2000 jeep 2.5 torque specs professional#
The content contained in this article is for informational purposes only and should not be used in lieu of seeking professional advice from a certified technician or mechanic. Learn more about Fel-Pro quality gaskets that are specifically designed for the repair environment, find your car part, or find where to buy your auto part today. Any bolts that pass through a water jacket must have a sealer applied to the threads to prevent corrosion and leaks. Too much oil will hydrolock the bolt and give false torque readings. Be careful not to over-oil the bolts, especially if they are threading into a blind hole. Clean, oiled threads prevent binding, allowing for accurate and consistent torquing. Using engine oil, lightly oil the threads and under the heads/washers on T-T-Y bolts unless otherwise specified by the vehicle service manual.Always clean the threads where the bolts pass through any thread damage, corrosion/rust, old sealer or thread locker compound will create excessive friction giving you a false base torque reading, robbing you of valuable clamping force.Be sure to verify the torque specifications and torquing sequence before you start. The head bolts should be loosened in steps rather than all at once. T-T-Y bolts should be removed in the reverse order of the sequence of which they are installed. Removing the bolts while the engine is hot can cause cylinder head warpage. Before removing T-T-Y head bolts, allow the engine to fully cool.Fel-Pro head bolt sets are application specific. It is very important to follow the proper torquing sequence and specifications when installing T-T-Y head bolts. Rotating the bolts a set amount of degrees and putting the fasteners in the yield zone will account for “clamp load scatter” or variations due to conditions such as assembly lubricant type, bolt and bolt hole thread condition, and surface finish of the fasteners. Getting to the precise yield zone (for maximum clamping force) is accomplished by tightening bolts to a certain torque spec, then turning the bolts a pre-determined number of degrees. The bolts are stretched into their elastic range, and in many cases, the stretching approaches the bolts' elastic limit, permanently stretching it. Once they reach this zone, they maintain a more precise and consistent level of clamping force across the entire head-to-block mating surface. Used by many manufacturers, especially on engines with aluminum heads and in conjunction with Multi-Layer Steel (MLS) head gaskets, T-T-Y (Torque-To-Yield) head bolts are engineered to stretch within a controlled yield zone. Remember, bolt stretch is how we get maximum clamping load. Unfortunately, using a larger diameter bolt is not the answer, as the larger a bolt it is, the less it will stretch. Today’s engines require higher clamping forces (due to increased combustion pressure) which cannot be achieved with conventional small diameter bolts normally found in these engines. This torque specification applies the proper clamp load to the joint while accounting for friction provided by the threads and the underside of the bolt head. Traditionally, a torque specification is a calculated number. This can be overcome by designing and offering better fasteners to address these conditions. However, conventional bolts can be an issue when they are used on aluminum heads, given that the expansion rate of this type of head can stretch typical bolts past their yield point. As long as the bolt is not stressed beyond its proof load (the maximum load a bolt can withstand and still behave in an elastic manner), it will return to its original length once the torque is relieved. Bolts are elastic by nature, meaning that within their elastic range, they'll stretch as the load on the bolt increases.