newbie and confused

[rubsal70]

Merry Christmas,
I am new to this forum and looking to Buy a TT and I have done some research. I have a Chevy Silverado 1500 4.8 with 3.23. Max trailer weight is 4700 and gcwr is 10000. Well if I change my gears to 3.73 that would raise my Max trailer weight 6700 and 12000 gcwr. Well that's my truck.

The TT that I am looking at is a jayco Jay swift 264bh. The yellow stickers on the TT range from 4500-4600lbs. My question is, is this safe? With the gear change or not? Please advice
Thanks in advance

[gmw_photos]

wmoses wrote:

gmw photos wrote:
Wayne,
Share it with the rest of us ? Maybe we can all learn from someone who has actual experience in changing out the rear gears, etc.

thanks.

This thread may shed some light. 🙂

Hi Wayne,
Yes, I remember that thread, and followed it at the time. That's a good one with some things for the OP to read through.
So bottom line is, it sounds like you are pretty happy with your set up ?
With the six speed auto ( I am assuming the OP's truck is a six speed ) I would think that for normal highway use between lets say 40 to 65 mph, a guy should have almost all driving conditions covered with third through fifth ? Yes, I could see steep pulls in the mountains in second if he has a trailer that is 5000 to 5500 pounds. My experience has been that in the overall miles of a trip, there are relatively few miles driven that are that steep though.

[wmoses]

gmw photos wrote:
Wayne,
Share it with the rest of us ? Maybe we can all learn from someone who has actual experience in changing out the rear gears, etc.

thanks.

This thread may shed some light. 🙂

[gmw_photos]

wmoses wrote:
OP - PM me if you have any specific questions. I have actual experience in this issue. So much material in this thread I am not surprised if you are even more confused than when you drafted your original post. 😉

Wayne,
Share it with the rest of us ? Maybe we can all learn from someone who has actual experience in changing out the rear gears, etc.

thanks.

[wmoses]

OP - PM me if you have any specific questions. I have actual experience in this issue. So much material in this thread I am not surprised if you are even more confused than when you drafted your original post. 😉

[gmw_photos]

rubsal70 wrote:
@miltvill really 6-7mpg??? I usually get 14-17 without towing. That seems awfully low.
@handye9 well when we go out tent camping or to the coast and rent a home for vacations. We usually don't buy anything until after we have settled in. We take clothes, fishing rods, empty coolers, (tents, sleeping bags, camping stuff when camping), empty buckets and that is it. When we plan on going with our TT we will try to limit also like when we go any other times. I won't need to add water cause they have it at the sites and also dump stations are at sites. I will take the payload seriously though and probably go to a weight station.
@larry and gmw photo how much of a difference would I see in my mpg if I go to a 3.73 or 4.10
You guys are right I will not be towing everyday. I will do towing maybe about once a month at the most and summer twice a month but that is it.
Thanks for all the help I appreciate and I am learning a lot.

Regarding gas mileage, it's probably fair to say that it's typical to see the gas powered tow vehicles use "almost" double to double the fuel compared to non towing.
Example in my case, pulling this Funfinder with the Nissan Frontier ( 4.0L V6 gas, six speed manual ) I get between 17 and 23 mpg non towing, and between 9 and 14 towing. The overall average for a long trip with the trailer is always right around 12.3 to 12.5.

Here's a another real world example for you to chew on: we also have a one ton dually ( Ford powerstroke diesel ) with 4.10 gears. It gets 9 to 11 mpg all the time....does not matter if it's empty or pulling the 35', 13,000 pound horse trailer, or the 14,000 equipment trailer loaded with hay.
You will need to simply accept that towing and good gas mileage just do not go together.

As for the difference in fuel mileage if you were to switch from a 3.23 to a 4.10, I am going to make "guess" here ( and I stress this is just a guess ) that your towing mileage is probably going to be about the same with either gear. Your non towing mileage is probably going to be from one to three less with the 4.10. Probably about one to two mpg worse in city use, and two to three worse on highway cruising empty. Those are my guesses.

