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Towing Differences Between 3.73 Gears And 4.10


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i have a 2011 gmc 2500hd crew cab standard box with a 6.0 liter with 3.73 gears. i was flipping thru my owners manual the other night because i pull a toyhauler and a couple of different trailers, and just wanted to see the difference in towing specs for my truck. i was wondering why their was so much difference in a gcwr of 16000lbs with 3.73 gears and 20500lbs with 4.10 gears? i understand that 4.10 gears are a lower gear ratio and naturally should pull better, but wow 3500lbs is a lot of difference. especially when you look at the half tons with 3.42 gears and a 5.3 v8 have a gcwr of 15000lbs. i just makes me scratch my head. help please?

 

thanks!

 

Ransom

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I noticed the same thing too. I'm a little bit bummed that I settled for the 3.73 (no 4.10s on the lot), but at the same time I don't have my trailer yet, so I can plan accordingly.

 

To my knowlege, if you order a truck with 4.10s, all they do is add the 4.10, they don't add any additional cooling or breaks which could help with tow ratings. If the difference is ONLY the rear end, then the difference needs to be torque multiplication, and how GM does their tow ratings (I don't think they are on the SAE standard yet).

 

For example, if GM does a test up a mountain pass and the truck needs to haul X amount of weight across the pass at 90 degree ambeint and the criteria is that the truck must do this at a constant 60MPH and the tranny temp must be kept below 220 degrees F while going up the grade, then it is quite possible that with 3.73s you only get a 9600 tow rating while the 4.10s give you 12500 or whatever it was.

 

It's not just the rear gearing that matters, it's also the gearing of the 6-spd tranny and the torque curve of the engine. From the manual, it is obvious that the 4.10 gears are optimized for GM's towing test when combined with the engine torque curve and the 6-spd tranny. With 3.73s, the tranny might be in the wrong gear when on the test, causing the tranny to overheat and fail with a heavier load than 9600lbs.

 

 

Anyway, this is how I could see it happening. I'm not privy to GM's testing policies and I've searched numerous times to figure out how they come up with the numbers. If you read the future SAE standards for towing weights, you can easily see that it is extremely important for the tranny ratios, rear ratio, and engine torque curve to be matched for the SAE's hill climb test in order to achieve any respectable rating. If any of the three are out of whack, then you are going to get a penalty.

 

 

What stinks, is that if you ordered your truck, 4.10s were something like a $150 option at the time of installation.

 

Try adding them later to a 4WD truck. OUCH.

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Dropping from 3.73 to 4.10 will make a dramatic difference in engine RPM which moves the torque rating higher at the same highway speed. It will also increase wear & tear and fuel increase over the life span of the vehicle if you do a lot of non-towing driving.

 

As you obviously well know, be careful with tow ratings. They have no real value unless you are towing a load with the driver, no passengers and no cargo. What you need you look at is the GCWR (which you did). this will tell you the total load that the vehicle is rated to tow at (NEW).

 

What weight are you talking about towing? How much cargo and how many passengers (weights)?

 

If you are really maxing out the trucks ratings with the 3.73s, 4.10s may not be your best option (depending on how much you use the truck for non-towing). If you use the truck mostly for towing, you want a 20-25% margin. A 1-ton may be a better solution.

i have a 2011 gmc 2500hd crew cab standard box with a 6.0 liter with 3.73 gears. i was flipping thru my owners manual the other night because i pull a toyhauler and a couple of different trailers, and just wanted to see the difference in towing specs for my truck. i was wondering why their was so much difference in a gcwr of 16000lbs with 3.73 gears and 20500lbs with 4.10 gears? i understand that 4.10 gears are a lower gear ratio and naturally should pull better, but wow 3500lbs is a lot of difference. especially when you look at the half tons with 3.42 gears and a 5.3 v8 have a gcwr of 15000lbs. i just makes me scratch my head. help please?

 

thanks!

