Looking For Ride Improvement Suggestions

[KJB]

Hi all! I'm new to this forum and appreciate the fact that it is here for us. I recently took delivery of a 2011 Coachmen Mirada 35DS (Ford chassis) and we just completed our 3,600 mile maiden voyage. All in all, I was happy with the unit. Two things I wish were better are the ride and I have an annoying squeak with every bump that seems to be where the front slide is directly behind the driver. I'm thinking the ride could improve if I lower the tire pressure some. That may help my squeak too. I am running 95 psi cold which is the recommended maximum. Any input for solutions to my problems will be appreciated.

[DriVer]

Quote:

Originally Posted by KJB I'm thinking the ride could improve if I lower the tire pressure some. That may help my squeak too. I am running 95 psi cold which is the recommended maximum. Any input for solutions to my problems will be appreciated.

KJB, I am not feeling so comfortable with attenuating a squeak by lowering air pressure in my tires. Now you may want to stuff your motorhome with a typical load, full fuel and LP and go and get an idea of what the axle weights are on a CAT Scale. If you have a squeak - you need to see if you can have that fixed - mechanically.

In regard to shock absorbers, the Koni FSD performs really well in most applications and has a large following here on iRV2.

[KJB]

DriVer, thank you for your response. The squeak isn't the big issue but I do seem to hear it every time my suspension takes a blow from the road. I did weigh the unit fully loaded as we headed out on our maiden voyage. Front axle = 6,520#, Rear axle = 12,440#, toad = 3,980#, gross = 22,940#. I have Goodyear 19.5 inch tires and the load inflation chart I found online doesn't show weights that heavy for 19.5 inch tires. I inflated my tires to the recommended max on the placard of 95 psi. The advertised weights for my RV are GVWR 22,000 and GCWR 26,000.

Regarding Koni FSD shocks, I would gladly replace the Bilsteins even though the RV is new if that would make a significant difference. Again, I appreciate your input.

[Kathy_MD]

KJB Stated:
Front axle = 6,520#, Rear axle = 12,440#, toad = 3,980#, gross = 22,940#. I have Goodyear 19.5 inch tires and the load inflation chart I found online doesn't show weights that heavy for 19.5 inch tires."


KJB:
I have the same chassis and similar weights per axle - I run 80psi all around. The chart is available here.

On The Wings of Goodyear | RV Tires - Tire Care: Proper Tire Inflation

NOTE: As you discovered, the chart will not show the weights of your axle. However, they indicate the weight per wheel(tire). So for the front, divide your axle weight by two - for the rear axle divide by 4 and find the appropriate pressure.

PS: Based on your axle weights and a little math, you should be running 80psi all around.


Katherine

[Clifftall]

[QUOTE=Kathy_MD;689079]KJB:


I have the same chassis and similar weights per axle - I run 80psi all around. The chart is available here.

I agree. My tires are at 80 per my chart for my Michilen 235/80 22.5

[billyb]

for the squeak, squirt some cleaner on the leaf springs and hangers and then wash them off with a hose and see if that fixes it. i thought i was helping lube them by spraying wd40 into them ,and then they started squeaking, so i washed it out, and it stopped. iwould lower the air in the front tires a couple of pounds at a time and see if the ride gets better. 95 sounds kind of high for those tires.

[KJB]

Thanks again for the info. Kathy, I did have that chart and it did confuse me. I was looking for the axle load and not the individual tire load. I'm anxious to see what it's like at 80psi.

[LVJ58]

The one suggestion Driver made and I wholeheartedly agree, is to install Koni FSD shock absorbers on your coach. Although a bit pricey, they're well worth the $$$ and you'll be pleasantly surprised with a significant ride improvement. We have them on our coach and they provide a very comfortable ride.

Also as Kathy_MD mentioned, after getting your coach weighed, you can most likely reduce your tire pressure to 80psi and yet maintain a good margin of safety.

Good luck and keep us posted on your progress with ride improvement

[KJB]

Quote:

Originally Posted by LVJ58 The one suggestion Driver made and I wholeheartedly agree, is to install Koni FSD shock absorbers on your coach. Although a bit pricey, they're well worth the $$$ and you'll be pleasantly surprised with a significant ride improvement. We have them on our coach and they provide a very comfortable ride. Also as Kathy_MD mentioned, after getting your coach weighed, you can most likely reduce your tire pressure to 80psi and yet maintain a good margin of safety. Good luck and keep us posted on your progress with ride improvement

Thanks Jim. I have researched Koni FSD shocks and I only see listings up to 2007. I have asked the company through "Contact Us" if there is an application for a 2010 chassis. Haven't heard back yet.

[Clifftall]

Quote:

Originally Posted by KJB Thanks Jim. I have researched Koni FSD shocks and I only see listings up to 2007. I have asked the company through "Contact Us" if there is an application for a 2010 chassis. Haven't heard back yet.

KJB

The Bilstein shocks you have are IMHO just fine . I put Bilsteins on my 01 f53 and they improved my ride. They are now standard on my 08 f53. The Koni's may be better,however at this time I think the amount of money will not make that much of a difference.

Change the pressure in your tires as we have suggested and I think you'll be happier. Your never going to smooth out the concrete highways completely.

[bellsharbor]

You are running too much pressure in your tires. I had a bad squeak and it turned out to be the couch in the slide behind the driver’s seat. It was a short metal rod going through a U shaped metal piece in the front/center or the couch. Wrapped it with duck tape and the squeak has gone away. Good Luck--John

[KJB]

Update. I lowered my tire pressure from 95 psi to 82 psi in the front and 85 psi in the rear. The ride has improved significantly.