Montana 3400RL owners & LT tires

[TLightning]

Re Irlpguy's post above. The OP is asking a perfectly logical question. He asked about experiences with LT tires on a 3400RL. I have a 3400 with LT tires, and all I did was answer his question...he can take that information and do as he sees fit...his 3400, his decision. Who really needs to read and heed Irlpguy's post are the folks driving over weight trucks giving advice on hauling a Montana, a subject upon which many have limited knowledge...or they'd be driving a different truck.

[Rainer]

I weighed my trailer fully loaded the day I left on a two month trip once around the U.S. Attached to my truck, the trailer weighed 10,420 lbs. That's the only weight I'm concerned with since it doesn't roll down the highway without my truck attached to it. The truck supports about 1720 lbs of the trailer's weight in the truck bed.

Since I have four tires supporting the weight, and yes I know in actuality the weight is not equal, but just for argument's sake I divide 10,420 by 4 and get 2605. That's well within the limits of my 4 - Uniroyal LT 235/85 R16 120/1160 M+8 E-rated tires with a load capacity of 3042 lbs. With my calculator that's 85.6% - good enough for me, fudge factor and all.

Go out and weigh your rig on a truck scale, then make the determination you need.

[helmick]

I had Michelin Rib LT tires on my 3400 for over 50,000 miles, 41,000 on the first set and so far 11,000 on the second set. I have towed all over the US and Canada including the top of the world highway and all the way across the North West Territories on gravel roads. I have never had a flat or blowout since I changed to LT tires. I'm only telling my experience since that is what he asked.

[Rainer]

quote:Originally posted by helmick

I had Michelin Rib LT tires on my 3400 for over 50,000 miles, 41,000 on the first set and so far 11,000 on the second set. I have towed all over the US and Canada including the top of the world highway and all the way across the North West Territories on gravel roads. I have never had a flat or blowout since I changed to LT tires. I'm only telling my experience since that is what he asked.

I see by the specs that that's an E-rated tire. 3042 lbs. weight capacity. Helmick, you've made my day with your personal experience using those tires on your 3400RL, which is similar to my 343RL HC, only yours is 20% heavier.

Thanks!

[Avofarmer66]

I just had Carlisle ST235/80R 16G rated at 3750lb. @ 95PSI. Carlisle move their tire manufacturing to the USA, Tenn. or N.C. in 2009. I paid $1114.00 for 4 tires mounted w/ tax. Looked for recalls of Carlisle tires made after 2010 and found non. I run nitrogen in the tires to keep them cooler and run 92-93 PSI.

http://www.youtube.com/watch?v=7UDHXl95m8Q

Video of Carlisle tires on trailer.

Running out of Barstow CA at 110 degrees last month and had a Marabom!! Goodyear blow left rear-rear got into the water heater and fender skirts some sheet metal.

I check tire pressure at 7:30AM in Williams AZ and pressure was at 80PSI cold. At 1PSI increase for every 10 degrees of temp I figure the tire pressure was at 84PSI when the failure happened.

I would have bought Goodyear G614 rated @ 3750 @ 110PSI for 4 was a little more at $1890.00

[PSFORD99]

quote:Originally posted by Art-n-Marge

I don't think either country would allow that if you have 7,000 lb axles (3500 lbs per wheel), that you are allowed to use tires at less that rating. It happens, because they haven't noticed, but if any LEO just happened to check and find this. They'd pull you over and not allow you to continue until this is remedied.

Remember how some people think? I'm not speeding until I get caught or if I hurt someone. I don't think like that, but know many others that do. Same with weight compliance and equipment ratings.

And yet people still continue to use ,and recommend a tire that is not rated for their axles. All is well until it isn't .

[gkidsdlite]

Everyone trusts E-rated tires on their trucks why question using them on your trailer?

[Irlpguy]

quote:
gkidsdlite wrote:
Everyone trusts E-rated tires on their trucks why question using them on your trailer?

The most important reason we trust LT tires on our trucks is they are not required to carry anywhere near the rated capacity of the tire, and yet people continue to recommend that they use these tires as replacement to a higher capacity rated tire on their RV's.

For instance the rear GAWR on my Dodge is 9350 lbs, the tires are rated at 2833 lbs @ 80 psi dual. That is the rating on the tire, however the truck manufacturers recommended tire pressure is 70 psi, as per the sticker on the door. That reduces the capacity of the tire to 2560 lbs multiplied by 4 and you have a capacity of 10,240 lbs which is well above the 9350 GAWR. It also gives an even larger margin of safety if we were to run the tires at 80 psi.

Put that same tire, rated at 3085 lbs on a 7k axle and you don't have a 7k axle anymore you have a 6k axle with a little to spare. The capacity at maximum psi on an LT tire is barely above the 6k axle rating.

How does it make any sense to replace a tire DOT rated for 3402 lbs with one DOT rated at 3085 or 3042 lbs.

Avofarmer66 replaced his E rated Marathons with Carlisle G rated ST tires, IMHO a much better choice on a heavy RV than an E rated LT tire, and supposedly now manufactured in the US. The "ONLY" drawback is the speed rating of the ST tire. Can't haul your rig at 75 mph with the ST tire.

[Phil P]

Hi

Why are we talking about “E” rated LT tires when many manufacturers make “G” LT tires that will work on theses trailers?