 

Ransom

Edited by wavery
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most of the time i will be driving this truck to haul the family. i have a toyhauler that i will pull 6 to 8 times a year, maybe more. but short trips. i weighed my toyhauler the other night fully loaded. fully loaded it tips the scales at 9300lbs. my gcwr of truck and trailer was 16350. (owners manual has 16000 gcwr) with my family in my truck its going to be grossing over 17000lbs. most of the time i pull the toyhauler close to home and not nearly as full. but i'd like to take a family vacation out to colorado and i don't want to damage something because i was overloaded, which really bums me when i see guys pulling stuff with half tons that need to be pulled with a 3/4 ton. and as far as tongue weight goes, the truck isn't even squatting that much, especially with the weight distribution hitch i have.

i know elevation really affects vehicle performance. but around missouri this thing fully loaded pulls really well. just concerned about the once a year mountain trip. 4.10 gears probably wouldn't be the solution for me either, cause the gas mileage will be far worse. my last 03 2500hd had 4.10 gears and it got horrible fuel mileage...which isn't why i bought the truck, but would like to have a little balance.....so here's my question, if i'm 1000lbs over weight pulling in the mountains will that be a problem? my truck is licensed with 18000 plates, which i know doesn't matter either, but i will be legal in the eyes of the law.

we live on a farm and haul loads of cattle, be it short distances and not nearly as a high elevation with no problem. i've pulled loads with my old truck where i was grossing over 22000 lbs. again i was pulling 30 miles to the stockyards to sell cattle. what it boils down to, is that i don't want to scorch my tranny pulling to big a load in the mtns. i figure when they test these trucks they would surely have to allow for slight overloading...wouldn't they? any more advice would be nice.

 

thanks!

:)

 

Dropping from 3.73 to 4.10 will make a dramatic difference in engine RPM which moves the torque rating higher at the same highway speed. It will also increase wear & tear and fuel increase over the life span of the vehicle if you do a lot of non-towing driving.

 

As you obviously well know, be careful with tow ratings. They have no real value unless you are towing a load with the driver, no passengers and no cargo. What you need you look at is the GCWR (which you did). this will tell you the total load that the vehicle is rated to tow at (NEW).

 

What weight are you talking about towing? How much cargo and how many passengers (weights)?

 

If you are really maxing out the trucks ratings with the 3.73s, 4.10s may not be your best option (depending on how much you use the truck for non-towing). If you use the truck mostly for towing, you want a 20-25% margin. A 1-ton may be a better solution.

i have a 2011 gmc 2500hd crew cab standard box with a 6.0 liter with 3.73 gears. i was flipping thru my owners manual the other night because i pull a toyhauler and a couple of different trailers, and just wanted to see the difference in towing specs for my truck. i was wondering why their was so much difference in a gcwr of 16000lbs with 3.73 gears and 20500lbs with 4.10 gears? i understand that 4.10 gears are a lower gear ratio and naturally should pull better, but wow 3500lbs is a lot of difference. especially when you look at the half tons with 3.42 gears and a 5.3 v8 have a gcwr of 15000lbs. i just makes me scratch my head. help please?

 

thanks!

 

Ransom

 

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First off...... One needs to understand that towing is about 30% about pulling ability and 70% about stopping ability.

 

In other-words, just because a vehicle can pull something to the top of a mountain really isn't a big deal. If the vehicle burns up on the way up, all of the pain is on that owner. What is a bigger deal is making it back down off of that mountain because if the vehicle fails to stop the load, the owner is not only going to feel a LOT of pain but others could be injured or killed at the same time.

 

Manufacturers are pretty accurate about vehicles maximum capacity ratings. They operate in a very competitive market and if one manufacturer can boast a higher rating than another (considering legal and warranty ramifications) they will. IMHO, it would be a very big mistake to over estimate the ratings of any one vehicle. Burning up a transmission is the least of your concerns...... killing someone is a far greater concern.

 

On flat lands, you may be just fine slightly over-loaded. In the mountains of Colorado, I would want AT LEAST a 20% buffer on my weight ratings (25% would be better).......... again JMHO.........

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so 20% below the gcwr or max trailer weight? at 20% off gcwr i'd be 12800lbs gcrwr for mtn towing? my max trailer weight i believe is 9400lbs which 20% would be 1880lbs, which the gcwr would be 14120lbs. i have trailer brakes and would use the transmission gearing to slow the vehicle too, but i do see your point about stopping.

 

i towed a bumper hitch trailer that loaded weighed about 5000lbs. i went over one mountain pass at 65 mph, no problem i would have been over 11000lbs gcwr with all our gear, luggage and passengers. i noticed gearing was more important than anything. with the manual mode i just left it in 3rd or 4th ant it pulled great. but that bumper hitch trailer isn't going to catch near the wind my toyhauler will either.

