Support the pinion.
Keep the setting unresolved.
A separate toothless head/shaft, inner and outer bearing-race boundaries, spacer, depth-washer reference and dust/retention parts replace the former conflation of a long flange stem with the pinion region. An estimated internal carrier boss and web now contain matching reference pockets.
Inspect the pinion chain
Factory evidence and procedure boundaries
Factory PDF p. 147 separates the crown-wheel/pinion matched-set role, selected-depth washer, ATA7166 inner and BTB440 outer bearings, BTA532 spacer, 88G320 oil seal, 1G7439 dust cover, flange and retaining nut/spring washer. The adjacent carrier plate distinguishes cage, side bearings/caps and axle variants. These establish component roles, not fitted ratio, identity or dimensions.
The selected-washer list spans 2.95–3.30 mm. The displayed 3.125 mm washer is only the midpoint of that range: it is not an offered factory size, owner measurement or selected repair washer. No setting or part-ordering decision follows from its displayed thickness.
The earlier factory AKD1775 H.6 discussion distinguishes measured pinion depth and bearing preload and describes a shimmed-spacer arrangement. It is an earlier comparison, not a 1500/BTA532 collapsible-spacer procedure. Its adjustment values, torque and sequence are not transferred to this car. The complete applicable fitted procedure remains unresolved.
Declared geometry changes
| Interface | Construction and limit |
|---|---|
| Flange / shaft | The former240 mm hollow flange neck shortens to25.6333 mm, beginning at the retained Z250 seal plane and ending at the retained flange. A separate R12 toothless shaft/head reference occupies the bearing region. This is an architectural correction, not fitted shaft diameter, spline or actual pinion dimensions. |
| Carrier / bearings | An estimated R45 boss and annular support web receive inner and outer race pockets. The displayed inner bearing occupies Z150–172 and outer Z230–250 in the axle-local frame. All stations, diameters, tapers and seat details are estimates. Rollers, loaded contacts, lubricant paths and preload are absent. |
| Spacer / selected washer | The plain uncompressed spacer explains the between-bearing role. Its free/crushed length and seating are unknown. The unselected washer display remains separate from the factory selectable range; no shim selection or gear-depth calculation is simulated. |
| Nut / surrounding propshaft | A separate unthreaded nut and unloaded retaining washer sit at the source flange boundary. The rear propshaft flange/root receives an estimated R23 central recess for their envelope. This is not fitted pilot geometry, spanner clearance or a verified withdrawal path. |
| Preserved source boundaries | Only the carrier and pinion-flange meshes change in the axle source; six other meshes remain identical. Only the rear flange-yoke changes in the propshaft source; eighteen other meshes remain identical. Mating planes, bolt maps, nominal track, axle ends, wheel ends, side-gear sockets and halfshaft stations stay unchanged. |
Open relationships
No new owner dimensions are applied. Existing cabin/underbody photographs remain context rather than a calibrated hidden axle-internal survey. The cage, crown wheel and actual gear teeth/mesh remain unresolved; no gearset pairing, ratio, hypoid offset, bearing identity or selected setting is asserted.
The limited neighbor sample compares the new pinion parts with the retained axle and propshaft sources. It reports 0 positive contacts; that limited source result does not establish fitted, loaded or moving clearance. Bearing races, spacer and washer clear the reference carrier pockets; the retainer clears the new propshaft recess as construction only.
Offsets expose the shaft, races, spacer and retention boundaries. They do not unload bearings, crush a spacer, disengage splines, measure tooth contact or supply a verified overhaul/replacement procedure. Support points, flange loosening/torque, bearing preload and the applicable fitting sequence remain unverified.
Native exports and checks
Eight source groups contain ten valid STEP solids. Checks cover shaft/gear-head connectivity, open race/washer/spacer bores, race separation, carrier-pocket and retaining-recess nonintersection and exact preservation of the other source meshes. Viewer checks cover metric placement/picking, bearing passages/material witnesses, source ownership and declared inspection movement. They do not validate drivetrain operation or a fitted bearing setting.