Tires/Wheels - Winter Tire/Wheel and Snow Chains
911 (996)7/04 4440
Binder - Group 4, Running Gear
This bulletin replaces bulletin, Group 4, 6/03 and 7/03.
Date: 10-9-04
Winter Tires, Wheels, and Snow Chain Applications
Vehicle Type:
911 Carrera (996) and 911 Carrera 4 (996)
Model Year:
1999 (X) up to and including 2005 (5)
Concern:
Winter tires, wheels, snow chains and spacer rings - status as of 08/2004
Information:
Approved Winter Tires and Types
Mounting Instructions:
Instructions for proper tire mounting are located on the tire sidewall.
Arrow with Rotation marking = directional mounting
Inside/Outside marking = mounting on specified side only
Arrow with Rotation marking
and Inside/Outside marking = directional mounting on specified side only
If there are no mounting instructions on the tire sidewall, the tire must be mounted so that the DOT code is visible from the outside.
Danger!
Increased risk of accident due to insufficient tire pressure and/or due to defective tires.
> The tire pressure must never fall below the specified tire pressure.
> Check the tires at regular intervals for uniform profile wear and for possible damage such as cracks, bulges, detachments in the running surface, penetration by foreign objects, etc..
> Tires older than 6 years are to be replaced.
> Always replace valve stems.
Tire Pressures:
Valid for all tires with the M+S tread:
The above tire pressures are valid only for tires approved by Porsche. The tire pressures must be checked and adjusted cold (approx. 20° C/68° F). The values listed cannot be lower under any circumstance.
Spare Wheel Front and Rear Axle 4.2 bar (60 psi)
Collapsible wheel Front and Rear Axle 2.5 bar (36 psi)
Tire Sizes:
Approved Winter Tires and Wheel Sizes
Caution!
Risk of surface damage if the tires/valves are not mounted according to regulations, and/or if the wheel surface is not cleaned/cared for correctly.
> Carry out tire removal and mounting with a bead holding-down device only.
> Use a leather pad on the rim flange to support the valve insertion tool.
> Use only the Porsche centering clamping set for balancing.
> Do not clean the wheels with brushes (speak to car wash operator).
Deep scratches in the surface coating of the wheel cannot be repaired by polishing.
Wheels:
Overview of Porsche wheels for use with winter tires.
Reworking the Wing Seam:
The wing seam and if necessary the rear spoiler must be reworked in the areas shown (B).
Caution!
Paint damage can occur in the event of improper reworking of the wing seam.
> Only carry out reworking when the wing seam is partially warmed.
> Partial painting is required if the conditions are unfavorable.
The wing seam must be flanged over a width of at least 10 mm and at least 60°; never flange, grind or cut off more than 65°.
Adjusting the Rear Spoiler:
If the rear spoiler projects over the flanged rear side section (view A) the projecting part of the rear spoiler must be cut or ground off (arrow).
Spacer Ring/Wheel Installation:
The 5 mm thick spacer rings are mounted on the wheel hubs together with the brake discs using longer countersunk screws (M6x16), Part Number, 900 269 106 09.
Tightening torque: 10 Nm (7.5 ftlb.).
The 5 mm spacer ring must remain on the vehicle when fitting the spare wheel.
Wheel mounting must take place with the 5 mm longer wheel bolts of the 911 GT3, Part Number, 996 361 203 90. These GT3 wheel bolts are marked with GT or with a red color on the face surface (arrow) of the bolt head, or the rotating spherical cap ring is galvanized in red.
Dimension X = approx. 50 mm.
Tightening torque: 130 Nm (96 ftlb).
The 17 mm spacer rings are mounted on the wheel hubs using the standard wheel bolts, Part Number,
996 361 203 00/01 (dimension X = approx. 45 mm). Tightening torque: 130 Nm (96 ftlb.).
The wheels are mounted on the 17 mm spacer rings using wheel nuts. Part Number, 999 182 003
36. Tightening torque: 130 Nm (96 ftlb.).
The 17 mm spacer ring must be removed when fitting the spare wheel.
