Ten Most Frequently Asked
Technical Questions
Please click below to find answers to these technical questions about Neapco products.
If your question is not covered, click here to forward your question to our technical support staff.
Can the number on the cross forging identify a universal joint?
How do I identify a universal joint when I don’t
know what vehicle
it came out of?
Does Neapco offer universal joints that convert one size to another?
Why is the JL (Journal Length) no longer listed in the 2005
Universal
Joint catalog?
What is Alumiguard Coating and when is it necessary?
Do Brute Force Universal Joints require lubrication?
What type of grease should I use to lubricate my universal joints equipped with grease fittings?
How do I identify a repair ball kit for a double cardan CV head?
When does a driveshaft need to be balanced?
When replacing a slip yoke on a spline stub, does alignment matter?
Q: Can the number on the cross forging identify a universal joint?
A: No, this number only identifies the forging and/or lot for the manufacturer. Many different parts can be manufactured from the same forging.
Q: How do I identify a universal joint when I don’t know what vehicle it came out of?
A: It must be identified by size or dimension. First, measure the bearing cap diameter. Second, identify the type of lock-up (inside or outside clips). Third, measure the lock-up dimension. Then match it to the listings in the dimensional section of the 2005 Universal Joint catalog. The dimensional section is broken down by part type and sorted in two manners, first by size smallest to largest, then numerically by part number.
Q: Does Neapco offer universal joints that convert one size to another?
A: Yes, we offer 33 different conversion universal joints. They can be located and identified in the 2005 Universal Joint catalog under the Dimensional Identification Listing for Conversion U-Joints. We list the part numbers being converted as well as the series to assist in proper identification.
Q: Why is the JL (Journal Length) no longer listed in the 2005 Universal Joint catalog?
A: Because the JL varies by manufacturer. The lengths were consistent years ago but are now different due to manufacturing methods, the use of thrust washers, bearing cap back pad thickness, and simply design. The most accurate way to identify a universal joint is: 1.) Measure the bearing cap diameter, 2.) Identify the type of lock-up, and 3.) Measure the lock-up dimension.
Q: What is Alumiguard Coating and when is it necessary?
A: Neapco applicable products feature chemically coated bearing surfaces to create a barrier between two dissimilar metals (aluminum and steel). Galvanic corrosion will occur between aluminum and steel over time if they are in direct contact. Neapco recommends the use of Alumigard-equipped universal joints for all aluminum yoke applications.
Q: Do Brute Force Universal Joints require lubrication?
A: Brute Force Universal Joints are factory lubricated with synthetic EP (Extreme Pressure) lithium grease.
Q: What type of grease should I use to lubricate my universal joints equipped with grease fittings?
A: A good quality lithium complex soap based EP (Extreme Pressure) grease with a NGLI grade of 1 to 2 is recommended.
Q: How do I identify a repair ball kit for a double cardan CV head?
A: Neapco has added application information in the 2005 Universal Joint catalog. It can be found in the Double U-Joint Constant Velocity Repair Components Section. We list the CV Repair Kits, Centering Yoke assemblies, ‘H’ yoke, and Universal Joints by application for the various CV heads in this section.
Q: When does a driveshaft need to be balanced?
A: Generally all driveshafts operating over 1000 RPM require balancing. Typically vehicle prop shafts rotate above the 1000-RPM range and require balancing. PTO (Power Take-Off) shafts powering agricultural implements usually run at 540 or 1000 RPM and do not require balancing. There are however many other types of PTO driveshafts that do require balancing such as drive shafts powering hydraulic pumps. Again the general rule is anything over 1000 RPM needs to be balanced.
Q: When replacing a slip yoke on a spline stub, does alignment matter?
A: Yes. Proper phasing is required to eliminate vibration. Many slip yoke and stub shafts are marked at the factory with alignment marks to insure the correct tooth on the stub and slip are mated together. If you do not locate a mark prior to disassembly, it is best to create your own phasing mark with paint to insure proper alignment during assembly.