[rubsal70]

@miltvill really 6-7mpg??? I usually get 14-17 without towing. That seems awfully low.
@handye9 well when we go out tent camping or to the coast and rent a home for vacations. We usually don't buy anything until after we have settled in. We take clothes, fishing rods, empty coolers, (tents, sleeping bags, camping stuff when camping), empty buckets and that is it. When we plan on going with our TT we will try to limit also like when we go any other times. I won't need to add water cause they have it at the sites and also dump stations are at sites. I will take the payload seriously though and probably go to a weight station.
@larry and gmw photo how much of a difference would I see in my mpg if I go to a 3.73 or 4.10
You guys are right I will not be towing everyday. I will do towing maybe about once a month at the most and summer twice a month but that is it.
Thanks for all the help I appreciate and I am learning a lot.

[JJBIRISH]

chart and formulas

tire size and gear calculators

[gmw_photos]

LarryJM wrote:

gmw photos wrote:

As for changing the ring and pinion in the trucks rear end, you do understand that an easier way to get the engine to rev higher, is to simply use a lower gear in the transmission ? The whole object of the game in going to a lower gear ratio in the final is to get the engine to rev higher up into it's powerband. Which is exactly what you do when you leave the trans, let's say in third, rather than in fourth. If I were in your shoes, I would choose and buy the trailer, and try towing with it before going to the expense of changing the final gears.

While that is true at cruising speed there is the acceleration factor and such things as torque multiplication where a higher rear end gear will help a lot in getting all that weight up to speed. A higher rear end gear will give you more "power" where the rubber meets the road as you accelerate up to your final cruising speed.

Like some others have posted personally if you are going to change the rear gears from your current 3.23 I would seriously consider skipping the 3.73 and go straight to the 4.10 if the costs are close to the same. Except for some the the newest diesels and some of the more modern trannys with 6 speeds, etc. the typical "TOWING" rear ends are in the 3.73 to 4.30 range.

Larry

Larry,
What you say is true. And if we want to get technical about it, to take it a little further, going to a lower ratio rear end also helps reduce the strain on the transmission, since "more" of the torque multiplication is taking place at the ring and pinion. In theory anyway, with a lower rear gear he could see cooler trans temps.
This is likely part of the reason Toyota has chosen 4.30 gears in the late Tundras. It makes life easier on the trans. Late GM trucks though have gone the other way, with higher rear gears, and choose to get the torque multiplication in the trans.
Having said all that, my point in suggesting to the OP he try it out first with the stock gears is because changing rear gears is fairly expensive, and depending on the trailer he chooses and what his towing expectations are, he may be satisfied with what he has. One needs to consider too what percentage of their annual driving with this vehicle is towing vs simple everyday use. For occasional weekend use, and a couple week vacation once a year as a tow vehicle, it may make more sense to just leave the rear end gears alone, and deal with somewhat slower acceleration while towing.
Going from his existing gear to a 4.10 or so is going effect his gas mileage some in daily non towing use as well.

Another thing for him to consider would be when it's time to replace tires on the truck, going to a tire with a slightly smaller rolling diameter has the same effect as lowering the gear ratio.

While I won't go so far to say these small block chevy V-8's are gutless, I will admit, both this engine and 5.3 like to rev. True small block design there, they are tuned so that you have to rev them. Do it.....won't hurt a thing, except maybe gas mileage.

I agree with Larry also that the change from 3.23 to 3.73 is not much of a change, so if going to the trouble to change them, I too would go to 4.10 or even 4.30. OP, there are charts and graphs online that will allow you to see what change of rpm you would see by changing the gearing. You might want to do a little homework on it.

ps. where is the hone-o-drive when we need it ? 🙂

[LarryJM]

gmw photos wrote:

As for changing the ring and pinion in the trucks rear end, you do understand that an easier way to get the engine to rev higher, is to simply use a lower gear in the transmission ? The whole object of the game in going to a lower gear ratio in the final is to get the engine to rev higher up into it's powerband. Which is exactly what you do when you leave the trans, let's say in third, rather than in fourth. If I were in your shoes, I would choose and buy the trailer, and try towing with it before going to the expense of changing the final gears.

