2015 3500 ram

[jhenderson]

You don't tell us where you're from or where you intend to go. Mountains? Are you going to use it every day or solely for towing? It all makes a difference. I pull a 9 ton GN on secondary roads and plow snow. I wish I could have gotten the 4:10 rear. It depends on the mission.

 

[cerberusiam]

My question is, which rear end gear ratio would be best for pulling?

The 4.10's hands down. Upsize the tires a bit and you will get back some of the economy. The weight you are towing doesn't warrant a dually but it gives future options.

My dealer kept telling me the Aisin is an 8-speed. Of course I never corrected him. :-laf

Technically, dealer is correct. All triple planetary 2 clutch packs per are 8 speed capable. However, functional gearing is another story.

 

[TCDiesel]

Look at the speeds 75MPH SD/ND, MT/UT/WY 80MPH Speed is up just about all of N/A, I pulled My 4 Place snowmobile trailer Across those States during winter Months, The last trip I was 80-85MPH form West Yellowstone I90/94 I said to Myself the tires will need replacing for Next Season.... Nope I had to Stop in Dickinson ND to replace all 4. That being said I enjoy driving that speed across those states with 10-12MPG, If I had 4:10/3:73 DRW maybe 70 would NET 8-10MPG Hmmm 75MPH Maybe 6-8MPG.....I will never go back to DRW until I start pulling 30K LBS across country, I do pull 22-30K LBS during the construction season Here with No problems. SRW-3:42. DRW at one time were necessary to carry additional LBS (back in 70-80s) ,With tire technology today they are only necessary in extreme GVW. Yes I have Txi-axle trailers, Tandems, Drive-ons, Flats, Dumps I've pull them all. Yes I have a weekend warrior Trailer also.

Don't be in fear of SRW and 3:42 ,Just make sure its a 3500 SRW with Aisin.

 

[Cummins12V98]

"Don't be in fear of SRW and 3:42 ,Just make sure its a 3500 SRW with Aisin"

I would completely agree especially on the upper weight limits of the SRW trucks. Same for a Dually towing up to 27K or so combined.

 

[NIsaacs]

You don't tell us where you're from or where you intend to go. Mountains? Are you going to use it every day or solely for towing? It all makes a difference. I pull a 9 ton GN on secondary roads and plow snow. I wish I could have gotten the 4:10 rear. It depends on the mission.

I agree. I assume you are talking all three are duallys. If high speed is important, loaded or empty, get the 3.73, if maximum towing at slower speeds is important, get the 4.10. Leave the 3.42 for the SRW trucks or the 6spd manual dually. The 3.42 is fine (SRW) for those trucks because that is all that is available, kinda like the Model T back in the day. You could get any color as long as it was black. If the 3.73 were the only gear available in the SRW it would make one fine tow hauler, especially if a little bigger tire is needed/wanted. A bigger tire on a 3.42 is not a good idea.

Nick

 

[dfb]

I agree. I assume you are talking all three are duallys. If high speed is important, loaded or empty, get the 3.73, if maximum towing at slower speeds is important, get the 4.10. Leave the 3.42 for the SRW trucks or the 6spd manual dually. The 3.42 is fine (SRW) for those trucks because that is all that is available, kinda like the Model T back in the day. You could get any color as long as it was black. If the 3.73 were the only gear available in the SRW it would make one fine tow hauler, especially if a little bigger tire is needed/wanted. A bigger tire on a 3.42 is not a good idea.

Nick

Can always swap gears....

 

[BILLUA]

3.73 hands down with the AISIN. Locking out 6th because you have 3.42's means you bought the wrong truck

 

[SnoKing]

3.73 hands down with the AISIN. Locking out 6th because you have 3.42's means you bought the wrong truck

Not for those that tow only a 1/4 - 1/3 of the time!!!!! If would be a mistake with an old 4 speed auto, however with 6 gears, the motor does not lug out between gears. As long as it can get the load moving and shift up through the gears without lugging then the gears are not to tall.

spend most of the day at 80 MPH in each truck and then decide which gear ratio is best.

SNOKING

 

[NIsaacs]

spend most of the day at 80 MPH in each truck and then decide which gear ratio is best.

SNOKING

Per my gear calculator: 3.42 at 80 is 1755 rpm running 33" tires. The 3.73 at 80 is 1914 rpm.

Nick

 

[AH64ID]

Aside from the very high GCW'S IMHO the biggest factor in 3.42 vs 4.10's is the speed at which you operate while towing. The faster you tow the lower the need for 4.10's, but if you spend all summer in the winding mountains at low speeds the lower gear choices make a huge differenc even at lower GCW'S

A SRW truck with the OEM 18's would only be at 2156 at 80 with 4.10's. Nothing wrong with that, IMHO. That's fewer rpms than I do st 80 now with 19.5's and 3.73's.

