Twitchy steering with a big travel trailer (rear sway bar help?)

[AuroraGirl]

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go read my previous posts, still waiting on photos of your steering linkages/geometry and question about alignment...

I also brought up power steering related things that could be in play here too

 

[Grit dog]

arr you measuring the trailer and truck on this scale? thats.. .a heavy trailer for such light payload

If it is, subtract your trucks weight (4-5,000 pounds id take it?)
Still heavy but changes things considerably

Huh?

 

[Grit dog]

Thanks for the response. The empty weight on the trailer at the scales was around 8600. Im assuming that we probably add 1000 pounds once loaded but I need to verify this. Typically my tounge weight measures in between 875-950 pounds based on the tongue weight scale I have. Once this is set, I then have to adjust the weight accordingly to the weigh safe app via the hitch adjustment.

Based on your posts after this, idk if the steering has anything to do with the trailer. But assuming you know your tongue weight which seems you do, I cannot begin to understand how you can need 60psi in the bags. Or even 1psi. Unless you have 20 sacks of concrete in the back of the burb.
1000lb tongue weight, transfer say half of that with a wdh. That’s like the weight limit of 2 large men sitting on the tailgate. Shouldn’t budge a set of 3/4 ton leaf springs hardly at all.

 

[Grit dog]

OOO. So I probably have too much pressure in my 2005 gmt800 tires? I Think with the warming up they are probably 55psi
BUt 48-53 when it was cooler , while i have at max 300 pounds in the bed/cab and no spare tire


We talking the sidewall spec? Isnt that a little above the safety limit? assuming the tire is saying 50-55psi max, that is. If youre going by what the label says on the truck then nvm



this is a very good question too
While i dont think the tires are a small part of it all, Im glad you agree there is more components and factors than the tires. I think just saying a new set would fix it is being a little too optimistic, esp since that could be a great cost depending on how he decides to get them

I was talking air bag pressure. But yes if you’re running 50psi or more in the rear tires of and empty pickup truck that is fine other than way more than needed. Rides rougher and worse traction. Look up a load pressure charts for your size tires and compare to the 2500/3klbs rear axle weight on your empty truck. Probably 25-30psi is min sufficient pressure. Adjust from there to preference.
As far as overfilling tires. No, not per any spec and not advisable publicly. Just saying it works. Evidenced by having many half tons that got used well over their published payloads and P or XL tires.
And for the record I was sayin the tires are likely not his root cause of the issue. But he spent more on rims than 2 sets of those tires would cost so cost anit really a huge factor if the tires needed replaced.

 

[Grit dog]

I'd suggest getting a second set of rims and wrap them in E rated tires for when you are going to tow. Then run the passenger setup when you want to have your passenger car back.

Easy to test the necessity of that before buying new wheels and tires.

 

[Grit dog]

If the tires have/had uneven wear you might be experiencing some tread pull too.

My tire guy recommends an X pattern rotation for trucks. Not sure if other rotation patterns would be better or worse, but I trust his judgment.

To that point, the best rotation is the one that keeps the treadwear even. Which barring alignment issues or correcting uneven tread depth is typically straight front to back. Because front tires feather or cup one direction and rear tires the other direction. X pattern doesn’t correct feathering or tread cupping. JMO. 90% of rotations I do end up being just front to back. Even more important on big at and mt tires

 

[Grit dog]

Tread pull meaning down the road? actually goes pretty straight. the tires are old (16 and 17 for year)
And the front tires are above minimum tread but below good traction

The rear have a lot of life (10-15k if i was really trying to squeeze the life from them)
my step dad DID NOT rotate or keep the pressures up sufficiently when he used it all the time before getting his 14 2500hd

So my rear tires before winter had very much more wear. I had swapped tires side to side in the front when I fixed my brakes last fall (exploded piston, almost wore one side of rotor) and then when I lubed all the brakes after doing brake lines and fixing my stuck parking brake shoes I did the fronts to the rear, and then backs to front (since they were swapped side to side not even 2k before that)

I just drove it this morning with equal pressures all around (i must air my driver front all the time, babying it a bit to save money,) I want to get them rebalanced when i repair the leak. needs a valve stem.. anywho, i just drove it and it goes straight with the wheel, but a month or 2 ago I noticed that with bed weight the front becomes a little wiggly

The definitive solution here is a decent set of tires. And maybe some front end work. Not sure how this relates to a totally restored squarebody and a trailer.

