DODGE RAM FORUM banner

Towing with 3.21 gears

14K views 21 replies 12 participants last post by  snrusnak 
#1 ·
I have a 2010 1500 quad cab with the 5.7 2wd and I think 3.21 gears, not 100% sure about the gears as I bought the truck used. My understanding is that if I do have 3.21 I can only tow 6,750lbs and if thats the case can I just regear to 3.55 or a bigger ratio and that will allow me to tow more. I don't tow that often but when I do the numbers I pull according to the scales are going to be with in about 600lbs of that number, I haven't checked the numbers with my WD Hitch. Any info would be very helpful.
 
#3 ·
If you dont tow alot, and want to keep any kind of fuel mileage, 3.55s will do fine. They will up the tow capacity. To what, Im not 100% about.

If you were towing every day, or not concerned with mileage, 4.10s would be great.
 
#4 ·
If you are going to go to the expense and trouble of re-gearing, I would think you would be better served to skip the 3:55 and go to at least 3.92. As mentioned before consider 4:10 if towing often and heavy and/or not concerned with mpg loss. The 3:55 in most cases should do fine, but again may not be the best choice if going through the effort of swapping gears. Not sure on your year, but on my 2012 I have 3:55 and it is rated to tow up to 8400 lbs., if I had the 3:92 the rating jumps to 10,000.
 
#6 ·
I have 3:55 and tow a 6.500 lbs travel trailer about 6 - 8 times per year. For me it works fine, yes it does some gear hunting with that ratio, but I drop it in 4th in the tow haul mode and trans temp stays cool.

If you were towing more than that, then I agree with the others and skip the 3:55 and go 3:92 or 4:10. If your not, why waste the gas mileage, unless you are looking for a performance truck.

According to Dodge, http://www.dodge.com/bodybuilder/2011/docs/ram/rammlup1500.pdf you can tow 6,750lbs with 3:21, 8,750 lbs with 3:55 and 10,250 with 3:92. Get your dealer to check your VIN for your gear ratio.
 
#7 ·
Thanks Guys, in my Tundra it did not have a gear option, but I think it had 4.10 and pulled whatever I wanted it to. The Ram has options and the dealer is looking into this matter for me, I'm just nervous that there is more to do than a simple regear to truly increase "towing capacity" hopefully it will be a simple fix. I just don't want to tow and be nervous the whole time about if it will hold up or not. Also I crawled under my truck and noticed that the hitch is only the small bolt up bracket piece not the full frame to frame kind. The dealer said it is the factory installed hitch on all 1500 so it can handle the 10,000 towing capacity, but all I can find are the aftermarket ones that are rated for 6000 lbs trailer capacity. Does anybody know more about that, it too would be helpful.
 
#8 ·
I had the horrible 3.21's in my 09 2wd. 1st thing I did after buying it was off to the local 4x4 shop for a set of 3.92's. was like night and day difference. Also I got much better mileage. The truck it to heavy for the 3.21's. also forget 3.55's I have them in my 13 and I hate them. I though they would be better on gas. Nope and the truck feels so much slower it makes me miss my 09. Oh well live and learn. It's getting new gears soon as the lift and 35's go one.
 
#9 ·
Re gear

Just out of curiosity, how much are guys spending getting your trucks geared. I only ask because I'm being quoted 800$- 1450$ and I'm 2wd so it's only the rear axle. I know you get what you pay for but wow. I'm trying to get itemized quotes to see if some are rebuilding with new bearings and all or just replacing the ring and pinion. The trucks only got 22,000 miles so I don't think I would need a rebuild but I also know that sometimes you have to replace certain parts in order to get a quality product at the end. Also I'm in San Antonio Tx so if anybody know of a good shop to do the regear please let me know.
 
#10 ·
changing gears will defintiely effect towing capacity. Maybe not "officially", but it will make it easier to pull the weight. If you get stopped by a cop and are over your vehicles rating, I don't know that they will care that you changed gears.

