Towing Wander.....

[ramduk]

I have a 2012 Ram Mega Cab SRW with around 75000 miles. I tow a travel trailer that weighs around 11,000 with a hitch weight of around 1,400. I use a E Qual I Zer weight distributing hitch. I have towed this combo for 10 years. I just replaced the tires on the truck with Mich. Defender tires. The same tire that was on previously. The shocks are original and I plan on replacing them.
On this trip I would experience slight trailer sway when passed by semi's which would transfer to the truck causing the front end to wander a bit. This never occurred previously. Previously I would get a little sway in the trailer but it did not affect the truck. The truck feels "light" in the front end. It is pretty much used exclusively to tow. Truck is stock with no lift and stock tires. Any suggestions.

 

[Ozymandias]

How many miles on the new tires yet?
I ask because they need some time to break in.

 

[petersonj]

Make sure that your tire pressure for each axle matches the weight carried for each axle (including the trailer) - very easy to overlook. I recommend weighing and recording the weight of each axle for the load you are carrying if you haven't done so already.

I have heard people refer to what @Ozymandias mentions as "tire squirm" which can occur with new tires. I personally have never experienced this situation, but I am certainly not saying that it doesn't exist.

In 2015, on a return trip from visiting the east coast, I stopped in El Paso, Texas and replaced all four Michelin LTX tires with another set of the same. I asked that the front tires be aired to 55 psi and the rear tires to be aired to 50 psi. (I was pulling a travel trailer with gross combined weight of 12,500 lbs - rear axle weight was 4000 lbs).

I left El Paso and for the next two hours of driving I felt exactly the symptoms that you mentioned. Each time I passed a semi, or one passed me, I felt a subtle continuation of sway that was never there before. Tire squirm? I was thinking maybe so. Then I started thinking a bit more about it - Discount Tire (whom I've used for years) has a habit of airing up rear tires to 80 psi. So, I stopped at the next rest area and discovered that this was the case. I reset both rear tires to 50 psi and left the rest area. Trailer sway gone! The rig handled exactly as it did before the new tires.

If it were my rig, the first two things I would check would be axle weights and tire pressure.

- John

 

[ramduk]

Thanks...the tires are brand new and the rear is at 80 and the fronts are at 65. You may have a point. Thanks.

 

[AH64ID]

New tires are known to squirm for a few hundred miles.

If the tires have more than 500-1000 miles on them then I would ensure your trailer weights are still where you think they are. The leading cause of sway is insufficient tongue weight.

Do you know your axle weights? 65/80 psi seems high for the light load of 1400lbs tongue weight.

 

[JackFate]

My first step would be shocks and alignment.
Hope you have someone to trust on alignment.

 

[crispyboy]

I have experienced new tire squirm with both Firestone Transforce AT and Michelin LTX AT2 tires. Both seem to take about 1000 miles for them to be more steady.

 

[ramduk]

The trip was 3000 miles so I would assume the squirm should have worked it self out. I am between Austin and San Antonio so I will need to find a alignment shop and install new shocks. I weighed the truck and trailers some time ago and can't fine the stats.....Based upon the past the trailer runs between 11and 12,000 lbs and the tongue weight was around 1400. I have a camper shell and a load of stuff in the back of the truck along with two folks and two large dogs....

thanks

 

[AH64ID]

The trip was 3000 miles so I would assume the squirm should have worked it self out. I am between Austin and San Antonio so I will need to find a alignment shop and install new shocks. I weighed the truck and trailers some time ago and can't fine the stats.....Based upon the past the trailer runs between 11and 12,000 lbs and the tongue weight was around 1400. I have a camper shell and a load of stuff in the back of the truck along with two folks and two large dogs....

thanks

Try to increase your tongue weight. 10-15% is normal, but 13-15% rows more stable. If your stats are correct you’re at 11-12%, and could be more easily effected by bow wave.

 

[ramduk]

What bewilders me is the change of handling since I last towed. Over 50,000 miles of towing with this combination with no sway. The set up is the same as is the trailer load. When the bow wave hits I can see a slight movement of the rear of the trailer but the front steering of the truck moves more dramatically. I've always used air pressures on the truck at the maximum prescribed on truck 75 on rear and 65 on front. I did find the rear pressure was at 80 on the rear which is the max load pressure on the tire. Only change was new tires on the truck and trailer. I won't be taking another trip for a while so my focus is on an alignment and new shocks......does anyone no of a alignment shop in the South Austin to the North San Antonio area????

 

[Audiowriter]

Give em 500 miles and they will stiffen up.

 

[AH64ID]

What tires did you put on the trailer?

Give em 500 miles and they will stiffen up.

He indicated there are 3000 miles on them, which is beyond what it should take to stiffen them up.

 

[petersonj]

I won't be taking another trip for a while so my focus is on an alignment and new shocks

During your down time I recommend a thorough inspection of the weight distribution hitch. One of the spring bars may be cracked or bent. Check the bores for excessive wear. It is possible to have the correct tongue weight but still not be transferring enough weight to the front axle. This is why I highly recommend weighing the rig.

- John

 

[Cummins12V98]

Thanks...the tires are brand new and the rear is at 80 and the fronts are at 65. You may have a point. Thanks.

WHY are you running 80psi with such a light rear axle load?

Weigh your axles, add 10psi to truck fronts 5 psi rears and 5 psi trailer tires to what the load inflation chart says.

 

[GCroyle]

WHY are you running 80psi with such a light rear axle load?

Need to also consider the gear load (currently unknown) that goes in the bed.

I have the Equal-I-Zer hitch in my Airstream. Might also check the tightness on the bolts for the bar sockets in the head. Any chance to have someone shadow drive you while towing an look at what the rig and hitch maybe doing?

Something that I made for my rig years ago was a set of stainless steel shims that go on three sides of the stinger to receiver. One is a 90 deg and the other on the top side of the stinger. It took ALMOST all of the slop out of the 2" stinger/receiver and calmed my steering wheel down a bit more. The stainless was at hand from a pass door kick plate and its tough stuff. If I ever loose them that's job #1 to make a new set. And no my opinion is those hitch clamps do not have the same affect as a full length shim. I saw the front inside of a receiver that ran one and it was beat up inside.

Gary

 

[Ozymandias]

Shocks and Alignment won't cure the issue as this two things weren't touched and worked well with the old tires. Air the tires down according to the load/pressure chart from Michelin. That will give you a larger contact Patch from the tire to the road.
It is Nonsens to air a tire to Max pressure without the proper load to it, there are only downsides from doing so.

 

[SnoKing]

I have always had to reset tire pressure in the parking lot of the tire store after they fill them to door sticker pressure when I come with an empty load truck and leave the same way. They have never seen an inflation table and corporate says send them out over inflated to the current load.

 

[AH64ID]

I have always had to reset tire pressure in the parking lot of the tire store after they fill them to door sticker pressure when I come with an empty load truck and leave the same way. They have never seen an inflation table and corporate says send them out over inflated to the current load.

I’ve never had a tire store that won’t set the tires to the pressures I ask them to.

 

[ramduk]

All good points to consider. Texas inspection on the trailer is due in April. When I take it in I'll go by the scales. Weighing is a pain in Texas. Have to go to a commercial scale. When I live in Oregon all the scales were accusable when closed to the public. I have my weights listed buy can't find the paperwork. All the suggestions are great. I have them listed and work down the list and work down them before our next trip in June. Thank's again.

 

[petersonj]

I purchased one of these years ago. No more guessing about tongue weight. They make 1,000 lb, 2,000 lb, or 5,000 lb rated scales.

- John