Vibration at 65-80 km/h — CV joint wear

Tags: #cv-joint · #vibration

Symptom. A violent vibration appeared suddenly, with no prior warning signs, specifically in the 65-80 km/h speed range, and the car pulled to one side under it; the vibration was much less noticeable outside that speed window¹. Over 170,000 km, the owner notes this kind of unexpected repair has come up more than once¹.

Diagnosis and elimination process. The recommended approach is methodical elimination of other possible causes — wheel balance, rotor/disc runout, tire condition — before targeting the drivetrain¹. In this case, a preliminary inspection found the right inner CV joint ("граната") severely worn, with the left side questionable as well¹. The fix combined: wheel balancing, brake rotor machining, winter tire installation, and eventual CV joint/driveshaft replacement¹.

Confirmed by a separate case. In an unrelated report, replacing the complete right front drive shaft assembly (root cause: a defective internal SHRUS/CV joint) eliminated a vibration during acceleration; the part was sourced from ooove.ru at what the owner considered a reasonable price for a complete assembly, and the vibration was gone immediately after installation²³.

Right inner CV joint — part number and fitment caveat. For the automatic-transmission X80, the right inner CV joint (ШРУС) part number is B5CA022520, priced at roughly 23,640 RUB (March 2025) in the Russian market. Fitment of aftermarket CV joints in general is reported as challenging: many aftermarket analogues have tripod-roller sizes or shaft diameters that don't match the original FAW drive shafts, so verify dimensions carefully before ordering an aftermarket alternative⁴⁵⁶⁷⁸.

Internal spline count and dimension research (SHRUS). Community research into CV-joint internal spline compatibility: a Mazda Sedan GG 2.0/141hp (2002-2005) external SHRUS, part MA-44A44, has 28 external splines, 32 internal splines, 62mm hub diameter, 92mm ABS-ring diameter, 27mm inner-shaft spline diameter, and 145mm total height, priced around 3,200 RUB (RU market, May 2025). Mechanical inspection of an X80 inner drive shaft found 24 splines. One owner attempted fitting the Mazda SHRUS but it failed due to spline mismatch^910111213. Conflict: spline-count measurements disagree between an owner's own count (24 splines) and other data/photo analysis suggesting a higher count; a caliper-measurement photo was inconclusive without a scale reference.

Left CV joint (tripod bearing) failure — replacement strategy. When the left CV joint's tripod bearing fails (producing a clicking/banging noise), replacing the tripod bearing alone is possible but often leads to fitment/compatibility problems. Recommended approach: replace the complete left drive-shaft assembly — part 5CA12560X for AKPP, 5CA02560X for MКПП — rather than the bearing alone, to avoid complications. Available from retailers such as kitzapchasti.ru and autocraft-kzn.ru; one 2019-model price reported was ~20,702 RUB^{14151617181920}.

Left drive assembly specifications — restyle (2019+). For the restyled X80 (2019+), the left drive-shaft assembly measures 700mm total length, with 27 splines at the wheel end and 28 splines at the gearbox end. Part numbers: 5CA12560X (AKPP), 5CA02560X (MКПП)²¹²².

Cross-brand CV joint research and replacement risk. Other Mazda CV joints (e.g. Mazda 6 GG 2002-2007: 648mm length, 28 splines on both ends) can theoretically match by dimension, but substitution is risky in practice — inner CV diameter and spline alignment are often incompatible between models and transmission types. Recommendation: don't attempt a cross-brand substitution without full disassembly and individual component matching; the safe path is the exact OEM X80 assembly (5CA02560X for MКПП, 5CA12560X for AKPP)^2324252627.

Quick-repair dust boot for the external CV joint. A quick-install dust boot (пыльник) for the external CV joint is available with installation clamps included, advertised for fitting without removing the SHRUS from the car. Useful for a fast interim repair without a full CV-joint replacement²⁸.

Mazda 6 GG external SHRUS reported compatible. The external SHRUS (CV joint) from the Mazda 6 GG generation is reported compatible with the FAW X80, usable either as a direct replacement or as a donor part for custom solutions²⁹³⁰.

Mazda SHRUS adaptation via spline machining. A Mazda donor SHRUS can be adapted to fit the FAW X80 by machining down the shaft spline — roughly 0.35mm removed per side from the spline diameter via lathe turning. This requires access to a machine shop with a lathe³¹³²³³.

Complete SHRUS replacement cost. A complete SHRUS (CV joint) assembly replacement cost roughly 8,500 RUB at Russian-market shops as of October 2025 — significantly more than a used donor part, but arrives pre-assembled with no custom machining needed³⁴.

