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Re: Double axle feedback
Posted: Wed May 26, 2010 8:10 am
by curtiss
My original trailer came with a single torsion bar type axle without springs. I just added an second additional standard torsion bar axle. I didn't investigate the style you have described. It looks like it would be nice. Two things come to mind for a conversion of the original aluminum trailer on the 26M as you describe. It might be more expensive as it looks like you would have to buy a completely different type of axle set up. Second, from the description it appears that it might raise the height of the boat from the surface of the road/ramp. Maybe you have more information on these issues. In any case I didn't compare the two as I was unaware at the time of the type you described. This is great information so the next Mac owner that wants to convert has more choices to explore.
Curtiss on LaVida
Re: Double axle feedback
Posted: Wed May 26, 2010 8:10 am
by Sumner
Hamin' X wrote:.....For tandem axles with individual springs, an equalizer arm is used as a common spring hanger between the axles. Example:
...................~Rich
I call them equalizers also, but mine (the middle one in the picture below) .....
...aren't as fancy as the one's in your picture
,
Sum
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Re: Double axle feedback
Posted: Wed May 26, 2010 8:33 am
by raycarlson
After 40yrs of using the old leaf spring axles I have seen the light and will be using torsion axles from here on.As far as the new mac trailers go with single or tandem axles its like having 4 wheel independent suspension, a bump on one wheel transmits no force or energy to any of the other wheels, also there are no hangers,equalizers,bolts or bushings to keep lubed or worry about rusting.cost is also less, and installation is simple as it can get.I have never had a smoother running trailer(i do have tandems though) than this one, I only question its longevity as far as wear on the eight rubber slugs that are used for torsion resistence,however they do look easy and cheap to replace.I have three years on them now if they go three more i will be happy,and find out just how easy it is to replace them.
Re: Double axle feedback
Posted: Wed May 26, 2010 3:29 pm
by DaveB
Bob, I think the walking beam has the springs located above the swing beam pivot point and raises the boat to much for launching.
The system I have is a Swing arm that both Springs attach to a casting of a semi Triangle were the center of this triangle is attached to frame and leaf springs attach to each end.
I towed my single axel Potter 19, 2200 lbs over a very lumpy Old 41 from Cape Coral to Keys (250 miles+) and bounced most of the way.
I tow my Mac.X 4500 lbs and hardley feel it behind me on same road,useing same truck (1999 F150, 6 cylinder extended cab, standard trans. Tow 2000 lbs max. Cap.)
Dave
bscott wrote:Dave, according to the guy that installed my second axle, your swing arm is called a "walking beam". We also installed an axle assembly sliding angle iron which we can move the entire axle assembly fore/aft to get the best weight distribution-it also beefed up the frame. With air bags in the rear Jeep springs I can level the trailer=no sway at 70 mph. No more gas cans in the bow
I was going to replace my Jeep with a 3/4 ton PU for a better tow but the trailer/Jeep mods work so well that I will keep the Jeep for another 50,000 miles and save the cost of a new truck.
Bob
Re: Double axle feedback
Posted: Wed May 26, 2010 11:44 pm
by Seafarer
Hardcrab wrote:curtis,
Thanks for the info.
My 2005 Tacoma 4X4 sounds very close to your Explorer as a minimum sized tow vehicle, also IMHO.
A couple of questions.
Did you do it yourself or pay to have someone do the work?
If you did it yourself:
Where did you source the second axle?
Axel cost?
How did you do the surge brake issue?
What measurements did you use for locating them?
If you paid someone else, can you provide insight to any of the above?
Where did you get it done, if that's the case?
--------------------------------
My 26x axle failed totally (likely a dried out bearing) so I decided to upgrade to dual axle while fixing it.
I pretty much did everything myself, except for the welding, which I took to a local weld shop.
First ordered a set of brand new axles from Champion trailers using using similar dimensions from the stock Mac trailer. The new axles from Champion trailers are better than the ones that come with the Mac as they have a hollow channel inside the steel where bearing grease can be injected right into the bearings - you never need the annual bearing repacking with these.
Next I ordered four sets of disc brakes to replace the 2 worn out drum brakes that came with the trailer.
Also had to get a new surge brake cylinder and reverse solenoid : both are needed when you convert from drums to disks.
Also got an extra set of leaf springs, all from Champion Trailers (excellent source and very knowledgeable staff).
I installed one axle as far forward of the existing mount point as possible. And the second one, behind the existing mount point. Though close enough to retain the origin fulcrum, the mount points were not exactly the 50:50 forward/aft of old mount point due to the fact that the 26x trailer begins to taper inwards shortly beyond the existing mount point as you go forwards towards the tongue.
