Should You Re-Gear Your Diesel for 37s?

I'm Andrew and I'm setting out to make better videos for diesel enthusiasts follow along as I review products do how to's and share my personal trucks here on just Diesel's today we are going to tackle one of the most disputed topics in diesel trucks for some reason rege earring with 37 s or just any larger tire has become like the hot topic I see it on Instagram I see it on Facebook I see on YouTube everywhere that he will post trucks with you know largely the stock tires someone is there commenting did you rig ear that truck you have to rig your that truck you're gonna ruin that truck if you don't read gear so today we are going to settle this debate once and for all and if you were on the fence about doing 37 s or whether or not you should review this video will answer that question once and for all now before we get any further in this video let's talk about why you would want to run 37 s so one they look cool right they fit proportionally with the best size of these big trucks they look awesome but too the big reason to run 37 tires is one you get improved rollover so the larger the diameter of the tire is the easier it rolls over obstacles like rocks or holes or anything like that so you get a smoother ride you're actually more capable and then too the only way to get an axle of a vehicle farther away from the ground is with increased tire size so you can lift the truck to the moon but if you're trying to get the axles farther away from the ground for better ground clearance especially in a solid axle vehicle the only way to do that is with larger sized tires now I'm going to run you guys through some of my personal experiences but before I want to do that I want to actually take you guys through the hard numbers so online there's these great things called gearing calculators you can use those to determine where your factory starting ratio is and what your new ratio is going to be with the larger tires so I will link that in description below I will link that in the comments you can go and check this out for yourself but basically we're gonna do is input your factory tire size your factory gear ratio and then your new tire size what this calculator is gonna spit out at the end is your final gear ratio your final drive ratio after the new tires so this is actually really helpful information so that you can actually get a concrete number on what your gear ratio is starting and ending it you can then use that information to figure out where you need to go now a lot of these gearing calculators will also spit out a number that says the ratio you need to be at to go back to your factory ratio with the larger size tire and that's a key number because I always see people online saying you need this really ratio or you need that gear ratio and there is no youni this or that it all depends on the math so if you want to figure out exactly what gear ríos do you need to get back to your factory gear ratio even though you're running 37 s these calculators are going to give you a definite real answer on that now let's look at my truck as an example I have a 2006 Ram 2500 now that truck is a 5.9 liter Cummins diesel with the 48-hour read transmission that truck comes with a 373 factory gear ratio and originally came with 265 7017 tires now I'd put on a 37 12 and a half 20 that puts my final gear ratio to 3.19 with the new tires in order to get back to the factory ratio I would need to add 437 gears now that's not a very common size so I'd be choosing between 410 and 456 now I've had friends with this exact truck put 456 gears on take them off to go back to 373 or 410 so here's why I'm gonna explain you may not actually want to recur your truck it all depends on how you're using it for my personal example I chose to not Rieger my truck I stuck with the factory 373 gears and here's why I have a 48 re transmission that is a 4-speed automatic transmission I found that on the factory size tire anything over 70 miles an hour I was over 2,000 rpm over 2,000 rpm is actually getting out of the efficiency and kind of powerband of the most torque you're gonna get out of these engines so I actually found that my truck was one more efficient and to more pleasant to drive with the thirty-seventh line because lower the RPM now when I'm cruising at 70 with 37 s I'm running right around like 1800 rpm to 1600 somewhere in there and it's a lot more pleasant of an experience at 80 I'll get up to 2,000 rpm so it actually puts my truck in a more efficient range in the power band when I'm cruising on the highway and I actually find that I really like it now I also toe with my truck I pull a dump trailer all ho dolt whole you know trucks and cars and stuff like that it's usually stuffed below ten thousand pounds so in my personal situation I have no downside when I'm towing I don't have really higher EG tees i'm not lugging the truck is not hunting for years everything performs as it should yes the rpms are a little bit lower than they would be if I was on the factory tire size but this is a diesel they really they don't care if you put a little bit of extra load on them basically with the 37 s it would be like I was towing a 13,000 pound trailer instead of a you know ten thousand pound trailer the truck doesn't really care it's it's made to do that it's made to haul it's made to have a load on it and it performs just fine with really no ill effect now sometimes I'll be climbing up a hill and the truck will kind of hang on to forth for a little bit too long so I'll just drop it in tow haul mode they'll go into third of the lockup and I'm doing just fine so for my personal case I really have no need to be here now I'm sure you've all heard someone online tell you that you have to recur you have to this you have to do that don't listen to everyone online do what you think works best for your truck if you go on this online gearing calculator and you see at the ratio it spits out really isn't that far off from what your at run 37 see how your truck drives I guarantee you you probably won't want to rehear most of these trucks that I see most of my friends on 37 s are not reviewed their trucks drive just fine everything performs as it should you can reach overdrive everything works great and actually like their trucks better because they operate a little bit lower in the RPM band now I'm not saying that's the absolute way to go if you feel strongly about rehearing by all means go ahead and rehear I'm not gonna tell you what's wrong you are reducing the mechanical load on your truck you are absolutely putting it back to where it was designed to be from the factory I'm just saying that on a diesel truck you can actually get away without redoing because these trucks are designed to tow they are designed to haul and they are designed to have a little bit of increased load on the engine now if we're talking about like it's a coma right it's a small v6 yeah you're gonna want to read gear because doing a 30-7 alone just the added rotational mass of that tire it's gonna put a lot of strain on the v6 but in a big diesel it has 600 with thousand foot-pounds of torque they really don't care they're doing just fine with 37 so I just wanted to walk you guys through that I want to give you my personal example show you guys an online gearing calculator and show you guys how to get a concrete number of what your new root gear ratio is what ratio you need to actually get back to factory so I give you guys all the information to make the decision on your own I can't tell you if you should regear your truck that's ultimately the decision up to you but I can tell you that you probably should drive it on thirty-sevens see how it feels and probably nine times out of ten I see people not Riku unless you're towing huge trailers regularly your hotshot guy something like that which you probably shouldn't even be on 37 s anyway that's probably when you're gonna want to read here but for most of these guys that are running empty trucks especially the guys that are using them for like over landing camping and things like that there's really not a huge reason to keep regear I'm very happy on my factory 373 gears but 37 s and I have no intention of changing that so hopefully that helps you guys make decision for your own that was my personal decision you can say I'm wrong but my truck and I'm very happy with it so yeah let me know what you guys think comment below if you plan on rehearing if you have Riegert if you haven't let's let P the discussion going I'd love to hear from you guys and see how you feel about rehearing on these diesel trucks so thank you guys so much hopefully that helps hopefully that helps shed a little bit of light in the subject and maybe it'll end some arguments maybe it'll start somewhere so thank you guys if you enjoyed this video please comment below subscribe and I will see you guys on the next one

Channel: Just Diesels

Views: 22,808

Rating: 4.9477434 out of 5

Keywords: cummins, powerstroke, diesel, dodge ram, ram, dodge, carli suspension, carli, lift, lifted, lifted truck, 5.9 cummins, Ram, Dodge, Ford, 7.3 powerstroke, f-25-, f-350, 2500, 3500, trucks, lifted trucks, diesel trucks, diesel truck, re-gear, regear, re-gearing, regearing, tires, 37s, 35s, 38s, 40s, 3rd gen, 4th gen

Id: V0dmkpNy11Q

Length: 8min 20sec (500 seconds)

Published: Wed Jun 10 2020