Calgary Jeep Association
4x4 Related Groups => Tech Talk => Topic started by: Tinkerer on April 18, 2010, 04:47:12 PM
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???
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The nice thing about the Rubi is that you've got 4.10 gears already, and the long wheelbase. That'll definitely help.
The downside is that you're running that 3.8, and through an auto transmission if I recall correctly. I'm hoping that you've got a tranny cooler fitted - otherwise you may run into issues if you're in BC.
In general, trailer brakes will simply make it safer to tow up to and including the rated towing capacity for the vehicle. Even with trailer brakes, your engine and transmission still need to do a lot of work. I think that the rated towing capacity for an Unlimited is 3500 pounds...I personally would not want to go beyond that unless I'd installed an upgraded transmission and a Hemi.
I haven't tried it, but I'd say that a JK with a full family on board and 3500 pounds of trailer would be a bit of a handful going across the continental divide.
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The easy answer is two-fold.
#1. Most pick-ups are actually larger and heavier than even an unlimited. You're looking at something the size of a Ford Ranger if you want something that's equivalent.
#2. Trucks are meant for moving dirt. Jeeps are meant for moving across dirt ;)
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The rated capacity assumes that you have properly working brakes on the trailer.
Brake controlers come in various styles and price ranges. The "True" progressive brake controlers either tap into your brake line or have a potentiometer attached to your brake pedal to measure how much braking you are doing. Both are tricky to install and expensive.
The regular electric ones work quite well. The basic Tekonsha Voyager sells for around $50-$80 if I remember right and will work for most people most of of the time and would be fine for what you are doing.
The Prodigy is a higher end unit and allows more fine tuning but is about twice the price. Goggle them both for the differences.
You should be able to buy a pigtail with the controller that will plug right into a connector under the dash. This will make the install plug and play. If you cann't get the pigtail with the controller then go get one from the dealer and mate it to the harness that came with the controller. DO NOT hack into the wiring under the dash to install it. The computers on new vehicles don't like that.
If you bought the vehicle new with a factory tow prep package you may have recieved the harness with the vehicle from the factory. My sister's '01 Dodge Ram 1500 came with one in the dash. Sat in there for ten years till she wanted to install a brake controller and needed it.
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all sorts of neat things affect the towing capacity. on trucks having 4wd or not is a big difference. as well the rear end gear ratio and which rear end it has. dodge dakotas with a 9.25 rear end have a higher capacity then the ones with the 8.25. pretty much think of the 3/4 ton and 1 ton trucks. the 1 ton trucks can carry and tow more because they use a bigger rear end with different ratio, different rear leaf packs as well. and then add the dual rear wheel set-ups. different engine cooling and transmission cooling. dont forget the rating on your hitch.
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I saw various threads that touched on towing capacities for the different model Jeeps, but was curious whether having proper electric trailer brakes was included in the rated towing capacity, or would effectively increase it.
I don't want to create a dangerous situation and/or get stopped in BC and have the holiday stopped cold due to exceeding ratings.
Thanks!
PS: We would be using Michie's 2008 Wrangler Rubicon Unlimited for towing, and likely would add an electric brake controller. (I have a basic one in the garage, but I'd love proportional braking... not sure how that would work or how expensive it would be.)
I am not sure of the weight of the trailer you are trying to tow, but I think you will have to regear. Even with 4.10's in the rubi, with the automatic it has to downshift at the slightest grade or headwind. I would like a trailer, and if I do get one I will put in the tranny cooler and regear the diffs.
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Thats not quite true but the theory is sound.
On the Dodge diesels a 4.10 axle ratio will give a higher rating than one with 3.73s. However the drivetrain, including the rear axles and brakes is exactly the same between a 2500 and a SRW 3500. The only difference between the two trucks is the rear leaf spring pack and the decal on the door. Add a set of airbags to a 2500 and you now have the same capacity as a SRW 3500.
There are also two different numbers to look at for towing capacity, this applies mainly to the heavy stuff, not so much SUVs.
