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Old 01-22-2023, 09:34 AM   #1
MISailor
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Axle Ratios - Supply Chain Issues

Hi, All.

I'm thinking about replacing my TV and am running into supply chain issues that make an "exact" replacement of my TV essentially impossible. My current TV is a 2013 Chevy Silverado 1500 Crew Cab equipped with the 5.3L V8 and the trailer package witch adds the 3.42 rear axle, external oil cooler, etc. This has been a very capable set up for my 2013 Bullet Premier 19FBPR.

Supply issues at GM make finding a new 1500 with the 3.42 axle essentially impossible (even the 5.3L engine is somewhat rare), and I have not gotten a good answer yet regarding when one will be able to order a vehicle equipped with a 3.42 axle. Check the Chevy inventory nationwide and you'll find a ton of trucks with the 2.7L engine and 3.23 axle. I think I'd be disappointed with one of those. I'm not in a huge hurry so I can wait, and I'm thinking that is the best thing to do but would like someone to validate (or challenge) my thinking on the best axle ratio for my situation.

The 3.23 axle is readily available and would be fine 90+ percent of the time since we do not tow a lot. Regardless, I'm thinking that we should equip the TV for the (minority) time that we do tow, rather than the majority of the time when we don't. The trade off for a more capable TV is accepting lower fuel economy the rest of the time and I can accept that. The 3.73 ratio seems like overkill for our trailer based on good experience with the 3.42, especially considering that I think it would require accepting the 6.2L gas or 3.0L diesel.

The main question is...is the 3.23 axle a non-starter for my situation?

FWIW, I have some financial incentive to stay with GM, so I have not looked into other brands.
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Old 01-22-2023, 09:37 AM   #2
jasin1
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does it have the 10 speed transmission? i believe they are rethinking axle ratios because of lower first gear
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Old 01-22-2023, 10:14 AM   #3
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Originally Posted by jasin1 View Post
does it have the 10 speed transmission? i believe they are rethinking axle ratios because of lower first gear
That's a good question that adds additional factors to the equation. The 5.3L engine would come with a 10-speed transmission. My current truck just has a 6-speed, FWIW.
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Old 01-22-2023, 10:58 AM   #4
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I would opt for the 3.73 long before I'd go for a 3.23 to tow. The 3.23 is for going to the grocery store and not for towing...it wants light loads and gives decent gas mileage. A 3.73 is not the best for towing or going to the store but a good all around compromise. Your 3.42 axle is OK for your trailer since it's not real big. The 3.23 would be a big letdown in every dept. IMO. If you can get the 3.73 I'd go for that without a 2nd thought. My last several trucks have been 3.55, 3.92, 3.73 and 4.10. To tell the truth there isn't enough difference in gas mileage between them to worry about. However, there is a big difference in how they handle a load.

On those new transmissions IIRC they don't really throw in really low "granny" gears but more fill in the gaps left in a 6 speed transmission. That really helps when you have a load behind you. Most trucks with a decent axle ratio and adequate engine can take off pretty good....you just hate it when it hits that next "hole" - speaking to gas engines.
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Old 01-22-2023, 01:29 PM   #5
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In the interest of fuel mileage, many manufacturers are going with lower gear ratios combined with more transmission gears. The 2013 5.3L makes 315 HP and 335 lb-ft of torque and has cylinder cutout (active fuel management) and probably flex fuel capable (E85). My Tahoe Z71 had the same setup but with 3.55 axles, but I never towed with it. I don’t think GM is offering any of those fuel saving features now, so lower axle ratios may be related.

My last truck was an F150 with the 3.5L Ecoboost V6 which made 365 HP and 420 lb-ft of torque and had 3.31 axles. I averaged 9 mpg towing and 17-18mpg around town. It was a towing beast with the HP and torque negating the low axle ratio.

Before you decide to wait too long, remember that GM is already phasing out their gas and diesel powered vehicles to be 100% zero emissions in the next 10-12 years. Many people are so brand loyal that they often don’t consider other manufacturers that may offer a product better suited to their needs/wants. I have owned Ram, Chevy, GMC and Ford. The brand depended on who offered close to what I needed at the time. I liked/disliked certain aspects of each, including a couple of things with my current truck I am not a fan of, but it does what I want/need now and what I want/need it to do for the future.
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Old 01-22-2023, 02:01 PM   #6
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Quote:
Originally Posted by NH_Bulldog View Post
Before you decide to wait too long, remember that GM is already phasing out their gas and diesel powered vehicles to be 100% zero emissions in the next 10-12 years.
GM gas engines are not going anywhere anytime soon.

