Help with over steering conditions while driving

[beachvic]

I have a 2018 33U Precept, I love everything about it, I enjoy driving with this one exception. I drove from Ohio to FL and back over spring break and my arms were getting sore from the over steering I had to do to keep the MH in my lane. Wind conditions were very bad and trucks passing were the two main issues for my trip! What do I need to do to eliminate or at least minimize how much steering I need to do to go down the highway? I have read many places where people added a Safe-t-steer or a roadmaster shock to help with these conditions. I bought the Safe-t-steer last week. When I looked under my MH yesterday afternoon what to my shocked surprise!!!!!!!!! One had already been put on the MH? Now what do I do? obviously the Safe-t-steer isn't helping enough and now I have to return the one I bought ( hopefully) or find someone who wants to purchase from me! Any ideas are welcome.

[Grumpy]

Check the weight on the front axle. If you have too much loaded behind the rear axle that will make the front end too light and can cause that problem too.

[oldmanAZ]

Was this the first time you had a problem or the first time you drove it in the wind?

I'd start with your tire inflation pressures. A few years ago I had a small MH. There was a 'sweet spot' for the front tire pressure; too high and the steering was 'twitchy' and too low and the unit would wander.

[Eddy]

Jayco install J ryde suspension and steering upgrades as standard on Ford Chassis , so the issues are more likely to be weight distribution as already posted.
Ed

[Vicr]

Originally Posted by Eddy

Jayco install J ryde suspension and steering upgrades as standard on Ford Chassis , so the issues are more likely to be weight distribution as already posted.
Ed

The "J Ride" suspension is nothing more than a marketing ploy by Jayco. Everything "J Ride" comes on the F53 motorhome chassis supplied by Ford.


OP. As far as wind goes and helping the "tail wagging the dog" when semi's pass, have a rear track bar installed.

[hawkster]

Try getting an alignment at a large truck shop to Ford motorhome specs (different than chassis specs as unit is supplied to jayco). I am adding the track bar also for symptoms you describe and will report back in a few weeks after I have driven in wind.

J ride plus is b.s.

[Foretm]

Lots of good suggestions here. Here's what I did in order. Not saying this is the best order, but this is what I did.


Free

- Weigh the coach and adjust the tire pressure. The goodyear tire chart minimum pressure (80psi) is plenty enough to handle the weight of my front axle, however its not enough to keep the wandering down. I currently run 90 as i'm still testing different pressures.


- Cheap Handling Fix front and rear. Made a HUGE difference, but still allowed for quite a bit of "push" from passing semis and wind.


- Reload the coach to move as much weight to the front as possible.





$$$ - All of these were done simultaneously by a truck shop

- Trac-Bar: The track bar works so well, I can feel the coach lean away from the passing trucks vs the read end move to the right. Highly recommend one of these.



- Safe-T-Plus Steering Stabilizer: The steering stabilizer helps bring the steering wheel back to center and seems to help with the wandering some. I do love this, but it sounds like you have one already.



- Alignment: Oddly enough the alignment was actually very good. I recommend having the toe set to 1/16" in on each side for a total toe of 1/8" in. Set as much positive caster as possible and still be in spec with Ford recommendations. Mine were already right at or very close to the upper limit.


At this point, i'm still playing with tire pressures to find my sweet spot, but right now the coach drives like a dream compared to what it did beforehand. I have the little brother to the Precept (equivilent to Jayco Allante 31V) so i'm on the 18K F53 with the 19.5" wheels. The smaller wheels make these issues that much more pronounced, as does the longer rear overhang.



Hope this helps..

[beachvic]

Foretm - So you run different pressures front to back? and lower in the front? and that helped? Ok I am willing to give anything a try. I also have 19.5 tires with a long overhang at the back. This was one reason I wanted the larger tires, but I bought used and had no choice! The track bar you added was that at the front or the back or both? Right now I am, a little gun shy buying anything since I just bought a safe-t-steer I didn't need. Any pictures of track bar located on a motorhome would help! Who knows I may already have that too...……..

[beachvic]

Just watched some You-Tube on track bar installation sounds like the thing I need to do. Hawkstr let me know how the installation goes and the results. Foretm, I appreciate your input.