 

[SnoKing]

Had these gears for 14 years with 4.10's and 31.65" LT265/75R16's
47RE RATIOS
Gear: Ratio:
1 2.45 : 1 Speed at 1000 RPM's 9 MPH
2 1.45 : 1
3 1.00 : 1 Speed at 2000 RPM's 46 MPH
4 0.69 : 1 RPM's at 80 MPH 2400
R 2.21 : 1

Had these gears for 7 months with 3.42's and 33.19" LT275/70R18's
AISIN AS69RC RATIOS With 3.42's
Gear: Ratio:
1 3.75 : 1 Speed at 1000 RPM's 8 MPH
2 2.00 : 1
3 1.34 : 1
4 1.00 : 1 Speed at 2000 RPM's 58 MPH
5 0.77 : 1 Speed at 2000 RPM's 75 MPH
6 0.63 : 1 RPM's at 80 MPH 1750
R 3.54 : 1

(just for comparison at the same 2000 RPM's 4th gear with 3.73's would be 53 MPH in forth and to low, and 5th gear with 3.73's would be 69 MPH and to high)

AISIN AS69RC RATIOS with 3.73's
Gear: Ratio:
1 3.75 : 1 Speed at 1000 RPM's 7 MPH
2 2.00 : 1
3 1.34 : 1
4 1.00 : 1 Speed at 2000 RPM's 53 MPH
5 0.77 : 1 Speed at 2000 RPM's 69 MPH
6 0.63 : 1 RPM's at 80 MPH 1900
R 3.54 : 1

AISIN AS69RC RATIOS (with 4.10's)
Gear: Ratio:
1 3.75 : 1 Speed at 1000 RPM's 6 MPH
2 2.00 : 1
3 1.34 : 1
4 1.00 : 1 Speed at 2000 RPM's 48 MPH
5 0.77 : 1 Speed at 2000 RPM's 63 MPH
6 0.63 : 1 RPM's at 80 MPH 2100
R 3.54 : 1



One whole gear more before you get to 1 to 1 ratio. And one more overdrive ratio. Even with 3.42's the Aisin has a better launch ratio than 4.10's and the 47/48RE.

Now for hill climbing on mountain passes look at 3rd in the 47RE and 4th in the Aisin. I always said the 47RE and 4.10's was gear bound, because when I had to come out of overdrive on mountain passes I was forced to slow down to much because of gears and high RPM's. The 3.42 and Aisin have solved that issue in spades.

3.73's would make 4th a little low for hill and 5th would be a little to tall. Now for the 4.10 gears, hill climbing on mountain passes would be in an OD ratio in 5th and not in a 1.1 drive ratio with lighter loads similar to what one would be towing with a SRW and with heavy loads you would be in 4th turning lots of RPMs or slowing down.

I think RAM got is right for SRW trucks, if one opts for the Aisin transmission.

Did I say I love my Aisin and 3.42's for a SRW truck.

Snoking

 

[NIsaacs]

You are giving me a head ache, with a 150 rpm difference between the 2 gears none of that means squat....

Nick

 

[SnoKing]

Doesn't mean squat to you, however to RAM and many owners it does. I am sure that RAM tested it with the other two ratios and decided they were not necessary. They run out of rear tire capacity way before they run out of gearing with the 3.42's.

SNOKING

 

[NIsaacs]

Ram is not perfect, remember the console latch?

Nick

 

[SnoKing]

Ram is not perfect, remember the console latch?

Nick

SO your 2001 has 3.55's, with did you not get the 4.10's?

SNOKING

 

[NIsaacs]

I don't like 4.10's with one overdrive, It was used also.

If Ram made all the rear axle choices on the SRW as the dually, there is nothing wrong with dropping the GVW/GCW on the high gears, make the percentage the same.

Nick

 

[SnoKing]

I don't like 4.10's with one overdrive, It was used also.

If Ram made all the rear axle choices on the SRW as the dually, there is nothing wrong with dropping the GVW/GCW on the high gears, make the percentage the same.

Nick

Yep, I can do that now by pushing in the TOW HAUL button, everything goes down a gear, and the truck running around bobtail sounds busier! SNOKING

 

[Cummins12V98]

" A bigger tire on a 3.42 is not a good idea." Completely agree!!!

If you want to drive fast 3.42's are the way to go.

 

[SnoKing]

" A bigger tire on a 3.42 is not a good idea." Completely agree!!!

If you want to drive fast 3.42's are the way to go.

View attachment 95429

How many RPM's to make the 4.10's go that fast? SNOKING

 

[AH64ID]

How many RPM's to make the 4.10's go that fast? SNOKING

Approx 2878 to go 103.