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Topic: Tire clearance issue (Read 2086 times) previous topic - next topic

Re: Tire clearance issue

Reply #25 –
Quote from: flite2010 –
With the automatic level system our coach lowers to the point where the tires are occasionally resting against the bottom of the coach.  This has left depressions in the skin at every tire location.  There is a spacer installed to limit the amount the coach can lower. Has anyone increased the height of the spacer to prevent the tire to coach contact?

Fixing to put 8 - 1/2" bar stock pieces in mine, got them cut just got to get down to the shop to weld them in. Right wrong or otherwise it will allow me to move the coach with the air bags deflated if the need where to arise. These will be welded to the original suspension stops
Bruce, Linda, and Macy
Zoey RIP 1/20/19
1999 U295 40' build #5400
2017 silver Jeep Wrangler, 1260 watts of solar on top
Moving around the country

Re: Tire clearance issue

Reply #26 –
We have a '96 U-295 and it had the "scuff marks" since we got it in 2005. It now has 150,000 miles on it and I'm just not worried. We have no problem with the floor. We did get into a minor problem with tire sizes a couple of years ago and the company we bought them from admitted they'd told us the wrong information about the sizes after we'd gone about 100 miles. Tehy made good on the deal by installing another brand with the correct size. Our worry was the tires in front rubbing on the airbag fram. That can't be good on either the frame nor the tire. Happy now with original size tires and some rub or scuff marks on nderside of coach. I trust James to give me the correct information when I need it and for you guys to hash out all the possibilities so I can make an informed decision. Maybe if you all just sent me your money and I'd be the test rig for all the possible changes offered on the Forum...yes, that's an idea!
Larry
1996 U295 36'
Build # 4805
Actually we sold it but just like to lurk

Re: Tire clearance issue

Reply #27 –
Quote
From all that I can gather, many (if not all) 1996 to 2000 model year FT coach tires contact and deform the undersides of the floors when all air is dumped from the airbags.
My 95 has the same scuff issue.
jor
93 225
95 300
97 270
99 320

Re: Tire clearance issue

Reply #28 –
Quote from: bbeane –
Fixing to put 8 1/2" bar stock pieces in mine, got them cut just got to get down to the shop to weld them in. Right wrong or otherwize it will allow me to move the coach with the air bags deflated if the need where to arise
Bruce,
Thank God you are welding them in and not glueing them on as someone suggested. With glue they will eventually pop free and be kicked up by a tire into somebody behind.
1/2" over the existing 3/8" round piece is the number that I came up with (1995 U300) to insure no tire contact with Mich 275/80R x 22.5. I went a different route and came 7/8" off of the frame and hose clamped on. Not totally sure what you have to disconnect to weld on your frame so just a reminder that maybe the tranny and engine ECM's should be disconnected before welding.
Rick

Re: Tire clearance issue

Reply #29 –
Quote from: Rick –
Not totally sure what you have to disconnect to weld on your frame so just a reminder that maybe the tranny and engine ECM's should be disconnected before welding.


Welding Checklist
The selected media item is not currently available.Barry BEAM #16014
2003 U320 40' AGDS
Beamalarm, Foretravel technical help and specifications
"Whatever the mind can conceive and believe, it can achieve"

Re: Tire clearance issue

Reply #30 –
My U295 with Michelin tires has a small dimpled area in the floor over each tire ,but no real scuffing . So for me I don't think it's a problem.In the travel mode for me there is 3 1/2"  from the frame to the stops. I haven't heard of anyone bottoming out on the road as they drive, but I don't think I wont to reduce that 3 1/2" by adding any type of spacer.Gam
joseph gambaro
1999 U295 36'

Re: Tire clearance issue

Reply #31 –
Quote from: gam –
...........................I haven't heard of anyone bottoming out on the road as they drive....................................
Gam,
It's fortunate that you don't have to drive I-495 around Boston.
The Commonwealth of Massachusetts is famous for grinding 3 or more inches of pavement off miles and miles of highway, laying in short, ramped, approach aprons to say  4" or 5" higher concrete bridge sections and then turning 65 MPH/70 MPH traffic loose on it for several months at a time before they repave the highway.  I always try to ease up in time but you never know just how bad it's going to be except through recent experience.  Sometimes, even after they are done repaving, it's several inches of elvation change over a few short feet of highway (Glass smooth highway/several inches higher bridge section/glass smooth highway again, all at 65 MPH or you get trampled).....you get the picture. 
Anyway, the only times we have "bottomed out" (it's VERY evident when you do and you are not likely to ever forget it) have been when the cargo bays were empty, tanks were very low to empty and a new Commonwealth "wake up call" appeared.  This isn't a likely scenario for most owners, but we used to use the coach in a business where we were often returning to home base very lightly loaded.  We have had other FT friends describe similar "bottoming" experiences, not so lightly loaded, in the NE and in the Maritime Provinces.
Just for clarification,
Neal
The selected media item is not currently available.
Neal (& Brenda) Pillsbury
'02 U320 SPEC, 4200, DGFE, Build #5984
'04 Gold Wing
'07 Featherlite 24'
'14 Jeep Grand Cherokee Summit
MC #14494
Exeter, NH & LaBelle FL
Quality makes the Heart Soar long after Price is Forgotten

