Darryl&Rita

I'm scratching out the ideal tow unit for an RV purpose, and am running into some questions regarding turning radius/cargo capacity. I would like to deck the unit, to carry a TJ Wrangler Unlimited. I'm thinking that the rear axle could be moved into place of the power divider axle, and a new, gutted housing placed in its' place. This new rear axle would be set up with an air lift setup, to decrease turning radius when running empty, or in tight quarters. I think this would be benificial for drivability and tire scrub issues. Any body got any flasbulb moments or "don't do it because..."

1-5-3-6-2-4

if you have tandems even if 1 is technically a tag you'll need a class 3 license. if its a straight 2 axle truck even with airbrakes you can us a class 5 with Q endorsement.

a class 8 with a the rear diff removed will still be around 22,000lbs capacity. if you start with a regular 44,000lb tandem.

Just K.I.S.S. method................ keep it simple stupid.

DmaxEter

I have seen several mail haulers that run a setup just as you described. No need in having that extra drag and wear and tear of a second driven axle if you dont need it. The ones I see usually set it up with a rear rear drive axle and then install a drop axle just ahead of that to make it a tandem. You couldnt tell the difference unless you knew what to look for.

wannadiesel

If you do it use a drop axle instead of cobbling something out of old parts. It'll be more reliable and weigh less.

Darryl&Rita

Good point. I'm trying to keep turning radius down, that's what's driving the rear tag location. This location seems to scare people away from this project. I guess I'll have to go get my class 3 to drive a tandem, as an Alberta class 1 apparently won't work(Notice I wasn't asking how to drive it, I was asking for feedback and insight)

DmaxEter

There is nothing wrong with a tag axle behind a drive axle. I see those regularly as well behind a tadem setup. Your idea sounds good and will work. There are tons of trucks that use tags like you have described. Lots of garbage trucks do. If it holds up on a garbage truck, you will never have a problem out of it!

http://farm4.static.flickr.com/3384/...a3a408819c.jpg

http://www.chassisengineeringltd.co....09_1_large.jpg

sshewins

I think it would be reliable and safe if it was done right.

wannadiesel

X2 I didn't mean to imply there was anything wrong with the configuration you wanted to build. I just didn't want you to try to re-invent the drop axle working with junkyard parts when you could just buy one that would be lighter and work better.

1-5-3-6-2-4

you
me
do you really need tandem capacity? really? to put a jeep on............




I'm sorry, my crystal ball must be broken. I didn't know you R truck driver. I R truck driver class 1 too. well after being Redseal H.E.T. and Licenced CVIP inspector I guess.

if you need need need to have a tag why don't you just buy a tractor with a 3rd axle tag and move it to where ever you want it. seems ike every 3rd tractor running in Ontario USA is setup that way.

MCI and Prevost busses have drop tag rears on most models. lots are automatic steering tags . the MCI model E Renaissance has a closed circuit hydraulic assist steering tag. go pilfer one.

what do I know though I'm just a stupid mechanic.

Darryl&Rita

From what I've been reading, front axle weight starts to become an issue with a singled truck. I never even thought of a specific axle set-up for tag duty, so that was the intent of this post. In addition to the deck and load, an air ride hitch will be set approx. 40 " back of axle centerline, hauling a 5th wheel with around 3000 lb pin weight. This is a similiar set-up to what several others are running on escapees.com, I'm just fishing for more input.

1-5-3-6-2-4

I don't know the math on your intended geometry there with the hitch. but I just dont see how you're reaching 12,000-14,000lbs on the steers> your GVWR is still 32,000-34,000lbs with a single. with a 12-14k on the steer.


I'm not trying to kill the dreams or anything. but why go through the hassle and extended fabrication to move a tag or build a dead 2nd axle like you were thinking. dropping the rear drive is easy, right. and if you need the extra load Cap keep the 2nd drive. you don't need a sleeper so a day cab shortens up the W.B. considerably already. I really don't think you'll gain in turning radius what I would consider worth the effort to do it. if your going to be turning so tight so often that you're really worried about tire scrub. then maybe a tractor isn't really what you should be looking at for the project.

but I do full understand the need to tinker and build dont' get me wrong. but I think sometimes theres a point of too much in for not enough gain. lay a nice aluminum deck on a nice daycab with a 10-12L engine and let 'er buck. Of course thats just my opinion.

1-5-3-6-2-4

or why not get a freightliner M2 sportchassis like this and mod the deck. these are niiiiiiiice inside. leather everything. and a shorter wheelbase. I don't recall what the GVWR on these are but dang they're nice.

actually if some ones good at enlarging pics the dot decal is right in front of the Pass side tire.

1-5-3-6-2-4

heres an MCI drop tag with the engine and tranny removed you can see the hydraulic cylinder on the frontside. I can try to get better pics of it tommorrow if you want. its got air disk brakes and everything.

2006Mega

go over to escapees . com for more info on your planed RV. lots of people that take over the road trucks and extend the frames, carry a jeep, drop an axle and then put the hitch for the 5er 3 ft back from the rear axle.

1-5-3-6-2-4

I can see that being the easiest way for sure.

heres your standard day cab. you're 145" WB to the 1st drive and 200" to the 2nd drive. you could drop the 1st drive. push the frame. get jeep on and hitch and still have a pickup truck-ish wheelbase.




heres the 1st google pic I found of a tandem + tag tractor daycab