GVWR-gross vehicle weight rating, how much the truck can carry. This is the max amount the truck can weigh with people/fuel, cargo in the box and hitch weight. Trailer weight does not come into play other than what the hitch weigh adds to the trucks weight. Subtract the vehicle's curb weight from the GVWR and this is roughly how much the truck can carry. This is where a DRW(dually) has the advantage as its dual rear wheels allows for a much higher weight carrying capacity.
GCWR- gross combined weight rating. This has to do with how heavy a trailer you can tow. A Dodge 3500,SRW or DRW have a GCWR of 23,000#, so the truck, all its gear, cargo, fuel,people and trailer together must weigh less than 23,000#. So take the weight of the truck, cargo in box, people,fuel etc, subtract that from the GCWR and that leaves how heavy of a trailer you can tow. Here's the interesting thing, because a DRW truck weighs more than a SRW truck the SRW has more left over for the trailer. Technically a SRW truck can haul a bigger trailer than a DRW. Same goes for 2wd/4wd, a 2wd regular cab truck will weigh less than a 4wd crew cab leaving more left over for the trailer.
Realistically though a trailer THAT heavy is going to require either a 5th wheel hitch or gooseneck hitch and will transfer so much hitch weight to the truck that you would exceed a SRW truck's GVWR or overload the rear axle rating meaning that a trailer that big/heavy would require a DRW to handle the hitch weight.
Here is an excellent site for figuring out the tow ratings on almost any 2002+ Dodge vehicle. Sorry no Jeeps in it.
http://www.dodge.com/towing/D/vehicle_to_weight.jsp
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Or you do this to avoid tripling....
(http://i166.photobucket.com/albums/u92/clayhardock/DSC_1131.jpg)
or this if you REALLY want to get crazy....
(http://i166.photobucket.com/albums/u92/clayhardock/ToyHauler%20Build/DSC_3614.jpg)
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Actually it is now legal to tow two trailers in bc...if your gross combined vehicle weight is over 11,000 kg.
I was hoping to get the chance sometime this summer.
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Hmm interesting, Are they asking for a special license for that? Do you have any links?
When you say must have a GCWR over 11,000kg does that mean you must be towing with a truck that is rated for 11,000kg GCWR or does it mean you must actually be driving a rig thats over 11,000kg GCWR?
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Thats kinda what I thought, 11,000kg is 24,000# and over the GCWR for any one ton truck that I know of. You would need to step upto a Ford 450 or Dodge 4500 which puts you into the commercial category.
I know there are car trailers that big for hauling race cars and such that have living quarters in them but I think they are forcing those guys to register as commercial.
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Yes I've heard stories about a guy that got nailed while hauling his daughter's horse to a horse jumping event. Pretty stupid if you ask me.
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Hmm interesting, Are they asking for a special license for that? Do you have any links?
When you say must have a GCWR over 11,000kg does that mean you must be towing with a truck that is rated for 11,000kg GCWR or does it mean you must actually be driving a rig thats over 11,000kg GCWR?
I believe the truck/trailer combination in total must be over 11,000 kg. I saw several road signs on my last trip out to the coast, last october. I seem to recall the signs stating it was a pilot project. It gave me a chuckle at the time since I was driving a 24,000 pound vehicle flat towing a 4000 pound jeep....I get some funny looks with my rig already, but I'm sure I'd get more with a trailer behind the jeep behind the motorhome...just the rv and the jeep are 60 feet long!
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how many vehicles do you own boone?
I know of at least 2 jeeps, likely another vehicle for the misses, and a motorhome now, plus some dirt bikes I think too.
steve
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I guess it depends how you count...but too many that's for sure. 2 jeeps that run, 2 jeeps that need to be combined to make one runner and one scrapper, 4 trailers, do trailers count? my work truck, rv, wife's car...
All of my vehicles combined are probably worth less than one nice new car though. my xj cost $100 and my rv was free!
no dirt bikes of my own, but my little guy has a 50cc.
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not bad, a free RV, what a good deal.
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I admit i did not read to detail all the above, but have the following input to share.
You can run up to 11,794k on a private plate/non commercial provided that you are a non for hire vehicle. Non for hire is hauling your own equipment (RV, Race car and trailer etc). a complete unit will in most cases be a single axle tractor with juice brakes and electric on triple axle trailer or a single axle tractor with air brake (require a 5Q license) and electric on trailer.