 

 

First off...... One needs to understand that towing is about 30% about pulling ability and 70% about stopping ability.

 

In other-words, just because a vehicle can pull something to the top of a mountain really isn't a big deal. If the vehicle burns up on the way up, all of the pain is on that owner. What is a bigger deal is making it back down off of that mountain because if the vehicle fails to stop the load, the owner is not only going to feel a LOT of pain but others could be injured or killed at the same time.

 

Manufacturers are pretty accurate about vehicles maximum capacity ratings. They operate in a very competitive market and if one manufacturer can boast a higher rating than another (considering legal and warranty ramifications) they will. IMHO, it would be a very big mistake to over estimate the ratings of any one vehicle. Burning up a transmission is the least of your concerns...... killing someone is a far greater concern.

 

On flat lands, you may be just fine slightly over-loaded. In the mountains of Colorado, I would want AT LEAST a 20% buffer on my weight ratings (25% would be better).......... again JMHO.........

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This is a pretty good site. Plug your #s in here and see how you do.

http://changingears.com/rv-sec-calc-trailer-weight-tt.shtml

 

They also recommend a safety margin of 20% (that would be 20% of your GCWR). Trailer brakes are taken into consideration in these calculations.

 

It should also be kept in mind that electric trailer brakes are not as reliable as your vehicle brakes. They should be tested regularly and at the 1st sign of ANY issues, one should pull off the road and check out the issue. A good understanding of electric brakes is essential with a load that large IMHO.

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Dropping from 3.73 to 4.10 will make a dramatic difference in engine RPM which moves the torque rating higher at the same highway speed. It will also increase wear & tear and fuel increase over the life span of the vehicle if you do a lot of non-towing driving.

 

Dramatic? 3.73->4.10 is 10%. 2200rpm vs. 2000rpm dramatic? I think not.

 

As you obviously well know, be careful with tow ratings. They have no real value unless you are towing a load with the driver, no passengers and no cargo. What you need you look at is the GCWR (which you did). this will tell you the total load that the vehicle is rated to tow at (NEW).

 

I agree.

 

I'm not sure why GM rates the two so differently. It seems the 3.73 is underrated and 4.10 is appropriate.

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i'm the same way. i don't understand how their can be so much difference between 3.73 to 4.10. i'd like to know how many people buy these trucks thinking they'll tow far more than they recommend?

 

Dropping from 3.73 to 4.10 will make a dramatic difference in engine RPM which moves the torque rating higher at the same highway speed. It will also increase wear & tear and fuel increase over the life span of the vehicle if you do a lot of non-towing driving.

 

Dramatic? 3.73->4.10 is 10%. 2200rpm vs. 2000rpm dramatic? I think not.

 

As you obviously well know, be careful with tow ratings. They have no real value unless you are towing a load with the driver, no passengers and no cargo. What you need you look at is the GCWR (which you did). this will tell you the total load that the vehicle is rated to tow at (NEW).

 

I agree.

 

I'm not sure why GM rates the two so differently. It seems the 3.73 is underrated and 4.10 is appropriate.

 

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I noticed the same thing too. I'm a little bit bummed that I settled for the 3.73 (no 4.10s on the lot), but at the same time I don't have my trailer yet, so I can plan accordingly.

 

To my knowlege, if you order a truck with 4.10s, all they do is add the 4.10, they don't add any additional cooling or breaks which could help with tow ratings. If the difference is ONLY the rear end, then the difference needs to be torque multiplication, and how GM does their tow ratings (I don't think they are on the SAE standard yet).

 

For example, if GM does a test up a mountain pass and the truck needs to haul X amount of weight across the pass at 90 degree ambeint and the criteria is that the truck must do this at a constant 60MPH and the tranny temp must be kept below 220 degrees F while going up the grade, then it is quite possible that with 3.73s you only get a 9600 tow rating while the 4.10s give you 12500 or whatever it was.

 

It's not just the rear gearing that matters, it's also the gearing of the 6-spd tranny and the torque curve of the engine. From the manual, it is obvious that the 4.10 gears are optimized for GM's towing test when combined with the engine torque curve and the 6-spd tranny. With 3.73s, the tranny might be in the wrong gear when on the test, causing the tranny to overheat and fail with a heavier load than 9600lbs.