Snow Chains:
Porsche offers the following snow chains as accessories:
Observe the tire chain installation instructions.
For safety reasons, snow chain equipped vehicles may not be operated at speeds above 30 mph (50 kmh). Always observe local laws and ordinances.
General:
Always use new valves when changing tires:
Rubber valves, Part Numbers, 900 265 001 50 and 000 044 600 00. Only steel valve caps, Part Number, 993 361 163 90 may be used.
Always observe any possible instructions concerning the rolling direction and/or specifying which side the tires must be mounted on.
Coat the tire beads and humps with mounting lubricant before mounting the tire. This ensures that the tire beads will slide over the humps easily. In order to prevent the tire from turning on the wheel, avoid extreme driving maneuvers (acceleration and braking) during the first (100 to 200 miles) with new or recently mounted tires.
In order to optimize smoothness of rolling, it is appropriate - and necessary in individual cases to mount the tire in a certain (favorable) position with respect to the wheel (matching). Matching (uncontrolled and controlled) is explained below:
Uncontrolled matching:
Turning the tire on the wheel by 90° or 120° if necessary in order to achieve an acceptable value with regard to rolling smoothness (true running, imbalance and weight distribution of balance weights).
Controlled matching:
With a balancing machine with matching program. In most cases, this produces an even better result with regard to the rolling smoothness (true running, imbalance and weight distribution of the balance weights) than can be achieved with uncontrolled matching. Maximum permissible radial runout and lateral runout of the wheels < 0.7 mm. Maximum permissible radial runout and lateral runout of the wheels with tires < 1.25 mm. Values < 1.50 mm - ideally approx. 0.5 mm - are desirable.
The mounting pressure (seating pressure) of 58 psi/4.0 bar overpressure must not be exceeded before both tire beads are evenly seated on the rim flange.
If new tires are to be mounted or the tires of one axle are to be replaced, tires of the same make, the same type and with the same specification code must always be used on each of the two axles. If tires are replaced on one axle only, the different tread depth from that on the other axle can cause a noticeable change in the familiar handling. This is especially the case if new tires are mounted on the rear axle. This effect decreases with increasing tire mileage.
When replacing a tire on an axle, make sure that the tread depth of the new tire does not differ from that of the other tire by more than 30 %.
If a tire is damaged and it cannot be determined with absolute certainty that there is no ply damage - with all of its consequences - or if the tire was thermally or mechanically overloaded due to a loss of pressure or other prior damage, we recommend replacement of the tire in question for safety reasons.
Repairs on "ZR" tires are not allowed, as is the use of inner tubes in tubeless tires. Tires age due to chemical and physical processes, which can impair their function. Tires that are stored unused for an extended period harden and become brittle faster than tires that are in continual use. Hairline aging cracks can occur on older tires. On tires in continual use, the kneading action activates the plasticizer in the rubber and thereby prevents hardening and cracking.
Therefore, attention should be paid not only to the tread depth but also to the age of the tire. Tires should not be older than 6 years. The age of the tire can be determined via the DOT code on the sidewall, which indicates the production date of the tire: e.g. DOT 2201=22nd week of 2001.
Tires/complete wheels must be stored in a cool, dry and dark room with adequate ventilation. They must never come into contact with fuel, oil, grease or chemicals.
Complete wheels can be stacked for storage; it is advisable to increase the tire pressure by 0.4 bar. Optimum conditions for proper storage of the complete wheels are provided by the Original Porsche storage stand (trolley), Part Number 000 044 000 38.
If the tires are not mounted on wheels, it is best to store them in vertical position. Tires stored in vertical position should be turned every two weeks in order to prevent excessive flattening. If the tires are stacked in horizontal position, they will become severely deformed and cannot be seated in the rim flange easily when they are mounted.
Working Times:
Reference:
911 Carrera (996) Poses Technical Manual, Group 4
Repairs: 44 - Wheels and Tires. Page 44-1 to 44-33
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