Suggested Rear Ratio?

Coach-man wrote:
One question not asked, what size tires are you getting? Regardless if you are towing anything the 20" tires would be too much with the 3.42 axle. At some point it would be nice to shift into 6th? Consider the 3.73 rear axle, unless your 5th wheel is really heavy. Good luck on your new purchase!

There's only a .2" increase in dia from 18 to 20" tires.
Firestone TransForce 20" are 33.4 and 18" are 33.2. Wouldn't make any difference. The 20" are 285/60 and the 18" are 275/70.

Read the tow specs for the truck, the rear end gear ratio is part of the configuration of the truck you need to tow the trailer you have identified. Forget the personal opinions and go with the facts.

One question not asked, what size tires are you getting? Regardless if you are towing anything the 20" tires would be too much with the 3.42 axle. At some point it would be nice to shift into 6th? Consider the 3.73 rear axle, unless your 5th wheel is really heavy. Good luck on your new purchase!

Congra'ts on the new Cougar 327 RES. We are currently out on our maiden trip with our 327. Not to debate gas vs. diesel we opted for a
Ford F250 Super Duty, 6.2L, 4.3 ratio, 6 speed, 8ft box.
Up until now all is great, should be in the Blue Mountain region later today.
Enjoy your new combo.
GPG

jus2shy wrote:
Looks like there was some ambiguity in regards to the rear gear. For RAM trucks in 2014, if you purchase a diesel in any SRW configuration (2500, 3500, single cab, crew cab), you only get the 3.42 rear end.

Now if you purchase a dually, then the flood gates open and you can pick 3.42, 3.73 or 4.10.

And if you are interested in the Aisin transmission, it is available only on the 3500's but for both SRW and DRW.

Personally, I own the 68RFE version of the SRW 3500. I figured that I don't own an RV yet and when I do finally get one, it will be hauled around only a few times a year. So no need to get something that in my eyes is overkill for my situation (and almost 3k more). I had to have my vehicle flashed twice before the shifting program was made right, but since getting its latest flash it's been shifting crisply and seems to be in the right gear at the right time for the most part. Seems like this was an issue with many 2013's. Many of the forums note that the 2014's seem to have the right programming right out of the gate for the 68RFE.

Thought I had said almost all that in earlier post. I've got the Aisin tranny and in almost 17,000 miles in almost 14 months, I've had zero issues with this truck, only updated software with radio/NAV (8.4an). The 68RFE is MORE than capable...I got the Aisin because I was curious as to what, in my opinion, was the tranny that Ram was trying to compete with GM's Allison...I've had 4 D/A combo's and they were awesome, won't say anything bad about them, but this Aisin will hold it's own with them.

As also stated, if you're not going to tow REALLY heavy, ie, 18,000# and upward...the 68RFE is MORE than enough tranny and you save about 3 grand.

I would stash away $1000.00 for new gears and then drive the rig and feel it out over a few trips with it. If your happy with it, no worries. If you want to change the gears, money is already available.
My 2011 Ram 2500 4x4 Mega Cab Hemi came with 3.73 in it. Ran great with my 11000# 5th. Put 33" tires on the truck and felt a huge difference pulling the trailer. Changed the 3.73 gears to 4.56 and its pulling better than it did stock.

DelCamper wrote:
I'm in the process of buying a 2013 Keystone Cougar 327 RES 5th wheel with a max weight of 12,000 lbs and a pin weight just shy of 1600. We're looking at a tow vehicle now and it looks like a 2014 Dodge Ram 2x4 quad Cab Diesel fits the bill.

My question is would the 3.43 read be ok or is the 3.73 or 4.11 necessary? Would the vehicle drive train break or wear out sooner with the lower 3.43 ratio?

Thanks....

"Would the vehicle drive train break or wear out sooner with the lower 3.43 ratio?"

Maybe you simply mis-stated that sentence.....:?

Of the three rear end ratios you stated - the 3.43 is the *highest* of the three. (4.11 is the lowest)

The 3.73 or 4.11 are *numerically* higher - but both are *lower* ratios than the 3.43.

The lower ratios will result in *higher* engine rpm.

There's no good answer to the "wear" question, a lot depends on your
driving style - and many other factors.


~

Looks like there was some ambiguity in regards to the rear gear. For RAM trucks in 2014, if you purchase a diesel in any SRW configuration (2500, 3500, single cab, crew cab), you only get the 3.42 rear end.

Now if you purchase a dually, then the flood gates open and you can pick 3.42, 3.73 or 4.10.

And if you are interested in the Aisin transmission, it is available only on the 3500's but for both SRW and DRW.

Personally, I own the 68RFE version of the SRW 3500. I figured that I don't own an RV yet and when I do finally get one, it will be hauled around only a few times a year. So no need to get something that in my eyes is overkill for my situation (and almost 3k more). I had to have my vehicle flashed twice before the shifting program was made right, but since getting its latest flash it's been shifting crisply and seems to be in the right gear at the right time for the most part. Seems like this was an issue with many 2013's. Many of the forums note that the 2014's seem to have the right programming right out of the gate for the 68RFE.

As mentioned, the 3.73 is overall a good rear end for your truck. That's what's in my 2500. The Aisin transmission is a heavier duty trans compared to the 68RFE. I haven't had a problem with my 68RFE, just changed the fluid at 50K.

DelCamper wrote:
I'm in the process of buying a 2013 Keystone Cougar 327 RES 5th wheel with a max weight of 12,000 lbs and a pin weight just shy of 1600. We're looking at a tow vehicle now and it looks like a 2014 Dodge Ram 2x4 quad Cab Diesel fits the bill.

My question is would the 3.43 read be ok or is the 3.73 or 4.11 necessary? Would the vehicle drive train break or wear out sooner with the lower 3.43 ratio?

Thanks....

Well I tow a 12,300# GVWR Keystone Copper Canyon 293 FWSLS, with an 01 about 270 HP and 540# ft. of torque with 3.55's. I don't have issues with hills can pull hills at speed.
I think you will do just fine.