Would 35" Tires on the stock 3.55 Gears be a good combination? Should I change up to 4.10 or maybe 4.56? I might also get 37" tires later, would the same gears apply? Thanks!


Would 325/60R20 Tires (Nitto Terra Grapplers) Fit ok on the stock 20x9 Rims? Thanks!

 

I know you didn't mention towing, but you should get a lot out of this:

https://dodgeforum.com/forum/3rd-gen...nsmission.html

 

I have 315/75r17, so basically 35's. I also have 3.55 gears and have no issues. This last weekend I towed my trailer, loaded about 7500lbs with no issues. You could set the cruise and let it do it's thing. You could tell it was back there, but no issues. I could see some 3.92's or higher doing a better job, but these did perfectly fine. Would I pay to switch them? No. If I was ordering another truck, would it have 3.92's yes.

Just for reference, pulling 7500+, up a 9 percent grade, my wife was behind me in her 2008 Caravan. She had the pedal to the floor and I pulled away. Granted, she has the small engine in it, but I think it is worthy of merrit.


Going to 37's, I think could warrant a gear change.

 

3.55's with 35's - 65mph on the speedo = 70mph actual. The change is pretty small around 10%. I run about 1900 RPM's if I put it into 5th (so it won't use MDS). If I stick at 62~65 on the speedo and baby it, it will stay in MDS and drop to 1600RPM's... but I don't get any better mileage... so I stick with v-8 mode.

Gears and a locker would be nice... it's funny in 4th Gen everyone loves the 3.92's and limited slip, check out the 3rd Gen section and they aren't fans. Probably within the next year or so I'll go to an Auburn with 4.10's, but I'm not in a hurry.

 

I've run 3.55s with 35" tires and didn't have any probs but if money is no issue and you tow a heavy load regularly I'd do a gear swap (especially if you plan on towing with 37" tires) and save some long term damage to the tranny. I'm happy with my current 3.55s and 33s so no gear swap in my future.

 

Hey all thanks for your help! It has helped a lot, I dont really tow regularly so changing gears isnt on my priority list I guess but something I'll do in the future when I change to 37's

 

35s with 3:55 gears SUCK!! I had it for a week and while my 4:56 gears and rear locker were on order. I guess they would be good if you drive like an old grandma

 

First person I hear saying that ^^

 

well if you dont want different opinions dont ask the question.

if you dont mind not having any take off speed what so ever they might be good for you or if you drive only on the highway they might also be good for you, but if you plan on going mudding or city driving alot i def. wouldnt recomend it

 

Here's some raw data.

Your effective gear ratio after installing 35" tires will be 3.22.

At 65 MPH with that set up here are the RPM numbers.

3rd = 2216
4th = 1662
5th = 1463

My experience with 3.55 gears and 31" tires on my '09 hemi tells me that your truck will be downshifting to 3rd quite often with any grade change (such as an overpass).

For comparison, here are the numbers for 3.55 effective ratio at 65MPH

3rd = 2447
4th = 1835
5th = 1615