I had the welding for the leaf spring mounts and surge cylinder done at a weld shop, but the rest I did myself, including mounting the disc brakes, running new hydraulic lines, and bleeding the system.
Results:
Pro: Much more stable system. Braking is far far superior with 4 disc brakes vs 2 drum brakes. No sway.
Con: harder to swivel into nooks (used to back the trailer into a corner, disconnect from the car, then swing it sideways by hand to swivel the trailer right into a side corner. Impossible to swivel by hand with the dual axle).
Also going downhill, the brakes are too good! they will heat up if the tow vehicle is going at speeds less than a free fall.
Overall: I am very pleased with the upgrade.
Braking alone is such an improvement - I feel it greatly extends the life if the tow vehicles brakes too. For long downhill stretches I manually control / disable the disc brakes by wiring it to my lights which I can control easily.
Lottsa questions, sorry.
I'm considering the same move and hungry for any/all info beyond the "why".
Re: Double axle feedback
Posted: Fri Jul 30, 2010 5:35 pm
by Starscream
I just added a second axle to my '02X trailer. Had it done at a trailer shop locally, with all parts and labor it came out to $1,100.00 CDN, and this included adding another cross beam between the nose bunk and the first body bunk for some additional stiffness. Maybe I'll add another bunk on the new support later on. After one hilly trip, I can confirm that as expected it's much, much more stable. It doesn't swing left-to-right nearly as much, and even the up-and-down bouncing has been greatly reduced. It adds a great deal of peace-of-mind as well. I had a blowout on the highway last year on the single axle, and while it actually wasn't a very dramatic event, once the spare is on you're out of spares and the stress level skyrockets if you're any distance from home.
One problem though, my fuel mileage has taken a big hit with the dual axle. Where I was averaging between 16 and 17 L/100km...something like 14mpg, I guess...with the dual axle I'm now averaging about 21 L/100km. I had the shop check out the installation, alignment, and the brakes, but everything was in order. Hard to believe the rolling resistance of a second set of tires is the culprit...anyone else had a similar experience?
Another bonus is that the rattling of the trailer suspension as it goes over small bumps is gone. It used to sound like a tin can full of BB's.
And, it just looks better. Less like a toy, more like a boat trailer.
Re: Double axle feedback
Posted: Fri Jul 30, 2010 10:03 pm
by Sumner
Starscream wrote:.............One problem though, my fuel mileage has taken a big hit with the dual axle.........anyone else had a similar experience? ....
Are you driving any faster since it is more stable. Just running 4-6 mph faster than you use to could account for the decrease in at least some of the mileage difference. I would think the added weight would have more to do with it also vs. rolling resistance. This would be especially true if you are encountering start and stop mileage where the weight has to be accelerated up to speed over and over, but not so much if you are talking a steady mph going down the road.
We will know soon what difference a second axle makes in our case. I hope it is not as much as what you are reporting. Here in the mountain west usually at 5000 feet or more we average 11-12 mpg pulling the boat with a low of 10 something and a high in the 13's. That was pulling about 5000 miles last year. This is with a '99 5.7 liter vortec V-8 Suburban usually running about 60-65. Without the trailer we get an average 17 mpg, but don't use it much other than to pull the boat.
c ya,
Sum
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Re: Double axle feedback
Posted: Sat Jul 31, 2010 12:32 pm
by DaveB
Sumner,
I have been running my Mac. X with weight includeing trailer 4500 lbs. I have a tandum aluminum trailer I had built for $2900 2 years ago and added a $500 stainless steel disk break system to front axel.
My truck is a 1999 Ford 150 extended cab with 4.2 liter 6 cylinder and max. towing is 2000 lbs with the Standard 5 speed trans.
I have gone thru 1 clutch,bell houseing with pressure plate after 11 years of towing well over 2000 lbs. on all my boats.
I haul my Max.X to the Keys and back over 600 miles with no problems.
Getting back to the Tandum Trailer I got between 11-12 gal. mpg pulling the 4500 lb Mac X. I normally get 15-16 mpg. around town and 21 on highway ,no trailer.
I admit the standard Trans is not designed to do back ups over hill and grass but other than that works fine and no sway at 60-65 mph.
If I didn't have to back my boat up and over a 4 ft. swell to get in my back yard than even my truck could do good for people who don't have to climb hills.
Are you driving any faster since it is more stable? Just running 4-6 mph faster than you use to could account for the decrease in at least some of the mileage difference. I would think the added weight would have more to do with it also vs. rolling resistance. This would be especially true if you are encountering start and stop mileage where the weight has to be accelerated up to speed over and over, but not so much if you are talking a steady mph going down the road.
I still feel by adding additional axel and weight would off set the Milage by equilizing the load on 4 tire instead of two. Also the safty factor if you have a blow out.
