Record the family, mounting type, envelope and profile match before approving a mast-guide replacement.
Start with the bearing family
Combined bearings carry radial and axial load in one compact unit. Identify whether the part is a fixed-axial standard bearing (4.05x), a precision PR4 execution, an eccentric-adjustable 4.45x design, a jumbo high-load bearing, or a welded-plate AP assembly. The family controls interchangeability more than a similar outside diameter alone.
1. Capture every marking
- WINKEL-style numbers such as 4.056, PR4.056 or 4.456
- JD, MR, TR or 400-series cross-references
- Plate codes such as AP2, AP2-LUB, AP2-Q, AP6 or AP91-Q
- Any machine-maker or OEM drawing number
2. Measure the envelope
For preliminary identification record d, D, H, h, B, S and overall mounting length T when available. Note the axial-roller position and whether clearance is fixed or adjustable. Worn parts can understate diameters; treat measured values as a starting point.
3. Confirm the mating profile
Mast bearings run in steel U-profiles. Record the profile designation when known (Standard 0–5 NbV / JDG62–JDG123) or measure channel width, depth and wall thickness. A bearing that fits the stud may still be wrong for the channel geometry.
4. Describe adjustment and plate mounting
- Fixed axial roller or eccentric / screw adjustment
- Access direction for adjustment tools
- Standalone bearing versus welded plate assembly
- Plate thickness, hole pattern, weld location and coating
5. Add duty and commercial data
State truck or equipment capacity, mast stage, shock, grease access, quantity, destination and required documents. For export orders include the preferred Incoterm and packing notes.
Useful next pages
Technical note: This guide supports preliminary sourcing. Confirm the controlled drawing, tolerances, load capacity and application requirements before ordering or installation.