While that is true at cruising speed there is the acceleration factor and such things as torque multiplication where a higher rear end gear will help a lot in getting all that weight up to speed. A higher rear end gear will give you more "power" where the rubber meets the road as you accelerate up to your final cruising speed.

Like some others have posted personally if you are going to change the rear gears from your current 3.23 I would seriously consider skipping the 3.73 and go straight to the 4.10 if the costs are close to the same. Except for some the the newest diesels and some of the more modern trannys with 6 speeds, etc. the typical "TOWING" rear ends are in the 3.73 to 4.30 range.

Larry

[handye9]

rubsal70 wrote:

jerem0621 wrote:

rubsal70 wrote:
Guys Merry Christmas again. Thank you all for the info that y'all have given me. As of right now it looks like I'll be changing to 3.73 gears. I also will be adding a transmission cooler to it. What else would I need. The way we camp with the family is we just take clothes, cooler and some gear. It never totals 500 lbs of cargo. Besides the cooler what else do y'all recommend. My truck is not a 4x4 so only rear axle change would be needed. I do plan on getting a WD with sway control and obviously brake control for the trailer. Do I need to upgrade brakes to my truck also? I appreciate the info. I'm a little confused but to me it makes sense that changing gears will add max tow as per manual and like others have confirmed. To the person who posted the video to me and like someone said it doesn't look stressed. Any one else have any more advice please let me know. I will try to make a decision in the next week or two
Thanks

Here is a thought... Instead of 3.73 why not go to a 4.10 now. The cost is the same and you should not notice much difference between the two in daily driving. However, towing will be much nicer with the 4.10.

Thanks

Well my truck's manual has two options under the same engine. My current 3.23 and the 3.73 gears. I thought I was only able to do 3.73. If I do 4.10 what is my max tow? Also with the 3.23 the gcwr was 10000. With the 3.73 it has 12000 gcwr. What would it be for 4.10?

The gear changes may increase the weight rating of what you might put behind the truck, but, they will not increase the trucks GVWR or it's payload (weight you put on the truck). Those are the first places you will go over weight. A bigger number in tow capacity, may lead you to think you can tow a heavier trailer, but, that heavier trailer will also come with more tongue weight.

You stated earlier, your payload was 1650 lbs. If that is advertised payload, it may not be your actual payload. The truck may have arrived at the dealership, with 1650 payload, but, anything added by the dealer or the customer, such as bed liner, bed mat, floor mats, hitch, bed cover, bed cap, etc, will reduced the payload pound for pound. Add a 200 lb bed cap, and, 1650 payload becomes 1450. You mentioned adding a tranny cooler, even that will reduced your payload by however much it weighs.

To find your actual payload available, weigh the truck with full fuel and driver. Subtract that weight from GVWR as printed on your door post. You might find your available payload is more like 13 - 1500 lbs. That is what you have to work with for passengers, cargo (in the truck), WD hitch (about 100 lbs), and trailer tongue weight. Doesn't matter what you do with the rear end gears.

Some numbers to think about:

If you start out with 1400 lbs payload and:
subtract 100 lbs WD hitch
subtract 400 - 500 lbs for passengers
subtract 200 - 300 lbs for cargo in the truck
You only have payload available for 500 lbs tongue weight.
Plug in your own numbers to see where you're at.

