Suspension & Handling questions

[RVRandy]

OK, got the new rig and am now starting to work through the inevitable (unfortunately ) list of issues that need fixed.

I have few smaller issues like the drivers side mirror wont adjust; I have a bad wind whistle at the bottom center of the windshield at any speed above 45 mph; the bedroom slide out has a 1" gap at the bottom when closed but the top has virtually no gap; air leak at drivers rear when engine is shut off.

Turns out the air leak was just a loose fitting on the airbag on that side, fixed by tightening it up.

Heres my big issue: When I drive down the road, highway or city street, it pulls pretty strongly and constantly to the right. Enough that you have to keep constant pressure on the wheel to the left.

I've driven OTR trucks and this is not my first motor home, so I know about road crown and drift caused by crosswinds. This is not either of those. The air pressure is set and verified at 110 in both front tires.

Camping World had me take it to a heavy duty truck center to check the alignment. The tech told me the alignment looked fine and was within spec on camber and caster but the toe-in was excessive. It was set at 1/4" and should only be about 1/8" (according to him) so he adjusted it to that setting. The shop thought there was a chance that a tire was defective so they put the right tire/wheel on the left and visa versa. This way if the pull was caused by a bad tire, it should now pull to the left.

I left the shop with high hopes but within 60 seconds of getting on the highway I knew there was still a problem. There was still a pull to the right, maybe slightly less, but now the steering wheel would also shake/wobble whenever it was in the straight ahead/neutral position. Not good.

Got back to Camping World and they installed some tire balancing beads in both front tires. Test drove it and it made it a little smoother but did not impact the right pull or the steering wheel shake.

The CW shop manager and I were standing there scratching our heads trying to figure out what could be wrong when I noticed the coach was not sitting level, by quite a bit. The parking lot in this spot was very level and you could see the coach was leaning noticeably towards the driver side. We aired down the suspension fully and measured from the top of the rear wheel wells to the ground and it was exactly 35" on both sides. We then started the engine and aired up the suspension fully, we gave it a good 5 minutes to make sure it was all the way up. We re-measured at the wheel wells and the drivers side was 37" and the passenger side was 39", so 2 full inches higher than the drivers side.

I'm wondering if this lean is causing the pull to the right? It's enough to impact the steering geometry sort of like bump steer. Has anyone heard of this issue and what might be causing the lean? Any other ideas on the pull to the right?

Note the fuel tank was 95% full, the water tank was totally empty and we had nothing else loaded into the coach. So, I know it isn't heavily loaded on one side causing the lean. Both of the slides were fully retracted and closed too.

Does anyone know if there is an auto-leveling function in the air suspension? If so, maybe that is set wrong. Until I get under it and start rooting around I cant understand why an air suspension system would be sitting unlevel unless the airbags on the drivers side are receiving less air pressure.

[nccamper]

First thing I would do is work with the air pressures in front tires.
You said you had the air pressure at 110 PSI.
Two questions need to be answered:

1-What does the lable in the unit say for air pressure?
2-What is max air pressure on tire?

If the lable says less than the 110 PSI drop the pressure somewhere in the middle and go from there.
NCcamper

[RVRandy]

I called Freightliner tech support, explained the issue and gave them the front alignment numbers from the shop that re-set the toe-in.

They said chassis lean complaints are not uncommon. The chassis has an automatic air leveling suspension that is set to exact level when it leaves their plant. Then the coach builder builds the MH on top of it. In the case of the Palazzo it has the large slide on the drivers side with the fridge, stove, MW, etc so it is very heavy. If THOR doesn't re-adjust the air levelers when they're done, you have a bad lean.

They confirmed a bad lean to the left will impact steering geometry and contribute to a right pull in this case. They also confirmed the alignment specs seen are incorrect and should be re-checked after the air suspension is leveled.

THOR called me this morning and are going to arrange for the rig to go to Freightliner and get sorted out. I feel a LOT better now that were on the right track to get this corrected so it drives right.

I'll keep you posted with updates.

[tcopeland]

Did you get an answer on the slide issue? I have the same issue on the main slide, bottom and front is out further than the top and rear.

[RVRandy]

Originally Posted by tcopeland

Did you get an answer on the slide issue? I have the same issue on the main slide, bottom and front is out further than the top and rear.

Not yet, waiting on another call from THOR to cover that issue. I'll post up when I get an answer. From my reading, I do believe there is a way to adjust the slide out mechanism to correct this.

[tcopeland]

I was told by one person that the slide motor gear can be moved from one rail tooth to another to pull in or push out the slide depending on which way you need to go.
Did not get that from Thor although that makes since.

[TheArnolds]

Originally Posted by RVRandy

I called Freightliner tech support, explained the issue and gave them the front alignment numbers from the shop that re-set the toe-in.

They said chassis lean complaints are not uncommon. The chassis has an automatic air leveling suspension that is set to exact level when it leaves their plant. Then the coach builder builds the MH on top of it. In the case of the Palazzo it has the large slide on the drivers side with the fridge, stove, MW, etc so it is very heavy. If THOR doesn't re-adjust the air levelers when they're done, you have a bad lean.

They confirmed a bad lean to the left will impact steering geometry and contribute to a right pull in this case. They also confirmed the alignment specs seen are incorrect and should be re-checked after the air suspension is leveled.

THOR called me this morning and are going to arrange for the rig to go to Freightliner and get sorted out. I feel a LOT better now that were on the right track to get this corrected so it drives right.

