Emery,
There are some E's included now. Will post a bit more updated info later in
the afternoon.
Roger
There are some E's included now. Will post a bit more updated info later in
the afternoon.
Roger
Load Range D recall
- Thread starter roger black
- Start date
Emery, tell me more about a recall on General load range "D" tires, plse. I must
have been asleep at the switch, for I missed it. TIA
> All of the figures are on D rated tires. No problems with E's so far.
>
> >
>
> > Roger
>
> >
>
> Roger - I'm not at all surprised by this. Now maybe some of the doubters
> will realize why GM and General Tire put out a DOT mandated RECALL on Load
> Range D tires. I've stated in the past that I was puzzled by the fact that
> if there was a RECALL on the brakes or on the steering everyone would
> immediately get it fixed. Why not the same attention to the tires? Perhaps
> the price savings between range D and range E clouds the mind. I'd rather be
> a little poorer and a little more alive.
>
> Emery Stora
> 77 Kingsley
> Santa Fe, NM
have been asleep at the switch, for I missed it. TIA
> All of the figures are on D rated tires. No problems with E's so far.
>
> >
>
> > Roger
>
> >
>
> Roger - I'm not at all surprised by this. Now maybe some of the doubters
> will realize why GM and General Tire put out a DOT mandated RECALL on Load
> Range D tires. I've stated in the past that I was puzzled by the fact that
> if there was a RECALL on the brakes or on the steering everyone would
> immediately get it fixed. Why not the same attention to the tires? Perhaps
> the price savings between range D and range E clouds the mind. I'd rather be
> a little poorer and a little more alive.
>
> Emery Stora
> 77 Kingsley
> Santa Fe, NM
This is archived at:
http://www.web-access.net/~bmassey/gmc-faq.html
Tire Load Range
A feud is brewing among GMC Motorhome owners on an Internet Newsgroup over
the correct tires for the motorhome. All load Range D radial tires were
recalled soon after their introduction, and they were replaced with Load
Range E tires. Surprisingly; many owners are still using Load Range D tires
and refuse to change, because they art' not convinced there is a necessity
to do so.
Why does the GMC Motorhome need Load Range E tin's? Is there
engineering analysis to support this change?
Last fall my 1976 Palm Beach had two separate tire-failure incidents
with Michelin 8.75R 16.5 Load Range D XCA tires within a period of four
hours. I bought the motorhome in Mar:h 1998, and had not changed the tires.
They had lots of tread and no sidewall checks. The first one had a tread
separation in the center of the tread for about 14 inches, and the second
blew almost entirely off the rim, completely severing the steel belts. The
last digit in most (!f the DOT codes was either one or zero.
I sent an e-mail message to Michelin describing the problem, and asked
if the tires were prone to this kind of problem. I got a call from the
company, and Michelin offered to replace the two bad tires outright at no
charge and the other five at ha[f price. The Michelin representative told
me to get the best price anywhere in the area, and that price would be the
basis for the adjustment.
I explained that I was going to change tires anyway that winter, but
Michelin was insistent on replacing all of the tires with new load Range E
tires. Since I was planning on changing my original 16.5-inch steel wheels
to 16 inch Alcoa aluminum wheels, I chose Michelin LT225/75R 16 Load Range
E XPS tires. The Michelin representative explained that Load Range D tires
were not suitable for the GMC Motorhome. The old tires were shipped back to
Michelin for inspection and testing.
Boy, was 1 impressed with the service!
Tom Warner
Vernon Center, New York
Michelin discontinued its XCA tires in 1988 when the company introduced its
XPS tires,Tom. The DOT codes indicate most of your XCA tires were
manufactured in 1980 and 1981, making them almost 18 years old when they
were replaced. Michelin is constantly doing aging studies, and I suspect
that is why the company wanted the XCA tires back. Old tires are hard to find.
General Tire didn't supply its polyester casing, Load Range D radial
tires as original equipment on the GMC Motorhome until the middle of the
1976 model year. Either your motorhome was not originally equipped with
radial tires, or a previous owner replaced the original tires prior to the
recall.
Not only were your tires much too old for a motorhome application,
they were the wrong Load Range for a GMC Motorhome. Michelin wants its Load
Range D and its polyester-casing (LTX) tires off GMC Motorhomes for the
same reason General Tire wanted them off GMC Motorhomes in the early 1980s.
They won't withstand GMC Motorhome punishment.
Michelin is familiar with the work my engineering firm did for General
Tire in the early 1980s that led to the General Tire recall. General Tire
replaced all of its original equipment, polyester casing, Load Range D
radial tires with Michelin all-steel, Load Range E radial tires, because
Michelin was the only manufacturer of all-steel radial tires at the time.
