I'm a retired heavy duty line mechanic from the 70's and swapped the gears myself.

Also, don't forget to re-configure the BCM to reflect the gear ratio change.
A gear ratio change does not affect speedometer, but it does affect torque management in the PCM. Easy to do using AlfaOBD.
There is a discussion about this on the turbodieslregister
 
21 - 36 of 36 Posts
Top