Average camping load (groceries, water, camp chairs, dishes, and bedding) is 11 - 1200 lbs, 10 - 15% of this will be on the tongue

Average tongue weight is 12% of gross trailer weight.
6000 lb (loaded for camping) trailer = about 720 lbs tongue weight
7000 lb (loaded for camping) trailer = about 840 lbs tongue weight

Water weighs a little under 8 lbs per gallon. Thirtyfive gallons in your holding tank is close to 280 lbs, just in your fresh tank.

Grey water and sewage weighs more per gallon than fresh water.

Advertised trailer weights are from empty trailer leaving the factory.
The selling dealer adds propane, battery, and some options. When the trailer leaves dealer lot, tongue weight is normally 100 - 150 lbs higher than advertised.

Trailer sales people will tell you "No problem pulling a trailer that has unloaded weight with in your tow capacity". Except for delivery guys, taking it from factory to dealer, NOBODY TOWS EMPTY.

[miltvill]

When I purchased my present TT my TV was the same truck you have only a 1999 with less horse power and tow package. My TT weighs about 5000 pounds. My TV did ok. I towed in third gear with the tow/haul mode on. But my towing is Florida towing with small hills and mostly flat roads. I did have to use 2nd in some heavy head winds. I never towed above 63 mph. The truck is the same truck as the 5.3L version. Expect 6 to 7 mpg towing. Make sure you put LT tires on your TV. My TV was also 2wh drive. The 3.73 rear will help a lot.

[rubsal70]

It's a 2010 hitch receiver? It is 600 and1000 with WD.

[Ron_Gratz]

rubsal70 wrote:
---I have a Chevy Silverado 1500 4.8 with 3.23. Max trailer weight is 4700 and gcwr is 10000.---

What year is your Silverado?

What are the tongue weight ratings on the receiver?

Ron

[rubsal70]

I do understand. I just didn't want to seat at max tow so by changing gears I would increase my max tow.

[gmw_photos]

rubsal70 wrote:

gmw photos wrote:

rubsal70 wrote:
Guys Merry Christmas again. Thank you all for the info that y'all have given me. As of right now it looks like I'll be changing to 3.73 gears. I also will be adding a transmission cooler to it. What else would I need. The way we camp with the family is we just take clothes, cooler and some gear. It never totals 500 lbs of cargo. Besides the cooler what else do y'all recommend. My truck is not a 4x4 so only rear axle change would be needed. I do plan on getting a WD with sway control and obviously brake control for the trailer. Do I need to upgrade brakes to my truck also? I appreciate the info. I'm a little confused but to me it makes sense that changing gears will add max tow as per manual and like others have confirmed. To the person who posted the video to me and like someone said it doesn't look stressed. Any one else have any more advice please let me know. I will try to make a decision in the next week or two
Thanks

My opinion is that the brakes that GM fit to your truck is certainly fine for what you are going to do. Lets face it.....it's a truck, so it was made for carrying and towing more of a load than a car.
Lots of choices in WD hitches, and several also in brake controllers. I chose a BlueOx swaypro, and a prodigy P2 brake controller, but there are certainly others out there that would, I'm sure, work just as well. Hopefully others will chime in with their experiences of their chosen gear.

Well my truck is coming on needing new brakes so maybe someone can chime in. How do trailer brakes work?

Trailer brakes are typically drum brakes, that are electrically actuated. When the trailer is plugged into the tow vehicle, there is electric power available to them. The brake controller that will install in the truck, sends varying amounts of power to the trailer brakes based on how hard you are braking. The brake controller is adjustable, and when you do your initial setup, you will go thru a procedure that fine tunes the controller to the trailer. Once properly set up, the traile and truck braking systems work well together for safe efficient stopping.

As for changing the ring and pinion in the trucks rear end, you do understand that an easier way to get the engine to rev higher, is to simply use a lower gear in the transmission ? The whole object of the game in going to a lower gear ratio in the final is to get the engine to rev higher up into it's powerband. Which is exactly what you do when you leave the trans, let's say in third, rather than in fourth. If I were in your shoes, I would choose and buy the trailer, and try towing with it before going to the expense of changing the final gears.