 

[txaggie]

I was talking air bag pressure. But yes if you’re running 50psi or more in the rear tires of and empty pickup truck that is fine other than way more than needed. Rides rougher and worse traction. Look up a load pressure charts for your size tires and compare to the 2500/3klbs rear axle weight on your empty truck. Probably 25-30psi is min sufficient pressure. Adjust from there to preference.
As far as overfilling tires. No, not per any spec and not advisable publicly. Just saying it works. Evidenced by having many half tons that got used well over their published payloads and P or XL tires.
And for the record I was sayin the tires are likely not his root cause of the issue. But he spent more on rims than 2 sets of those tires would cost so cost anit really a huge factor if the tires needed replaced.

I have an endless supply of these pirelli’s based on what I do at almost no cost.

 

[Grit dog]

what kind of tires is the camper using?
And an idea i just had
While pulling it, manually apply the trailer brakes just a bit , does this improve or not change the issue?

He never mentioned trailer sway although good point/reminder. Easiest way to correct trailer sway typically from not enough tongue weight (which is not the Ops issue) is applying trailer brakes while accelerating.

 

[Grit dog]

Driving it home tonight even without a trailer I can feel the light twitch in the steering. It’s almost like it tracks and darts quickly from one side to another in a short amount of steering wheel turn but drives straight down the road. Maybe I need to look at my alignment.

As all is tight and new according to you, you may not have enough caster in the front end. Less caster = twitchy. Too much caster = heavy steering but tracks very straight. (Sort of. Not the full description). Seeing how you redid everything on the front, maybe caster angle is shy of what’s specified.

 

[Grit dog]

What I meant was that it was brought up that the tires in question should be up to the task as far as the ratings go. But sufficient tires are never as comfortable as more than capable tires.

In short, I'm in the same camp as many of the original posters- the tires aren't meant for what they are being used for and are very likely the cause of the "twitchy" steering.

Possibly. Although I’m not seeing 5klbs on the rear axle without the OP explaining why he’s using airbags to that extent or at all.
Nor am I seeing it possible to have anywhere near enough weight in the rear axle especially if the wdh is pulling any weight off. Those bags at 60psi will jack the truck up in back above empty ride height even with no wdh.
More needs to be verified before blaming the tires.

 

[Grit dog]

I have an endless supply of these pirelli’s based on what I do at almost no cost.

That’s cool! Also I was replying to @AuroraGirl post about her truck and tire issues or whatever.

 

[DoubleDingo]

Easy to test the necessity of that before buying new wheels and tires.

True, borrowing a set from someone should be somewhat easy if there is a friend or coworker with a set to borrow from.

 

[Grit dog]

The speculation in this thread has turned into a bit of a mess.
I’d say do this.
1. Front end alignment. Specifically caster.
2. Figure out your actual rear axle weight loaded. Then you can confirm or deny tire load rating. And you can test higher pressures for a practical verification whether stiffer rear tires help.
3. Figure out the cluster of wdh and waaaay too much airbag pressure. You still haven’t provided any justification for that. But you 100% are not doing something right when it comes to that.

 

[DoubleDingo]

Possibly. Although I’m not seeing 5klbs on the rear axle without the OP explaining why he’s using airbags to that extent or at all.
Nor am I seeing it possible to have anywhere near enough weight in the rear axle especially if the wdh is pulling any weight off. Those bags at 60psi will jack the truck up in back above empty ride height even with no wdh.
More needs to be verified before blaming the tires.

If the tires are not up to task, and the tail is wagging the dog, wouldn't it cause the "dog" to be squirrely? If the front suspension that was swapped in is not 3/4 ton suspension, that may be a contributing factor, and the different control arms, if not factory replacements, may not be geometrically correct for heavy work. His rig looks great being lowered, but it may not be a 3/4 ton anymore.