All steel construction was found to be the only tire construction that
would withstand the unusual lateral forces the GMC Motorhome exerts on its
tires. The motorhome's front-wheel-drive tires are subjected to unusual
lateral forces when the motorhome is driven around corners, and one tandem
rear tire skids left and one skids right when the motorhome goes around the
same corners. We found that an all-steel tire was the only tire strong
enough to put up with this abuse.
The reason for Load Range E is inflation pressure. Inflation pressure
determines the load carrying capability of a tire. The reason for the
confusion is static weight. The reason for seemingly overtiring is dynamic
weight.
The GMC Motorhome has an independent (front-torsion bar, rear-air)
suspension that its owners enjoy and appreciate. However, this suspension
throws weight around when the vehicle goes down the road dynamically.
Individual wheel loads can exceed 2,500 pounds, and can go as high as 2,900
pounds under extreme situations. We demonstrated this phenomenon
in Denver, Colorado, at the Summer FMCA Convention in 1981. I later wrote
about it in the two part series "How To Damage A Tire And Call It
Defective" that was published in the June and July 1983 issues of MOTORHOME
and TRAILER LIFE magazines. (Call 805-667-4366 for TRAILER LIFE reprint
information.)
Keep in mind that Load Range E tires have to be kept inflated to Load
Range E inflation pressures, otherwise their 2,680 pounds of load-carrying
capacity is lost. Load Range E tires have a minimum inflation pressure
requirement of 75 or 80 psi cold depending on the manufacturer. That seems
high and harsh to many GMC Motorhome owners, particularly considering that
Load Range D tires are only inflated to 65 psi cold, but they will only
carry 2,350 pounds.
Before General Motors would allow General Tire to recall the tires, we
had to demonstrate the technical need, and the replacement tires had to
meet GM Tire Performance Criteria (TPC). Since handling and ride quality
are two of the primary TPC considerations, we had to run a blind test on 65
versus 80 psi cold inflation pressure. Surprisingly, there was no
difference, and the recall went forward.
If you told someone they were driving with 80 psi versus 65 psi tires,
they would always report a harder or harsher ride. If you told them the
opposite, when the tires were inflated the same, they would report a softer
ride. If you told them nothing about inflation pressure, they could not
tell the difference.
One of the problems with Internet Newsgroups is you can't tell the
experts from the amateurs. Also, know-it-all amateurs seem to be more
vocal, and are all-too-frequent contributors.
(GMC Motorhome News June 1999)
>Emery, tell me more about a recall on General load range "D" tires, plse.
>I must
>have been asleep at the switch, for I missed it. TIA
>
>
> > All of the figures are on D rated tires. No problems with E's so far.
> >
> > >
> >
> > > Roger
> >
> > >
> >
> > Roger - I'm not at all surprised by this. Now maybe some of the doubters
> > will realize why GM and General Tire put out a DOT mandated RECALL on Load
> > Range D tires. I've stated in the past that I was puzzled by the fact that
> > if there was a RECALL on the brakes or on the steering everyone would
> > immediately get it fixed. Why not the same attention to the
> tires? Perhaps
> > the price savings between range D and range E clouds the mind. I'd
> rather be
> > a little poorer and a little more alive.
> >
> > Emery Stora
> > 77 Kingsley
> > Santa Fe, NM
http://www.web-access.net/~bmassey/gmc-faq.html
Tire Load Range
A feud is brewing among GMC Motorhome owners on an Internet Newsgroup over
the correct tires for the motorhome. All load Range D radial tires were
recalled soon after their introduction, and they were replaced with Load
Range E tires. Surprisingly; many owners are still using Load Range D tires
and refuse to change, because they art' not convinced there is a necessity
to do so.
Why does the GMC Motorhome need Load Range E tin's? Is there
engineering analysis to support this change?
Last fall my 1976 Palm Beach had two separate tire-failure incidents
with Michelin 8.75R 16.5 Load Range D XCA tires within a period of four
hours. I bought the motorhome in Mar:h 1998, and had not changed the tires.
They had lots of tread and no sidewall checks. The first one had a tread
separation in the center of the tread for about 14 inches, and the second
blew almost entirely off the rim, completely severing the steel belts. The
last digit in most (!f the DOT codes was either one or zero.
I sent an e-mail message to Michelin describing the problem, and asked
if the tires were prone to this kind of problem. I got a call from the
company, and Michelin offered to replace the two bad tires outright at no
charge and the other five at ha[f price. The Michelin representative told
me to get the best price anywhere in the area, and that price would be the
basis for the adjustment.
I explained that I was going to change tires anyway that winter, but
Michelin was insistent on replacing all of the tires with new load Range E
tires. Since I was planning on changing my original 16.5-inch steel wheels
to 16 inch Alcoa aluminum wheels, I chose Michelin LT225/75R 16 Load Range
E XPS tires. The Michelin representative explained that Load Range D tires
were not suitable for the GMC Motorhome. The old tires were shipped back to
Michelin for inspection and testing.