 

 

Anyway, this is how I could see it happening. I'm not privy to GM's testing policies and I've searched numerous times to figure out how they come up with the numbers. If you read the future SAE standards for towing weights, you can easily see that it is extremely important for the tranny ratios, rear ratio, and engine torque curve to be matched for the SAE's hill climb test in order to achieve any respectable rating. If any of the three are out of whack, then you are going to get a penalty.

 

 

What stinks, is that if you ordered your truck, 4.10s were something like a $150 option at the time of installation.

 

Try adding them later to a 4WD truck. OUCH.

 

wavery,

 

i got to looking in my owners manual. even if i would have bought a 1ton pickup with 3.73 gears my gcwr would be the same. the max trailer weight is actually better on my 2500hd @ 9400lbs than a 3500hd dual wheel @ 9200lbs. maybe i should have bought a truck with 4.10 gears or ponyed up the extra 7 or 8 grand for a diesel. i see a 1 ton having no advantage outside of payload capacity. i guess i should have studied the numbers better, or have bought a smaller trailer. ho much did you say it was to add 4.10 gears?

 

thanks!

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I think that a lot of people buy tow vehicles that are under-rated for what they are towing.

 

Most people look at the tow rating of the vehicle and the dry weight of their tow (out of ignorance). This is a disaster waiting to happen because they don't consider the true weight that they will be towing..... For instance, my trailer has a dry weight of 2865#........ true scale weight 3980# (fully loaded). The Trailer manufacturer advertises that this trailer can be towed with a small, V6 SUV. They actually have a picture of a Rav4 towing the thing. To me, that is down right criminal. My Silverado 1500 V8 is pretty well maxed out. How is a small SUV going to "Safely" tow this thing over hills with a family and load of cargo for a camp-out?

 

When the true scale weight of the tow exceeds the weight of the tow vehicle everything changes. One must be very cautious in maintaining equipment and change their driving habits.

 

I think that the problem is mainly the trailer manufacturers, not the truck manufacturers. I am truly surprised that someone hasn't sued the pants off of TrailManor and/or other "Light weight" trailer manufacturers for over-stating what vehicles can safely tow their products. I think that the truck manufacturers are pretty honest about their rated capacities.

 

EDIT........ That's a shocker that the 1-ton has the same tow rating. Maybe that's why we see stuff like this once in awhile:

 

Thanksgiving07017.jpg

 

Ring & Pinion change is ~$800. If you do it, be sure to get it done at a dealer and be sure that the tech knows how to set-up the gears. If it is set-up wrong, you can destroy the new ring & pinion on your 1st tow. I'd rather have GM backing up the job than an independent. YA!!!!!! it will cost you more but at least you can pull into any Chevy dealership and get the warranty honored.

Edited by wavery
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I think that a lot of people buy tow vehicles that are under-rated for what they are towing.

 

Most people look at the tow rating of the vehicle and the dry weight of their tow (out of ignorance). This is a disaster waiting to happen because they don't consider the true weight that they will be towing..... For instance, my trailer has a dry weight of 2865#........ true scale weight 3980# (fully loaded). The Trailer manufacturer advertises that this trailer can be towed with a small, V6 SUV. They actually have a picture of a Rav4 towing the thing. To me, that is down right criminal. My Silverado 1500 V8 is pretty well maxed out. How is a small SUV going to "Safely" tow this thing over hills with a family and load of cargo for a camp-out?

 

When the true scale weight of the tow exceeds the weight of the tow vehicle everything changes. One must be very cautious in maintaining equipment and change their driving habits.

 

I think that the problem is mainly the trailer manufacturers, not the truck manufacturers. I am truly surprised that someone hasn't sued the pants off of TrailManor and/or other "Light weight" trailer manufacturers for over-stating what vehicles can safely tow their products. I think that the truck manufacturers are pretty honest about their rated capacities.

 

EDIT........ That's a shocker that the 1-ton has the same tow rating. Maybe that's why we see stuff like this once in awhile:

 

Thanksgiving07017.jpg

 

Ring & Pinion change is ~$800. If you do it, be sure to get it done at a dealer and be sure that the tech knows how to set-up the gears. If it is set-up wrong, you can destroy the new ring & pinion on your 1st tow. I'd rather have GM backing up the job than an independent. YA!!!!!! it will cost you more but at least you can pull into any Chevy dealership and get the warranty honored.