https://jalopnik.com/gm-is-investing...nes-1850013640

It will be much longer than 10-12 years, since they just announced a huge investment in the next gen V8 development.
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Old 01-22-2023, 02:35 PM   #7
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It was a bit tongue in cheek. Personally, I take all of it with a grain of salt; GM themselves say they will be 100% zero emission no later than 2035. California set a 2035 zero emission date followed by Massachusetts and Washington state. Is it realistic? Probably/hopefully not, as evidenced by their words seemingly being the opposite of their actions.
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Old 01-24-2023, 04:09 PM   #8
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My opinion is that with the 6, 8. and 10 speed transmissions that are the norm now, axle ratio just isn't as critical as it was back when all we had were 3 or 4 gears to choose from. And seeing what ratios are available now (really what ratios are NOT available) I believe the engineers are in agreement.

My old 97 F-350 dually with the 7.3 had 4:10 gears. And needed them! I had around 500 or so foot/lbs of torque (chipped) and it did an amazing job pulling what ever I asked it too.

Or at least it seemed amazing. Right up until I got my current F-350! The difference is like night and day. With twice the torque and horsepower of the old engines and more gears, these newer trucks move the loads effortlessly. At least this is true here in the diesel camp.

As a matter of fact, the truck I make a living with (2021 Pete) w/Cummins X15 of the 500 hp variety with 1650 ft/lbs of torque, has 2:85 axles with a 12 speed auto shift transmission. This rig is rated at 80,000 lbs and we've had over 82K on it a couple of times. And depending on the load, we get anywhere from 7 to 10+ mpg. Our empty weight is around 38K lbs for tractor and trailer.

I know it's kinda apples and oranges comparing this to the one tons and lesser trucks that we use to tow our RV's but these newer transmissions have changed the game for sure. I'm sure the higher ratios in our pickup trucks are a result of the transmission options and I'm also convinced that the reason you can't get that 3:73 or 4:10 gearing is to preserve the manufacturers CAFE numbers.


https://www.nhtsa.gov/laws-regulatio...e-fuel-economy
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Old 01-29-2023, 08:46 AM   #9
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Rear ratio

NOT DEBATING MAKES, MODELS, just sharing my experience. We had purchased a new 2014 5th wheel 10,800lbs dry and wanted to match a TV. Cost/ benefit did not warrant a diesel nor did we want a dually. After much research we changed brand, factory ordered: 3/4 ton,6.2 ltr, 4:30 ratio,6 speed. ALSO chose options that would meet our towing needs: 8ft box, tow package, snow plow package to beef up suspention and alternators, 4x4 with elock, electric mirrors, rear window ect. Surprising, reasonable gas mileage for this brut. We have towed all over Eastern Seaboard, Kentucky, Carolina mountains ect. All good.. best of all in 2014 we only paid $46k Cnd.
Works for us
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Old 01-29-2023, 10:01 AM   #10
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Appreciate the Comments - Test Drove 2 Engines

Thanks for the comments, all. You offer wisdom and worthy considerations.

We test drove two F-150s this week. The first had the 3.5L Ecoboost 6 cyl and I did not like it at all. It may have more max power and torque than the other Ford engines, but I found the delayed call for power when pushing the peddle down very uncomfortable. It did not feel like this engine would deliver on rare occasions where immediate acceleration was urgently needed. The second F-150 was equipped with the 5.0L V8, and although it has a bit less max power and torque than the 3.5L Ecoboost, I was MUCH more comfortable driving it because it responded immediately when I asked it for more power.

We hope to test drive a Ram this week, but barring any surprises by the Ram, I think we may be headed towards ordering a 2023 F-150 crew cab w/ the 5.0L V8 and the 3.55 rear end.
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Old 01-29-2023, 10:09 AM   #11
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The comments about the 3.23 ratio with the 10 speed tranny are, I think, valid.
GM chart says 5.3 with the 8 speed and 3.42 ratio has the same rating as the 10 speed with the 3.23.
I don't think GM in the 1500 offers anything but the 3.23 and 3.42 in gas trucks
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Old 01-29-2023, 11:16 AM   #12
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I have debated changing out my 3:70s for the 4:10. I really doubt my gas mileage would change much. As per my sig, 8.1 with Allison...
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Old 01-31-2023, 07:40 AM   #13
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My truck has a 6.4L engine, 6 speed trans and 4.10 gears. My other truck has a 5.7L, 5 speed and 4.56 gears. Not great mpg, but better than I ever expected compared to my past vehicles.
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