Boy, was 1 impressed with the service!
Tom Warner
Vernon Center, New York
Michelin discontinued its XCA tires in 1988 when the company introduced its
XPS tires,Tom. The DOT codes indicate most of your XCA tires were
manufactured in 1980 and 1981, making them almost 18 years old when they
were replaced. Michelin is constantly doing aging studies, and I suspect
that is why the company wanted the XCA tires back. Old tires are hard to find.
General Tire didn't supply its polyester casing, Load Range D radial
tires as original equipment on the GMC Motorhome until the middle of the
1976 model year. Either your motorhome was not originally equipped with
radial tires, or a previous owner replaced the original tires prior to the
recall.
Not only were your tires much too old for a motorhome application,
they were the wrong Load Range for a GMC Motorhome. Michelin wants its Load
Range D and its polyester-casing (LTX) tires off GMC Motorhomes for the
same reason General Tire wanted them off GMC Motorhomes in the early 1980s.
They won't withstand GMC Motorhome punishment.
Michelin is familiar with the work my engineering firm did for General
Tire in the early 1980s that led to the General Tire recall. General Tire
replaced all of its original equipment, polyester casing, Load Range D
radial tires with Michelin all-steel, Load Range E radial tires, because
Michelin was the only manufacturer of all-steel radial tires at the time.
All steel construction was found to be the only tire construction that
would withstand the unusual lateral forces the GMC Motorhome exerts on its
tires. The motorhome's front-wheel-drive tires are subjected to unusual
lateral forces when the motorhome is driven around corners, and one tandem
rear tire skids left and one skids right when the motorhome goes around the
same corners. We found that an all-steel tire was the only tire strong
enough to put up with this abuse.
The reason for Load Range E is inflation pressure. Inflation pressure
determines the load carrying capability of a tire. The reason for the
confusion is static weight. The reason for seemingly overtiring is dynamic
weight.
The GMC Motorhome has an independent (front-torsion bar, rear-air)
suspension that its owners enjoy and appreciate. However, this suspension
throws weight around when the vehicle goes down the road dynamically.
Individual wheel loads can exceed 2,500 pounds, and can go as high as 2,900
pounds under extreme situations. We demonstrated this phenomenon
in Denver, Colorado, at the Summer FMCA Convention in 1981. I later wrote
about it in the two part series "How To Damage A Tire And Call It
Defective" that was published in the June and July 1983 issues of MOTORHOME
and TRAILER LIFE magazines. (Call 805-667-4366 for TRAILER LIFE reprint
information.)
Keep in mind that Load Range E tires have to be kept inflated to Load
Range E inflation pressures, otherwise their 2,680 pounds of load-carrying
capacity is lost. Load Range E tires have a minimum inflation pressure
requirement of 75 or 80 psi cold depending on the manufacturer. That seems
high and harsh to many GMC Motorhome owners, particularly considering that
Load Range D tires are only inflated to 65 psi cold, but they will only
carry 2,350 pounds.
Before General Motors would allow General Tire to recall the tires, we
had to demonstrate the technical need, and the replacement tires had to
meet GM Tire Performance Criteria (TPC). Since handling and ride quality
are two of the primary TPC considerations, we had to run a blind test on 65
versus 80 psi cold inflation pressure. Surprisingly, there was no
difference, and the recall went forward.
If you told someone they were driving with 80 psi versus 65 psi tires,
they would always report a harder or harsher ride. If you told them the
opposite, when the tires were inflated the same, they would report a softer
ride. If you told them nothing about inflation pressure, they could not
tell the difference.
One of the problems with Internet Newsgroups is you can't tell the
experts from the amateurs. Also, know-it-all amateurs seem to be more
vocal, and are all-too-frequent contributors.
(GMC Motorhome News June 1999)
>Emery, tell me more about a recall on General load range "D" tires, plse.
>I must
>have been asleep at the switch, for I missed it. TIA
>
>
> > All of the figures are on D rated tires. No problems with E's so far.
> >
> > >
> >
> > > Roger
> >
> > >
> >
> > Roger - I'm not at all surprised by this. Now maybe some of the doubters
> > will realize why GM and General Tire put out a DOT mandated RECALL on Load
> > Range D tires. I've stated in the past that I was puzzled by the fact that
> > if there was a RECALL on the brakes or on the steering everyone would
> > immediately get it fixed. Why not the same attention to the
> tires? Perhaps
> > the price savings between range D and range E clouds the mind. I'd
> rather be
> > a little poorer and a little more alive.
> >
> > Emery Stora
> > 77 Kingsley
> > Santa Fe, NM
