1. Working Principle & Value (Location/Comfort/NVH)

Control arm bushings sit between the control arm and the subframe/body. As a rubber–metal composite, they deliver three core functions:

1. 1) Location & guidance – constrain control-arm DOF under steering, braking, and acceleration to maintain camber/caster geometry.

2. 2) Ride comfort – the rubber layer provides axial/radial compliance to filter fine road inputs and harshness.

3. 3) NVH – properly tuned dynamic stiffness and internal damping attenuate structure-borne noise; robust bonding and formulation prevent low-temperature squeal or knock after thermal aging.

2. Structure & Materials (Inner/Outer Sleeve + Rubber + Vulcanized Bond)

· Inner sleeve: precision-machined steel tube or cold-drawn tube; phosphate/zinc for corrosion protection; clamps with the bolt and carries torque.

· Rubber layer: NR/NBR/HNBR/PU per duty; compound & hardness govern dynamic stiffness, hysteresis, and media resistance.

· Outer sleeve: roll-formed steel; blasted + primered surface to ensure OD retention and concentricity during press-fit.

· Vulcanized bonding: one-shot rubber-to-metal chemical bond; primer/adhesive/topcoat tri-layer with peel strength meeting/exceeding ASTM D429; resistant to oil and hot water shock at the interface.

3. Material / Hardness / Temperature Comparison

Material	Typical Hardness (Shore A)	Continuous Temp	Oil/Fuel Resistance	NVH Behavior	Typical Use
NR (Natural Rubber)	55–70	−40 to +90 °C	★	Compliant, quiet	Mainstream comfort
NBR (Nitrile)	60–75	−30 to +110 °C	★★★	Slightly firmer	Light oil exposure / service
HNBR (Hydrogenated NBR)	60–80	−40 to +150 °C	★★★★	Stable	High temp / oily
PU (Polyurethane)	70–85	−40 to +120 °C	★★	High stiffness	Sport/heavy-duty/mods

Recommendation: for comfort-oriented daily use choose 60–65A NR/HNBR; for heavy load or rough roads choose 70–75A HNBR/PU. Optional thickened outer sleeve or stiffened rubber versions are available to balance poor suburban roads and highway operation common in Latin America.

4. Part Number & Fitment: Correct Spelling and Common Mistypes

Correct PN: KD35-34-470

Common mistypes/SEO variants: KD3534470 (no hyphens); KD35 34 470 (spaces); KD35-34470 (one hyphen missing); KD35-34-470A / KD35-34-470B (suffix letters on aftermarket/revisions—verify dimensions).

Fitment: Mazda CX-5 across multiple model years/positions (e.g., front lower control arm rear bush). Verify by VIN and on-vehicle measurement. Platform updates may change OD/width slightly.

5. Dimensions & Tolerance Quick Reference (mm/inch)

Variant	Outer Ø OD	Inner Ø ID	Overall Width W	Flange T	Tolerance (typ.)
A	60.0 mm (2.362 in)	14.2 mm (0.559 in)	50.0 mm (1.969 in)	3.0 mm (0.118 in)	OD/ID ±0.20 mm, W/T ±0.15 mm
B	62.0 mm (2.441 in)	14.2 mm (0.559 in)	50.0 mm (1.969 in)	3.0 mm (0.118 in)	Same as above
C	63.0 mm (2.480 in)	14.2 mm (0.559 in)	50.0 mm (1.969 in)	3.0 mm (0.118 in)	Same as above

If interference fit is too loose/tight: choose +0.05 / +0.10 mm OD micro-adjust versions, or share subframe bore data so we can match tolerance bands.

6. Selection Steps (Road/Load/Temperature/Oil → Hardness)

4. 1) Confirm position & OD variant: remove old part / measure subframe bore; check the table above.

5. 2) Road condition: Smooth urban → 60–65A; Rough/unpaved → 70–75A (PU optional).

6. 3) Load: frequent full load/towing → +5A hardness; consider thickened outer sleeve.

7. 4) Temperature: hot climate/under-hood heat → HNBR recommended.

8. 5) Oil exposure: seepage/fuel contact → NBR/HNBR.