Phil P

[dsprik]

As per the OP: I have a 2007 3400 and I have just switched to LT tires after I blew 3 ST tires on the way north from FL this spring. We are getting readuy to make our semi-annual 1400+ mile trip between N. Mich and Central FL. One of the major problems with ST tires is something we encountered: Good Sam ERS could not find a ST tire when we sat on the side of I-75 in central OH on a Fri night for 3 hrs. Thanks to this forum, we knew what to do. We bought 2 LT tires (for the same axle) and we were on our way. Later this summer we bought two more LT tires for the front axle. We will let you know how the trip goes. We leave in three weeks...

[Irlpguy]

quote:Originally posted by dsprik

As per the OP: I have a 2007 3400 and I have just switched to LT tires after I blew 3 ST tires on the way north from FL this spring. We are getting readuy to make our semi-annual 1400+ mile trip between N. Mich and Central FL. One of the major problems with ST tires is something we encountered: Good Sam ERS could not find a ST tire when we sat on the side of I-75 in central OH on a Fri night for 3 hrs. Thanks to this forum, we knew what to do. We bought 2 LT tires (for the same axle) and we were on our way. Later this summer we bought two more LT tires for the front axle. We will let you know how the trip goes. We leave in three weeks...

Dave you don't indicate if the tires you blew were original or not. If they were the ones that came on your unit, then they were a minimum of 5 years old and were at the end of their life expectancy for an ST tire. If I get 5 years out of my truck tires I think I have won a lottery.

In emergency situations LT tires will be much easier to come by than ST tires, however I would suspect your 3400 has 7k axles on it and the original ST tires on it would have been rated for 3402 lbs and very likely the GAWR of the trailer axles on your trailer sticker is 6750 per axle. Now, with your LT tires rated at 3042 you no longer meet the rating of the axle or even it's reduced GAWR on the sticker.

The choice to change to LT tires is made by quite a number of members on this forum, many report having traveled extended distances without issue, however I question the wisdom in reducing your carry capacity of your 7k axles by using them.

[Irlpguy]

Dave I just noticed in another thread that your axles are 6k not 7k, the change to LT tires is far less of a factor in that case. At least you are over the rating of the axles.

[bncinwv]

Dave's rig has 6000 pound axles, just as our 2007 3400RL did. The LT's match the axles.
Bingo

[dsprik]

Thanks, guys! Yes, Ed. Our axles are 6K We do not have the drop basement in the 2007. I think that's when they went to the 7K axles. My tires are rated differently though. While the Mastercraft Load range E are 3042# @ 80#, same as my original Missions - which you are right - they were at the end of, or past, their lifetime (I just read and article from a tire maufacturer that stated trailer tires had a life expectantcyh fo 3-5 yrs), my Carlisle tires on my front axle are load range E with 3525# load cap @ 80#. All tires are 235/85-16. I have never heard of a load cap of 3525#.

[Irlpguy]

quote:Originally posted by dsprik

Thanks, guys! Yes, Ed. Our axles are 6K We do not have the drop basement in the 2007. I think that's when they went to the 7K axles. My tires are rated differently though. While the Mastercraft Load range E are 3042# @ 80#, same as my original Missions - which you are right - they were at the end of, or past, their lifetime (I just read and article from a tire maufacturer that stated trailer tires had a life expectantcyh fo 3-5 yrs), my Carlisle tires on my front axle are load range E with 3525# load cap @ 80#. All tires are 235/85-16. I have never heard of a load cap of 3525#.

I am confused here Dave, The Mastercraft tires on one axle appear to be LT tires, however the Carlisle on the other axle are an ST Radial tire. They appear to be the predecessor to the new load range "E" ST235/85R16 Radial Trail RH tire which is rated at 3640 lbs @ 80 psi. They also make a load range "F" tire rated at 3960 lbs @ 95 psi.

If I am correct then you have one axle with ST tires and one with LT tires. Not sure that is the best combination. The ST rated at only 65 MPH compared to likely 95 or 105 on the LT's.

Carlisle does have some strange load ratings when compared to other ST tires but I don't think they even make an LT tire.

You might want to check the two letters preceding the 235/85R16 on the Carlisle's.
I am a long way from a tire expert but I don't think I would want that combination of tires and load ratings that you now have.

[dsprik]

I will double check. I thought they were LT. Hope they were. I really didn't wany to mix LTs with STs, even if they were on the same axle.. I'll ley you know.

[richfaa]

DAVE. I thought your 2007 had 7K axles. My 06 3400 had 6 axles and yours built just a few months later I thought had 7K axles...Check that out,

[Chip]

Yes,

My 07 built in 06 had 7000# axles.

[dsprik]

quote:Originally posted by richfaa
DAVE. I thought your 2007 had 7K axles. My 06 3400 had 6 axles and yours built just a few months later I thought had 7K axles...Check that out,

I did crawl under and checked,Rich - a couple years ago. They were stamped "6K". I can double check that too, but it/s raining here right now and I really don't wany to crawl around in the mud. I am sure they were "6K". I believe they changed to 7K just after my 3400 was built.

[richfaa]

The Keystone web site list a 2007 3400 having a GVWR of 15,500 lbs.That is 7K axles.My 2006 3400 is listed as 13,975 that is 6K axles. Take a look at your tag on the side of the rig. If it says 15,500 lbs GVWR you have 7K axles. If it says 13,975 you have a 2006 3400. I know you have a 2007 ? because Helen and I went to the Dealer and looked at it when it came in before you did and there were different things on it like the interior trim. You either got the wrong axles or the wrong year rig.