This is how the big RV unit run.
Most trailers are built to allow a maximum of 15% weight migration to hitch of vehicle towing.
Trailer brakes are a requirement over 3500lbs and also suggested by most manufactures for towing a trailer where the trailer and its combined payload are over 3500 lbs. So take your trailer and think of it as it must be capable of breaking its own load with no more than 15% of it being directly transfered to the pull vehicle. If it exceeds, by a bigger vehicle.
GVWR of a vehicle is 100% based on braking capacity and tire size and not gear ratio. The reason that most people associate it to gear ratio is that they will note that a spec of a vehicle changes when you compare tires size to gear ratio in brouchures. This is to maximize rpm range for pulling and fuel economy.
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GVWR stays the same with a gear ratio change but it does affect GCWR.
The Dodge 3500 is 21,000# with 3.73 gears and 23,000 with 4.10s.
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Correct me if I am wrong, but I believe there is a difference in regulations if you are "trippling" with 2 bumper pull trailers and one goose neck trailer and one bumper pull trailer. I can't remember why or where I was reading about it being legal to pull a gooseneck with a bumper pull trailer, but I am very sure there was a difference in what was legal and what was not.
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I admit i did not read to detail all the above, but have the following input to share.
You can run up to 11,794k on a private plate/non commercial provided that you are a non for hire vehicle. Non for hire is hauling your own equipment (RV, Race car and trailer etc). a complete unit will in most cases be a single axle tractor with juice brakes and electric on triple axle trailer or a single axle tractor with air brake (require a 5Q license) and electric on trailer.
This is how the big RV unit run.
Most trailers are built to allow a maximum of 15% weight migration to hitch of vehicle towing.
Trailer brakes are a requirement over 3500lbs and also suggested by most manufactures for towing a trailer where the trailer and its combined payload are over 3500 lbs. So take your trailer and think of it as it must be capable of breaking its own load with no more than 15% of it being directly transfered to the pull vehicle. If it exceeds, by a bigger vehicle.
GVWR of a vehicle is 100% based on braking capacity and tire size and not gear ratio. The reason that most people associate it to gear ratio is that they will note that a spec of a vehicle changes when you compare tires size to gear ratio in brouchures. This is to maximize rpm range for pulling and fuel economy.
hmm., I think I am over the figure you mentioned at 24,000lb for motorhome and 4000lb for "trailer" (jeep) yet I am on a regular plate and insurance...?
and yeah trailer brakes really help, I got this thing for flat towing my jeep which would be described best as a "freaky contraption" it's called the evenbrake and it's basically a box that sits on the driver's florr and contains a small air compressor, a air powered ram and some circuitry including a momentum sensor. Basically at a selectable rate of deceleration the air ram will shoot out with 75-100 lbs of force onto the brake pedal and slow the vehicle. the massive force is required since the system functions without vacum and therefore without power brakes so the brakes are in hard and weak. Let's just say you'd best be followin' the instructions when installing or removing or you might find yourself with a broken arm. (if you move it around when it's on the ram will shoot out)
unfortuneately there is no way to activate it in the event the tow vehicles brakes fail.
It's an odd contraption but does the trick.
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Correct me if I am wrong, but I believe there is a difference in regulations if you are "trippling" with 2 bumper pull trailers and one goose neck trailer and one bumper pull trailer. I can't remember why or where I was reading about it being legal to pull a gooseneck with a bumper pull trailer, but I am very sure there was a difference in what was legal and what was not.
Thats a good point. Tripling is only allowed if the first unit has a 5th wheel pin type hitch. Gooseneck beans and 2" reciever style rear frame mounted hitched don't qualify so I don't see how it could be done legeally with a motorhome as a tow unit.
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Trailer brakes are a requirement over 3500lbs...
Trailer brakes are required on all trailers 3,000lb and over in AB and I believe it's 2,000lbs and over in BC.
If you look at the GVW on most single axle (non-braking) trailer it's typically 2,990 lbs yet the trailers have 3,500lb axles.
Vince
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the law does state 910kg (2006 lbs) and up for trailer brakes, but there is exceptions when trailer does not exceed 50% of the weight of the tow vehicle. For this reason most manuals and ratings are based on trailer brakes only been commonly found on 3500lb axles.