[Foretm]

Originally Posted by beachvic

Foretm - So you run different pressures front to back? and lower in the front? and that helped? Ok I am willing to give anything a try. I also have 19.5 tires with a long overhang at the back. This was one reason I wanted the larger tires, but I bought used and had no choice! The track bar you added was that at the front or the back or both? Right now I am, a little gun shy buying anything since I just bought a safe-t-steer I didn't need. Any pictures of track bar located on a motorhome would help! Who knows I may already have that too...……..

Negative.... I currently run 90 all around, but there would be nothing wrong with different pressures for different axles. Just make sure all tires on that axle are the same. AKA 90 in the front and 85 in the rear is ok.


Tracbar was rear, made a huge difference. I'll get you a pic when I get to the RV in a couple hours. I doubt you have the trackbar, you should have sway bars front and rear, and you may have a front tracbar, mine does. I added the rear tracbar.


I understand, sell the safe-t-steer or return it, and spend that money on the tracbar. The tracbar will attach the axle to the frame. See this video on the tracbar.


https://www.google.com/url?sa=t&rct=...ojd_t13c2EvCe8

[Foretm]

Originally Posted by beachvic

Just watched some You-Tube on track bar installation sounds like the thing I need to do. Hawkstr let me know how the installation goes and the results. Foretm, I appreciate your input.

gotcha... sorry didn't read all the posts before replying. yep the tracbar will help the side to side motion of the box over the axle. if you stiffen the rear sway bar by doing the CHF, that will help too.

[hawkster]

This is no glowing Trac bar endorsement since I only drove 15 miles with no toad in 15-20 mph wind. With my 2016 31ul my worst case scenario is interstate with wind, a lot of trucks, and pulling my toad. I did the test pre Trac bar where I got at the back of coach and pushed sideways and it was easy to rock back and forth. After Trac bar some movement but not much. DW says after Trac bar at low speeds making turns into other roads from a stop no extra oscillations back and forth from rear. Just one and done. On the drive the rear felt tighter, not all loosey goosey. You could feel wind gusts but a push not an 'oh $hit' moment. Further testing when I drive it some next month.

I had a local shop install it. They said one of the bolts/nuts on a Ford bracket was stripped. On my 18k frame one of the Trac bar brackets bolt to the sway bar axle mount. On larger chassis they use the differential cover. The sheet from Super Steer said one to two hours labor. The shop charged two hours.

[Foretm]

When I got mine done, I had to use a shop about 1.5 hours away, and they had to keep it more than a single day, so I used the TOAD to get back and forth. I felt a huge difference in it the minute I pulled out of the parking lot. Everything just felt tighter and when I got on the interstate, the trucks are now a non-issue. I was able to hold the wheel with one hand for the 100 mile trip on the interstate at 65 with trucks passing me almost constantly while pulling my toad. Granted my toad is a small car, but its still back there and pushes on the rear as well. I'm happy with my purchase and the coash is SOOOOO much better to drive now.

[NickM]

Seems redundant to install a track bar when I already have sway bars front and rear - chf adjusted to the second hole. Helped immensely with body roll but how does this help with steering?

I have an appointment with Fuller Ford in Cincinnati for June 12 to get front end aligned. My Precept is the large chassis (24k) so looking for suggestions again on alignment settings that owners like. 1/8" toe in sounds like it could help. I have alignment specs from several places and caster of 4.6 seems to be the magic number.

I've also considered the idea of adjusting the steering box but am apprehensive about that one.

I keep watching steering threads hoping to find the magic solution.

[Foretm]

Originally Posted by NickM

Seems redundant to install a track bar when I already have sway bars front and rear - chf adjusted to the second hole. Helped immensely with body roll but how does this help with steering?

Nick, sway bars and trac bars do two entirely different jobs, don't confuse them. Let's take them one at a time.


Sway bar: Also knows as anti-roll/anti-sway bars are used to limit body rolling by providing torsional resistance on the bar. This "U" shapeb bar is attached to the frame with hellwig struts, then to the axle in two places and finally on the other side of the frame with another hellwig strut. Looking at the rear of your coach, as the body begins to lean to the right, the sway bar on that side will push downward on the sway bar. This will in turn pull down on the left side of the body as the sway bar does not like to be twisted (resists torsionally). Conversely if you look at it from the suspension perspective, as the right side of the axle goes up, it will pull up on the left side of the axle in an attempt to keep the axle level.