There also more maintance but thats min. and do front axel same time as rear.
Dave
We will know soon what difference a second axle makes in our case. I hope it is not as much as what you are reporting. Here in the mountain west usually at 5000 feet or more we average 11-12 mpg pulling the boat with a low of 10 something and a high in the 13's. That was pulling about 5000 miles last year. This is with a '99 5.7 liter vortec V-8 Suburban usually running about 60-65. Without the trailer we get an average 17 mpg, but don't use it much other than to pull the boat.
c ya,
Sum
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Re: Double axle feedback
Posted: Sat Aug 07, 2010 7:11 pm
by Starscream
Ok, I just returned from a week's boat vacation on Reservoir Baskatong in Quebec, about 200 miles northwest of Montreal. I'll post a report about the trip a bit later. Check out
www.pointdavid.ca to see where I went.
I lost one of the new fenders on the trailer on the way back, the weld snapped and dropped the fender onto the tire. Good thing it was still light out when we left or we wouldn't have seen it and it would have worn through the tire real quick. Just after less than a minute or of rubbing the fender and tire were super hot. I may have hit the fender as I was getting the boat onto the trailer in a high crosswind...at least I hope that's why the weld cracked and not shoddy workmanship. Note to self: if I ever consider leaving a tool behind in the future, don't. I left my heavy tin snips on the garage floor thinking that the chances that I'd need it were low. Nope. It took a long time and some cursing to fatigue the metal on the side of the fender that was still connected to the trailer enough to get it off.
Other than that, it was the smoothest trip. It was really hilly, with some grades up to 10%. It was nice to just let the truck roll down at its own speed and not have to brake to keep the trailer at a stable speed. Anything over 105 km/h used to be really scary, but on this trip there wasn't a hint of instability. We passed big logging trucks, went through a really windy thunderstorm, over some really bad roads, and not a creak, groan, rattle, or sway from the trailer. In this respect, the dual axles were some of the best boat bucks I've spent.
On the fuel economy scale, we averaged 11.5 mpg both ways. A/C was on most of the trip. Of the 3.5 hours on the road, about an hour was at 100 km/h on a good two-lane highway, about a half hour at 60km/hr on a backroad, and the rest at 80-90 km/hr on a single lane highway.
I'm pretty certain that the fuel economy is due to the change in the trailer. The whole affair seems to slow down faster and resist acceleration more. Searching my memory, it's possible that it may not be as bad as I think. Towing the boat from Hamilton to Montreal last year on a relatively smooth and level highway I was averaging something around 15 mpg without A/C. And I'm reassured by all the other posts of around 11-12 mpg.
So my verdict on the dual axle: DO IT. The peace of mind was worth every cent.
Re: Double axle feedback
Posted: Wed Aug 11, 2010 1:48 pm
by Catigale
I've posted here that with my 200 hp Eurovan I saw no diff on mpg (13 mpg recorded) at 55mph or 65mph
This was measured with a Harrison engineering OBD software package over 75 miles or so
I tow at 60 mph where life is simple and good.
Re: Double axle feedback
Posted: Wed Aug 11, 2010 9:20 pm
by Phil M
Catigale wrote:I've posted here that with my 200 hp Eurovan I saw nod diff on mpg (13 mpg recorded) at 55mph or 65mph
This was measured with a Harrison engineering OBD software package over 75 miles or so
I tow at 60 mph where life is simple and good.
So what is 'nod diff' on mpg?
Phil M
Re: Double axle feedback
Posted: Thu Aug 12, 2010 6:40 am
by Catigale
Sorry - Iphone post and I was all thumbs....edited for clarity..
nod diff should have been no difference
Re: Double axle feedback
Posted: Thu Aug 12, 2010 10:07 am
by bscott
I get 11-13 with a 4.7 V8 at 5,000-10,000' alt. with my tandem. No A/C on up hills, yes A/C down. I remember +1 mpg when trailer was single. No way would I ever go back to single on any load exceeding 3,000#
Bob
Re: Double axle feedback
Posted: Wed Jun 15, 2011 3:24 pm
by RobertB
My current tounge load is between 300 and 400 pounds with the single axle (variation is loading and how close the boat is to the front of the trailer, have not yet experimented with Mac-bumps yet). What has been the change in tounge loading with a second axle and does this afect trailerability? I would like to hear that the loading is less with no ill efffects - better on the suspension of my car.
BTW, I have the new aluminium axle with brakes.
Re: Double axle feedback
Posted: Thu Jun 16, 2011 3:53 am
by c130king
I just bought a new double-axle trailer. The manual says 5-6% tongue weight. My old single-axle Mac trailer was at 10% (or close to it).
So apparently you don't need as much tongue weight on a double-axle trailer.
Cheers,
Jim
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