I'll keep you posted with updates.

I do not have any handling issues but I am scheduled to have a one year service done at Freightliner (Gaffney, SC) in February (birthdate of my chassis). When I made the appointment they wanted to know if I wanted to have the chassis aligned which opened up a discussion. According to the nice lady on the phone she said that they have found some minor alignment issues after the body has been installed so I agreed to have them align and check the height adjusts on the airbags. Note: my rig appears to sit level left to right but it will not hurt to have them check everything.

[RVRandy]

Originally Posted by TheArnolds

I do not have any handling issues but I am scheduled to have a one year service done at Freightliner (Gaffney, SC) in February (birthdate of my chassis). When I made the appointment they wanted to know if I wanted to have the chassis aligned which opened up a discussion. According to the nice lady on the phone she said that they have found some minor alignment issues after the body has been installed so I agreed to have them align and check the height adjusts on the airbags. Note: my rig appears to sit level left to right but it will not hurt to have them check everything.

Thats a good idea assuming the cost is reasonable. Their tech support folks told me it is recommended to check the ride height at least annually. You do that by making sure the suspension is fully aired up, then you measure from the bottom of the frame rail to the center of the bolt that goes through the bottom of the shock absorber. The measurement for a Palazzo is 10.5". The measurement is the same for the front axle and the rear axle. The tolerance is plus or minus 1/4".

They also measure to make sure the rear axle is properly aligned with the front end. The springs can sag causing the rear axle to get out of alignment even though the air suspension is compensating to keep the ride height close. Making sure everything is aligned correctly gives you better handling, improved tire life and can even help your fuel mileage a little bit.

[Mr_D]

Originally Posted by nccamper

First thing I would do is work with the air pressures in front tires.
You said you had the air pressure at 110 PSI.
Two questions need to be answered:

1-What does the lable in the unit say for air pressure?
2-What is max air pressure on tire?

If the lable says less than the 110 PSI drop the pressure somewhere in the middle and go from there.
NCcamper

On most 22.5" RV tires the pressure on the sidewall in NOT the maximum pressure, it is the MINIMUM pressure required to support the maximum rating of the tire. The tire charts are the same way. Toyo is one that does put the maximum pressure on the sidewall, there may be others too.
The only accurate way to get the correct pressure is to weigh the rig on all "corners" and check the charts using the same pressure of the heaviest "corner" across all tires on that axle.

[Butte64]

Originally Posted by TheArnolds

I do not have any handling issues but I am scheduled to have a one year service done at Freightliner (Gaffney, SC) in February (birthdate of my chassis). When I made the appointment they wanted to know if I wanted to have the chassis aligned which opened up a discussion. According to the nice lady on the phone she said that they have found some minor alignment issues after the body has been installed so I agreed to have them align and check the height adjusts on the airbags. Note: my rig appears to sit level left to right but it will not hurt to have them check everything.

This is great information for when I do mine next year. Looks like I need to start a list of all the things to have checked so I don't forget. It would be great if you would share your list of what was checked and done after your February visit.

I am not able to schedule it yet but am looking forward to Camp Freightliner in the Spring.

[TheArnolds]

Originally Posted by Butte64

This is great information for when I do mine next year. Looks like I need to start a list of all the things to have checked so I don't forget. It would be great if you would share your list of what was checked and done after your February visit.

I am not able to schedule it yet but am looking forward to Camp Freightliner in the Spring.

Jerry,

What I can do after my service visit in February is to send you a PM with copies of everything they did so you have an idea of the service items and cost.

I hope that you and yours have a very Merry Christmas and a safe New Year!

Jack

[Butte64]

Originally Posted by TheArnolds

Jerry,

What I can do after my service visit in February is to send you a PM with copies of everything they did so you have an idea of the service items and cost.

I hope that you and yours have a very Merry Christmas and a safe New Year!

Jack

Wonderful. I hope the list is not too exten$ive.

Happy holidays. Meanwhile we are going to take the Palazzo to Cane Creek RV Resort on Lake Greenwood this weekend.

[RVRandy]

The steering issue is resolved! TransWest Freightliner in Commerce City, Colorado got the air suspension adjusted so it rides nice and level. Then they checked the front end alignment. Camber and caster were OK but it was actually toe'd out! That is bad and explains the pull and the wobbly steering wheel. This would have greatly shortened the life of the front tires too. It is now set to 1/16" toe in, no more pull to the right and the steering is pretty solid now. Like all MH's though it still has a little bump steer in the wheel when you hit good size bumps & ruts so I am going to go ahead and add a Roadmaster steering stabilizer too. That should make it solid as a rock.

[TheArnolds]

Originally Posted by RVRandy

The steering issue is resolved! TransWest Freightliner in Commerce City, Colorado got the air suspension adjusted so it rides nice and level. Then they checked the front end alignment. Camber and caster were OK but it was actually toe'd out! That is bad and explains the pull and the wobbly steering wheel. This would have greatly shortened the life of the front tires too. It is now set to 1/16" toe in, no more pull to the right and the steering is pretty solid now. Like all MH's though it still has a little bump steer in the wheel when you hit good size bumps & ruts so I am going to go ahead and add a Roadmaster steering stabilizer too. That should make it solid as a rock.

Thanks for the update on your handling issues! I would be interested in getting your opinion after installing the steering stabilizer?