Tracbar: Also known as a pan-hard bar is used to limit/prevent the side to side movement of the axle under the frame. Picture the rear of your coach again and this time the body is not rotating left and right, its shifting left and right while the axle stays in the same place. The trac bar attaches to the frame on one side and to the axle on the other. It allows for the suspension to articulate up and down, but does not allow side-to-side movement.


Lastly, if you look you likely have a front tracbar as well as the sway bar. They're not redundant, they're complimentary. If you look at the imaghe below, the black bar is the sway bar, the green is the tracbar.

[NickM]

Foretm

I don't recall seeing a trac bar when I did the CHF but I was pretty focused on getting the CHF done so I could have missed it, but I'm sure there is nothing green like that one under my front end.

I also have the Safety Steer Stabilizer which at first I felt improved the steering but after another 5k miles I can't say for sure.

If I look way way out in front I can minimize the see sawing effort I put in the steering wheel. If I let go of the wheel on reasonably good highway it will track in a straight line for a hundred yards.

My biggest complaint is when it decides to move towards the berm and I correct by adding left steering there is a delay before it responds. Same when it moves towards the center line, always a delay before the correction kicks in.
Initially I always overcorrected because of this delay and 6 hours of this became a very tiring day.

As far as big trucks, I can anticipate and be ready for the pressure wave. Even if I miss seeing him in the mirror I can usually recover easily enough to where I don't consider this a big problem.

Will a trac bar mitigate any of my issues?

[Foretm]

The picture was an example from a jeep, mainly to show the difference. I have the same issue with mine but honestly do not know what the fix is or if there is one. I think it could be indicitive of the F53 cchassis or it could be the particular one I have. I have a pretty good overhang past my rear axle and i think my front axle may be a bit lighter than it should be. This is where my experience and expertise falls off like a cliff. Beyond where I am now is uncharted waters for me, so i'm not sure what to do about this issue. I do know that I had major issues with the tail wagging the dog until the CHF and rear tracbar. If you don't have that problem then the tracbar may not be for you.

[NickM]

Foretm,

Well, disappointed to hear that to say the least, thought I had found a solution. Like you, I have exhausted my tiny bit of knowledge.

I still think (in my aging mind) that it has to do with slack in the steering gear box. Googling this issue has given me hours of reading pleasure (not) and I'm no closer to a solution than I was 2 years ago.

I have that long overhang in the rear which is a positive as the toad doesn't get blasted with road debris and I don't need a flap under the rear. Thinking about weighing again, wish I could find a good 4 wheel scale close to me.

We have a short trip coming up in June and I am close to pulling the trigger on adjusting the steering box before we leave. Maybe I can mark the original adjustment position so it can be returned to OEM adjustment.

Friends and family who are or were truck drivers says that cab over steering trucks have always drove like what I am experiencing.

All I know is that there sure is a lot of F53 vehicles on the interstate roads and am skeptical that they all exhibit the same problem.

[MikeThompson]

We have a 2018 Precept 35S. Now had it for 2 years and have 37,000 miles on it. When we first got it, I had a small problem with oversteering and getting blown around by trucks. I spent some time moving things around in my compartments, putting anything heavy ahead of the rear axle. I haven't done any mods at all and I can drive with one finger on the wheel with no problems. Never weighed it, just moved stuff around till it felt good. I would suggest trying that first. I've read a bunch of threads on here about all the mods that were done and I'm happy I didn't have to spend all that money.

[NickM]

Mike,

You are the first person I have encountered to make this statement. Do you know what your tire pressures are? Mine is at 100psi which makes for a stiff ride.

I haven't spent much so far, the SafeT Stabilizer has been my only expense and after seeing the blown tire videos that was pretty much a no brainer.

I've got my heavy stuff forward of the rear axle but I'll take another look around and see if I can make improvements. I only carry enough fresh water to flush the toilet when traveling, less than 1/3 tank.

Glad to hear someone has positive steering comments.