Issue link: http://read.dmtmag.com/i/34501
MOUNTING PROCEDURES FOR 16.00R20 AND 24R21 MICHELIN ® ™ ™ MOUNTING PROCEDURES FOR 16.00R20 AND 24R21 XL OR XZL TIRES Correct procedure for mounting multi-piece wheels for tubeless truck tires includes proper mounting and correct air pressure. Three-piece wheels consist of rim base, tapered bead seat, and locking ring. Mounting tools include: large bore valve, o-ring seal, brush or clean cloth with lubricant, small pallet of wooden blocks, air hose with a chuck or large bore valve, and miscellaneous tools. The first step in mounting is to properly position the wheel base by placing the wheel on the small pallet or blocks to raise it off the floor, facilitating the lock ring installation. Note that the wheel is placed on the support with the fixed flange side down. Using the large bore valve, lightly lubricate the rubber grommet on the valve base; insert and secure with the hex nut of both sides. Always use a large bore valve and not a standard truck valve since the larger diameter will permit better air flow and better bead seating. WHEEL LUBRICATION With a clean cloth or brush, lightly lubricate the rim base completely except for the two upper grooves. Lubrication in these grooves can cause the o-ring to be rolled out of the groove by the tapered bead seat when inflating the assembly. It is important to use a heavy lubricant such as MICHELIN Bib Grease or Murphy’s. Heavy lubricants do not dry as quickly, thus allowing more time to seat the beads during inflation. LUBRICATION OF THE BEAD Using a brush or clean cloth, lubricate the inside and outside of each tire bead area. This procedure plus the rim lubrication will allow the tapered bead seat ring to be installed more easily and allow the tire beads to seat properly during inflation. TIRE PLACEMENT ON THE WHEEL Place the tire on the wheel base. This can be done manually or by fork lift truck for easier handling. Exercise caution when sliding the forks below the sidewalls of the tires since an impact by the forks can damage the casing cords. Lifting the tire by the beads can damage or permanently distort the beads and should be avoided. TAPERED BEAD SEAT RING The bead seat ring should be lubricated on both sides before placing it on the wheel base. This allows it to slide between the tire and wheel base more easily and later over the wheel base during inflation. Lubricating the bead seating surface facilitates concentric seating of the beads during inflation. 130 Section Nine: Appendix ® O-RING SEAL The most important part of tubeless mounting on multi-piece wheels is the o-ring seal under the bead seat ring. It is imperative that the correct O-ring be used and properly installed. Check O-ring length and cross section diameter for correct fit. The MICHELIN O-ring seal reference number is 1506 for the 24R21, which is designated OR 6.6-21 for the 21-inch inside diameter. The 16.00R20 uses O-ring reference number 1681, designated OR 6.6-20 for the 20-inch or the corner ring, reference number 1443, designated A20-TYRAN. The corner ring has a slightly different mounting procedure – see wheel manufacturer for proper procedures. Some commercially available O-rings are too long. If too long, it will push out of the groove breaking the seal and the tire will loose air. Do not lubricate the O-ring prior to installation on the wheel. The lubricant tends to push the O-ring out of the groove breaking the seal. Make sure both the O-ring and the groove are free of debris. Place the O-ring in the bottom groove; it should fit tightly but not be excessively stretched. LUBRICATION OF THE O-RING The outer surface of the O-ring should be lightly, but well lubricated to allow the tapered bead seat to slide easily over the seal during inflation. Remember an incorrect O-ring or improper lubrication can force or push the O-ring out of the slot upon inflation causing air loss. Snap the lock ring in the upper rim groove. Check that the ring is fully seated in the groove. INFLATION Place the assembly in the horizontal (preferred) or vertical (if well lubricated) position for inflation in the restraining device and remove the valve core. This will allow the beads to slide more easily into position. Inflate to 80 psi for complete tire bead seating. Install the valve core and then adjust air pressure to that recommended for the load and condition. Remember the keys for good mounting are: 1. Correct size, type, and compatibility of components 2. Proper lubrication and mounting procedures 3. 80 psi initial inflation pressure for bead seating, followed by adjustment to recommended pressure. Adherence to these simple guidelines will ensure maximized performance and minimized downtime due to tire mismount. If you are having difficulty in mounting or cannot get the assembly to inflate or hold air, an incorrect component or incorrect inflation is probably the cause.