9. 6) NVH target: noise-sensitive cabins → NR 60–62A, dynamic stiffness tolerance ≤ ±10%.

10. 7) Lead time & MOQ: stock/samples MOQ 50–100 sets; customization 20–30 days (excluding new tooling).

7. Installation Steps, Torque & Re-torque Interval

Tools: Hydraulic press & cups, torque wrench, marker, cleaner, oil-resistant assembly lube (metal interfaces only; never on rubber/bondline).

Procedure:

11. Lift vehicle, remove wheel; support the lower arm; mark original ride-height position.

12. Remove arm fasteners and ball joint; extract old bushing; clean bore.

13. Orientation: follow index notch/arrow on shell if present; avoid eccentric install.

14. Press new bushing to shoulder stop; ensure coaxiality and flush seating.

15. Reassemble arm & bolts; snug only. Lower vehicle to ride height before final torque to prevent rubber pre-twist.

16. Road-test and recheck.

Reference torque and interval:

· Control-arm front/rear bushing main bolt: 130 N·m (±10)

· Bushing bracket to subframe bolts: 95 N·m (±10)

· Re-torque interval: inspect/re-tighten after 800–1,200 km; reinspect after severe pothole impacts.

8. Common Mistakes & How to Avoid Them

· Final torque with wheels hanging → rubber pre-twist & early cracks → always torque at ride height.

· Lubricant on rubber → bondline slip/migration → lube metal interfaces only.

· Wrong orientation/eccentricity → NVH abnormality, pull → follow marks/arrows.

· Corroded bore untreated → loose press fit → repair bore and choose micro-oversize OD.

· Under/over-torque → clunking/stripping → use a calibrated torque wrench.

9. Troubleshooting (Symptom → Cause → Fix)

Symptom	Possible Cause	Solution
Thump on stop/go	Rubber debonding/hardening	Replace; choose higher bonding grade
Pulling / tire wear	Eccentric install / loose OD fit	Reinstall & align; select +0.05 mm OD
Cold-start squeal	Rubber too hard / poor low-temp loss	Switch to NR 60–62A or low-temp-optimized HNBR
Braking shudder	Dynamic-stiffness deviation	Choose NVH-tuned version (±10% dynamic stiffness)
Early crazing	Oil/high temp/swelling	Switch to NBR/HNBR; fix oil leaks
Press-fit scars	Tooling misalignment	Use dedicated press cups & guide sleeves

10. Quality, Testing, Certification & Traceability; Differentiators & Cases

· Systems & certifications: TÜV, AEO Advanced (2025-01-09); processes aligned to IATF 16949 (PPAP/IMDS on request).

· Lab capabilities: ASTM D2240 hardness, ISO 37 tensile, ISO 815 compression set, ASTM D429 rubber-to-metal peel, ozone/heat aging, salt spray, NVH rig dynamic stiffness.

· Traceability: unique barcode per piece; full trace for compound/batch and key operations.

· Differentiators: OD micro-tuning, custom hardness, thickened outer sleeve, oil-resistant/high-temp compounds.

· Case: LATAM distributor using 70–75A HNBR version reported improved durability and lower noise claim rate on broken suburban roads (aggregated customer-authorized data; details available under NDA).

FAQ

· Q: Is KD35-34-470 the same as KD3534470?

A: Yes—KD3534470 is the hyphen-less spelling; still verify size and position.

· Q: Is wheel alignment necessary after replacement?

A: Recommended to restore suspension geometry and tire wear.

· Q: How do I pick comfort vs heavy-duty?

A: Smooth roads: 60–65A; heavy load/rough roads: 70–75A or PU.

· Q: Which material for oil or high temperature?

A: Prefer NBR/HNBR; choose HNBR when high temperature and oil coexist.

· Q: Can I use lubricant during press-fit?

A: Apply a thin film on metal interfaces only; never on rubber/bondline.

· Q: Do you offer OD micro-oversize versions?

A: Yes—+0.05 / +0.10 mm OD micro-oversize and tailored tolerance bands.

· Q: Do you support PPAP and batch traceability?

A: Yes—barcode traceability; PPAP and lab reports available.