Re: Tire clearance issue

Reply #32 –
So from the sound of it you either hit the floor or add spacers and hit harder on the frame when you hit a bump. This is the first I've heard of hitting the floor and or bottoming out the suspension as your driving. I have been on some less then good roads { Metro Detroit } so my wife was always on pothole detail. But I can't think of a time when we bottomed out the suspension.I had been thinking more about clearance when parked ,and that adding spacers would lession suspension travel and in your case  a harder bump if you bottomed out..How thick is the flooring over the top of the wheels and is there any frame members in that area?Gam
joseph gambaro
1999 U295 36'

Re: Tire clearance issue

Reply #33 –
I would caution about increasing the height of the metal donuts because metal to metal contact can be very damaging to the suspension parts. I noticed that those donuts had made indents in the mating framing metal on my coach. I installed half inch thick high impact plastic between the top of the airbags and the frame. The bolts in the top of the airbag are long enough to accomodate this without modification. Now the weight of my coach is resting on the rubber bumper inside each airbag when the air is dumped and the tire does not touch the floor.

I would like to increase the ride height by one half inch, but am concerned about drive line and steering angles. Does anyone know if increasing ride height by a half inch will cause problems?

There are some threads from years ago describing how some folks inserted 3 inch thick blocks of metal between the axles and the framing to increase the distance between the tire and the floor. This allowed them to the leave everything else as it was. This also raised the center of gravity, such that I believe these coaches do not handle as well as they did before raising them. Has anyone ever driven one of these raised coaches?

Wyatt
96 U320 40 WTFE, build 4943
84 Toyota Supra towd
2015 Jeep Wrangler towd
Victoria, BC, Canada

Re: Tire clearance issue

Reply #34 –
Wyatt,

I am considering doing the same thing. The internal bumper is designed to prevent significant damage to the vehicle or suspension in the event of a sudden loss of air pressure in the spring. As they are currently installed they serve no purpose.  BTW how did you determine the the plate thickness?

 
The selected media item is not currently available.Bob & Faith Rozek
1997 U320 40'
Xtreme Remodel
2010 Scion XD

Re: Tire clearance issue

Reply #35 –
A change in travel mode setting from 8" to 8 1/2" is a good question for Foretravel. That would increase your driving clearance without a change in parked leveling clearance. More height and more air in the bags. Less chance of bottoming out. Koni shocks may help on the rebound.Gam
joseph gambaro
1999 U295 36'

Re: Tire clearance issue

Reply #36 –
Quote from: gam –
...........................How thick is the flooring over the top of the wheels and is there any frame members in that area?..........................
Gam
Gam,
Check yours with a magnet, but no frame members directly above my wheels (strictly intentional, I would guess).
3/32" (? guess ?) Fiberglass sheet, 1 and 1/2" rigid blue insulation foam, 1/2" plywood flooring, carpet/flooring.
See Dick's pictures in the following thread:

Replacing Generator fuel line on '99 U320

Neal
The selected media item is not currently available.
Neal (& Brenda) Pillsbury
'02 U320 SPEC, 4200, DGFE, Build #5984
'04 Gold Wing
'07 Featherlite 24'
'14 Jeep Grand Cherokee Summit
MC #14494
Exeter, NH & LaBelle FL
Quality makes the Heart Soar long after Price is Forgotten

Re: Tire clearance issue

Reply #37 –
As you raise the height, the driveshaft angle changes too.

Re: Tire clearance issue

Reply #38 –
Air spring Spec's:

Design Height: 7.5-8 inches
The selected media item is not currently available.Bob & Faith Rozek
1997 U320 40'
Xtreme Remodel
2010 Scion XD

Re: Tire clearance issue

Reply #39 –
I determined the effect a half inch thick spacer above the airbag would have by careful measurements facilitated by clamping rulers to frame members and adding some air. At 3/8 inch increase I could not slide a piece of thin metal between the tire and the floor, however, at half inch I could. Also, half inch thick material is readily available. I would have gone a little thicker (5/8 inch) if the airbag bolts had been longer.

If I park on gravel, I check for rocks stuck in the tire before dumping air.

A benefit to 295 75 tires over 275 80 is that lower air pressure is required to carry same weight.


 
Wyatt
96 U320 40 WTFE, build 4943
84 Toyota Supra towd
2015 Jeep Wrangler towd
Victoria, BC, Canada

Re: Tire clearance issue

Reply #40 –
Wyatt,

What is your airbag height in travel? They are designed to be set from 7.5"-8"
The selected media item is not currently available.Bob & Faith Rozek
1997 U320 40'
Xtreme Remodel
2010 Scion XD

Re: Tire clearance issue

Reply #41 –
While I did measure it some time ago, I donot remember the airbag height in travel mode. I am at the airport about to board a flight to Canada, but will return to my motorhome in ten days and I will measure it then.

I looked at the drive shaft when the coach was sitting in travel mode. The tranny shaft was slightly higher than the differential shaft.

 
Wyatt
96 U320 40 WTFE, build 4943
84 Toyota Supra towd
2015 Jeep Wrangler towd
Victoria, BC, Canada