 

 

i've seen several trailers that say half ton towable, and i don't understand how the trailer manufacturers can do it. that exactly why i bought the truck i bought. i just figured it would be enough to pull it. since i'd looked at a few smalled trailers that claimed half ton towable. i think i'm going to hold off doing any big trips that will require towing in the mountains until i decide to upgrade the gearing. i'm going to check with my dealer to see what they'll charge me to do it. my toyhauler weighs 7000 dry. but with my polaris ranger, and a small atv with other gear needed for camping it hits more like 9300. the trailer is rated for 10400, but i doubt i'll ever get that much in it. we do have a trip down to arkansas in sept to ride atv's in the ozark national forest. hwy 7 from harrison AR thru jasper will be a good test, but nothing like driving over monarch or loveland pass. i love my truck so far, i still don't regret not buying a diesel.

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The trailer manufacturers can do that because they sell the trailer at or near dry weight. If the customer decides to add accessories, cargo etc......... the customer assumes all liability from that point on.

 

In a way, the vehicle manufacturers do a similar thing with the "Tow rating" of the vehicle. Most vehicles are rated for towing with no passengers and zero cargo. The difference is, the vehicle manufacturers usually make the statement something like, "Any passenger and/or cargo weight must be subtracted from the tow rating" and the Owner's Manual will go on to make it even more clear.

 

The NTSB has passed new guidelines for tow ratings for auto manufacturers. I hope that they do something to make trailer manufacturers be more honest in their advertising.

 

BTW........ I highly recommend that you take your fully loaded trailer to a CAT scale and get it weighed. You may be in for a shock...... I know that I was...... I figured that my trailer would weigh 3500# TOPS!!!! (there's just my wife and I). When they handed me the slip that said 3980, I had them weigh it again.

Edited by wavery
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The trailer manufacturers can do that because they sell the trailer at or near dry weight. If the customer decides to add accessories, cargo etc......... the customer assumes all liability from that point on.

 

In a way, the vehicle manufacturers do a similar thing with the "Tow rating" of the vehicle. Most vehicles are rated for towing with no passengers and zero cargo. The difference is, the vehicle manufacturers usually make the statement something like, "Any passenger and/or cargo weight must be subtracted from the tow rating" and the Owner's Manual will go on to make it even more clear.

 

The NTSB has passed new guidelines for tow ratings for auto manufacturers. I hope that they do something to make trailer manufacturers be more honest in their advertising.

 

BTW........ I highly recommend that you take your fully loaded trailer to a CAT scale and get it weighed. You may be in for a shock...... I know that I was...... I figured that my trailer would weigh 3500# TOPS!!!! (there's just my wife and I). When they handed me the slip that said 3980, I had them weigh it again.

 

i know a farmer that has a set of scales that are certified by the state of mo dept of ag. i've weighed everything and it wasn't that far off for what i thought it would be.

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The trailer manufacturers can do that because they sell the trailer at or near dry weight. If the customer decides to add accessories, cargo etc......... the customer assumes all liability from that point on.

 

In a way, the vehicle manufacturers do a similar thing with the "Tow rating" of the vehicle. Most vehicles are rated for towing with no passengers and zero cargo. The difference is, the vehicle manufacturers usually make the statement something like, "Any passenger and/or cargo weight must be subtracted from the tow rating" and the Owner's Manual will go on to make it even more clear.

 

The NTSB has passed new guidelines for tow ratings for auto manufacturers. I hope that they do something to make trailer manufacturers be more honest in their advertising.

 

BTW........ I highly recommend that you take your fully loaded trailer to a CAT scale and get it weighed. You may be in for a shock...... I know that I was...... I figured that my trailer would weigh 3500# TOPS!!!! (there's just my wife and I). When they handed me the slip that said 3980, I had them weigh it again.

 

i know a farmer that has a set of scales that are certified by the state of mo dept of ag. i've weighed everything and it wasn't that far off for what i thought it would be.

 

 

 

a duramax diesel will out-pull and out-last any 6.0 truck,while getting better fuel milage and less up keep,

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