In short there is always exceptions.
Trailer Exceeds 910 kg and Weighs More Than 50% of the Towing Vehicle Weight
BRAKES ARE REQUIRED ON TRAILER
Trailer Does Not Exceed 910 kg and Weighs Less Than 50% of Towing Vehicle Weight
and Consists of a Single Axle
BRAKES ARE NOT REQUIRED ON TRAILER
Trailer weighs more than 910 kg and is Less Than 50% of Towing Vehicle Weight
BRAKES ARE NOT REQUIRED ON TRAILER
check out.:
http://www.transportation.alberta.ca/Content/docType41/Production/recvehtowguide.pdf
I build and spec truck equipment for a living and have learned that the best way to know what is legal and not, is to check with the person writing the ticket. (being safe and not getting fined is the concern right) I therfore have the balzac scale on speed dial and they have always been very good at answering any questions that i may have. I also carry a 3 ring binder of the laws on load securement with me when trailering my jeep, as i have seen people fined for 2-4 chains with binders and also with wratchet straps both rated to ecxeed load. The laws for hauling automobiles differ from equipment (go figure).
Balzac scale 403-226-0168
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http://www.th.gov.bc.ca/cvse/vehicle_inspections/PDF/MV3230.pdf
http://www.th.gov.bc.ca/cvse/references_publications/trailer_towing_info_sheet.pdf
The provincial site for BC is full of errors tonight...
and
BC is actually 1400Kg and 50% of tow vehicle for trailer brake requirement
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My TJ has a towing capacity of 2000lb. I have lots of power to tow our 1500lb trailer but loaded with gear the trailer is closer to the 1800 mark. However, the TJ with 33” tires and a lift stops like crap. It also pushes the back of the lifted TJ with a short wheelbase around when stopping. With the trailer breaks now working properly towing the trailer is way better. Stops well and don't feel the back of the TJ moving around as much.
What are the specifics on the trailer you want to tow? Which vehicle are you using the new jeep or the old one.
Your TJ will tow most reasonable size tent trailers. But trailer breaks help a lot.
I think your newer jeep may have a 3500lb capacity but I would suggest installing the break controller. Most of the trailers will have e-breaks so might as well use them.
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Just a quick chime in from an ex-trucker.
It doesn't matter what mods are done to a vehicle... overloads, air rides, tranny coolers, electric brakes. By law you still can not exceed manufacture's GCRW.
That's the TJ, fuel, passengers, dog, toys, trailer, and it's load of goodies.
In your case, the 2008 TJ Unlimited (auto) is 3500# trailer weight however a GCRW of 7944#.
Trust me: BC's D.O.T. (Dept. of Transportation) are strict AND really like nailing out of province vacationers - it's hefty cash-up fines. If they even suspect your are close to your limit, they have full right to park you on the spot & put out the jump scales. You could end up being forced to part with your trailer until a suitable tow vehicle is found.
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I also saw someone's reply about BC 'now' allowing doubles/triples.
Not so... DOT still states, passenger rated vehicles & RVs are ONLY allowed to tow ONE unit. Also keep in mind that in BC, and trailer exceeding 1400 kg (3086#) must have active braking on the trailer.
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GVRW is a little misleading, as that figure is the tow vehicle, fuel, passengers, toys, and tongue weight....
And tongue weight is a combination what the manufacture figures what the frame can support (with the correctly matched hitch for said weight) -- ie, 250, 350, etc.
The towing weight (of 3500) is a manufacture 'recommended' max... it can't really be used when adding or subtracting numbers. One can ball park it, by taking GCRW, less curb weight, less max tongue weight = (your shite) & dry trailer weight --- regardless of the numbers, it's best to never get to close to MSR tow rating (of 3500). Sure the vehicle may pull it, but controlling it is another thing.
From experience, I know that no one really adds up the weight of all their shite correctly. Fuel, water, people, toys, and yes... even accessories (like the new bumper & winch that weights 200 lbs more than stock).
It's ALWAYS a good idea to load up with your normal weekend gear, pitch in the family, fill up the tank, grab some coffee, and hit the scales. At least you then KNOW your numbers.