I have 3.55 with a 4.7L and tow 4000ish lbs now and again and it's no sweat. I'd imagine a hemi with 3.55's would pull 6000 lb no sweat.

Honestly the weight isn't a big deal, it's the damn drag from the trailer that gets me.
 
#11 ·
Cost me $800 for the G2 3.92's with install and the rebuilt kit.
 
#12 ·
Well, it looks like I have 3.21 gears. I have been quoted 1,250 up to 1,500$ to regear to 3.92, seems rather steep to me. Which has got me thinking about just going to a junkyard and getting the VIN off of a truck and looking up which ratio it went with. If it has low enough mileage just service the rear end and swap them out. Do you guys think it would an ok route, the yard rear end is 185$. So I would be saving around 1,000$ or more.
 
#15 ·
I am currently trying to find a person that ordered 3.55 gears but received 3.21 gears (effectively reducing your towing capacity by around 2,000 pounds) that lives in Missouri. I need someone willing to be a class representative in a class-action lawsuit to get this matter resolved. I have this problem with my truck, but obviously cannot be the attorney that files the lawsuit AND the class representative. Send me a private message with your phone number if you meet the criteria and are willing to answer interrogatories and do a deposition on the matter. The class representative generally receives compensation greater than the rest of the claimants for their time and energy spent in serving.
 
#17 ·
most likely 3.55 maybe 3.92. Rare choice is 3.21.

Your build sheet will tell you. It has nothing to do with sport model, just depends what they ordered. 3.55 is standard. Only the RT has "special" gearing, which is 4.10.
 
#18 ·
I have the 3.92's and once I increased the tire size, I wish I could have inexpensively changed my gear ratio front and rear to the neighborhood of 4.56. I tow about 30% of the time. Stock tire size and 3.92 is the minimum ratio I feel for any truck of this class/weight if you tow. I do not need to go down the highway at 1600 rpm. In fact I feel that too low of a ratio combined with this much weight actually hurts economy. Not fun to constantly hunt between 5th and 4th up average hills @ 65-70 mph.
 
#21 ·
rsg, 1600 rpm on the highway is surely in 6th gear. You should use tow/haul. You must not be using tow/haul if you're at 1600rpm anywhere around 65/70mph.
Always in tow-haul when towing. I was actually referencing (not very well) load-free driving. I have taller than stock tires so I know that accounts for a small bit of the RPM drop from stock. But even empty she hunts gears too easily at those speeds. Just lightly accellerate and the tranny downshifts as if I were climbing a hill. Higher numerically gears would help put her right about 1,9000-2,000 at those speeds, which would help a lot.
Stock tires, and 3.92's are probably perfect for how I use the wifes truck. But stock is not how we roll so we pay the price...ugh.
 
#20 ·
I don't tow nearly as much or as heavy as I used to so the new half ton was my choice. Mine does have the 3.92 ratio and I think it really helps the engine stay in MDS mode. Mine is 2wd but my cousin has a 10 sport 4x4(3.92) and my best friend has a 13 4x4(3.55). The 3.55 truck gets consistently worse fuel economy on the highway. I told my buddy to watch for his eco light and he commented that with the cruise set at highway speed it rarely comes on and usually only down hills. My truck and my cousins 10 ram cruise comfortable at 70-73 mph with the ECO light on all the time and MDS activated unless it is into a healthy head wind or going up a grade.

Ryan gets around 18 highway best with the 13 and Drew and I consistently see over 20 as long as it isn't windy. The 4x4 isn't really a factor as my 10 and Drew's 10 see very similar highway numbers.

Not to mention, the 13 with 3.55s is a pooch compared to the 3.92 trucks.

Towing these days usually consists of either my boat (about 3400 lbs with trailer and fuel) or my car (about 6000 lbs with trailer and car). The truck will motor right down the highway in overdrive lock up only downshifting for steeper than normal grades.

I think the 3.92 is the best all around choice for these trucks. With the advent of the variable valve timing moving more and more torque down low at cruise rpms we don't have to hunt around for gears as much as gassers of 10-12 years ago.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top