ROLLER GP-TRACK CARRIER 4280056 - Caterpillar

Tooling and Equipment
Table 3
Required Tools
Part Number Part Description
4C-8648 Cleaner
5P-1720 Seal Pick
8S-2257 Eye Loupe As Cleaning
Bolts should be cleaned prior to inspection, except if bolts are bent, or damaged. Cleaning and inspecting ensures that no damage is hidden by grease or dirt. Use a wash tank or a coarse brush with a mild petroleum-based solvent. Cleaning the adhesive lock bolts will remove the coat of oil from the bolt, so these bolts should not be reused.Be sure that the solvent does not have any water contamination. Also, never use a chlorinated solvent. Surface pitting can be caused by either water or chlorine. Pits can cause areas of highly concentrated stress. These areas are called stress risers. Stress risers are more likely to result in failure of the bolt.A good solvent for a wash tank and hot tanks is 4C-8648 Cleaner. This cleaner is a strong alkaline cleaner, which will not damage aluminum parts. The cleaner is available in 19 L (5.0 US gal) and 208 L (55.0 US gal) containers.
Illustration 1 g03858781
Nomenclature
(1) Threads
(2) Shank
(3) Fillet
(4) Washer Face
(5) HeadInspection
Refer to Illustration 1 for the nomenclature of the bolt and areas that need thorough inspection. Illustration 2 indicates areas of highest stress, which should be examined especially closely.Corrosion is wear that can have two different causes. One is the result of chemical or electrochemical reaction on metal surfaces. Example is surface rust or pitting rust. The other cause is the result of movement between the surfaces of the bolts and mating parts. Movement between the surfaces causes microwelding among each of the surfaces. Microwelding can be caused by loosening bolts or abnormally high forces near the bolts contact points. Microwelding can also happen if the clearance of the bolt and the tapped holes do not line up. These conditions result in pitting, or fretting.The 8S-2257 Eye Loupe As is useful in close inspection of surface irregularities, which includes lines and pitting.
Illustration 2 g03858787
Three areas of highest stress on bolts
(6) First thread root and shank
(7) First thread root above nut or tapped hole
(8) FilletThreads
Check the full diameter of bolt threads for damage. Verify the bolt for nicks, cracks, corrosion, or stripped threads. Examine the bolt for any structural overstressing. Excessive stress may also cause rolling of the threads or stripping. Pay particular attention to areas (6) and (7) in Illustration 2. The first full thread at the shank, and the first thread above the nut or tapped hole. Do not reuse bolts with signs of yielding or other thread damage.Shank
The shank is to be checked for corrosion, deep pitting, cracks, or wear from surface contact. These factors are called stress risers, which decrease the effective strength of the bolt. Check the shank also for plastic deformation and scrap any bolts with this condition. Next, check for bending which may not be obvious. Check the bolt for bending, by rolling the bolt on a smooth table with the head just off the edge, and watching for wobble. Replace any bolts