Internal CV joint (tripod) failure — diagnosis and pricing. Symptoms of internal CV-joint (tripod) failure: vertical play felt when the joint is pulled toward the cabin, often with a creaking/clunking sound, while the external joint remains solid. The tripod's three rollers act as bearings and fail as they wear; the part structure is a cross-pin with rollers and a splined collar. Automatic-transmission cars use a tripod-type internal joint. Reported pricing: individual internal joint ~20,000 RUB, complete assembly ~28,500 RUB (RU market, Oct 2025); OEM tripod-only parts available from one supplier at 8,500 RUB with a 3-week delivery. Mazda 6 (B50) internal joints may fit, per unverified community consensus^{35363738394041424344454647484950515253}. Conflict: pricing and sourcing disagree — one report of Mazda B50 tripods fitting after a 3-week special order versus another owner's high pricing (28,500 RUB assembled) versus a third owner's cheaper OEM-tripod-only supply (8,500 RUB), all RU market, Oct 2025.

CV joint (ШРУС) replacement — part number, price spread, and AT/MT tooth-count caveat. Standard part code BM1122510 is confirmed on the KitParts catalog. Reported price spread (RU market, Jan 2026): 8,500 RUB (MasterGTR) up to 12,000-18,000 RUB at other vendors, with reports as high as 22,000 RUB. Critical caveat: the inner/outer shafts differ by transmission type — AT and MT versions have different internal CV-joint tooth configurations despite sharing the same catalog part number. Mazda 6 GG/GH shares a platform with the X80 and may cross-compatible (model MZ37A44 mentioned as a potential match), but vendors report the same catalog number exists in 2+ tooth-count versions, so physical inspection/measurement is required before purchase. One vendor (Василий, MasterGTR) requires VIN + transmission type + a photo to confirm the correct variant. Outer CVs are more standardized across variants; inner CVs are transmission-specific^{54555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100}. Conflict: compatibility reports are contradictory — one user claims a Mazda-sourced CV matches the native X80 CV exactly, others remain skeptical without direct physical comparison; the community consensus is that measurement/testing is required before committing to any cross-brand part.

OEM CV joint restated — pricing and Chinese-supplier sourcing (automatic, pre-restyle). OEM CV joint for the pre-restyled automatic-transmission X80: part BM1122510, priced 8,000-8,500 RUB in the Russian market (Jan 2026). Available from Chinese suppliers (e.g. via Chita), with delivery via SDEK costing roughly 1,000 RUB (RU market, Jan 2026)^{101102103104105}.

Mazda CV joint cross-brand alternative — lathe modification required. Some Mazda CV joints can be fitted to the X80 with modification: the shaft diameter typically needs to be turned down by roughly 0.05mm on a lathe, since Mazda parts have a slightly smaller spline diameter than OEM (measurement needed to confirm fitment on each specific unit). Community members have succeeded with this modification, but it requires precision machine work and post-fit testing^{106107108109110}. Conflict: results vary between owners attempting Mazda alternatives — some succeed with lathe modification, others report uncertain results; overall community preference is OEM parts if the budget allows.

Intermediate shaft bearing — Mazda compatibility, unconfirmed (low confidence). A separate, brief inquiry asked whether the intermediate shaft bearing (a bearing supporting the automatic-transmission driveshaft assembly, distinct from the CV/tripod joints already documented on this card) can be sourced from a Mazda equivalent. The response received suggested checking the specific transmission model before assuming compatibility, but no confirmation either way was reached in this exchange — flagged here as an open, unverified question rather than a resolved cross-compatibility¹¹¹¹¹².

Right outer CV joint part number — independent confirmation from the second Telegram group. A separate community (FAW BESTURN X80 group) independently confirms the same BM1122510 part number already documented on this card for the outer CV joint (ШРУС наружный), specifically for a 2017 pre-facelift, automatic-transmission X80. Cross-brand/analogue fitment availability was raised but not confirmed in this particular exchange^{113114115116117118}.

Inner SHRUS (manual transmission) — sold only as a complete assembly, ~25,000 RUB. A separate report from the second Telegram group (FAW BESTURN X80): after a torn dust boot was diagnosed on a manual-transmission car, the shop advised that the front right inner SHRUS (ШРУС передний правый) is sold only as a complete assembly, at roughly 25,000 RUB (RU market, Apr 2026) — no individual/partial-repair option was available at that shop, consistent with the sourcing difficulty already documented on this card. A community member flagged that when this joint fails, the intermediate shaft and its support bearing (промежуточный вал с подвесным подшипником) should also be inspected, since this component is often overlooked during a SHRUS repair and can itself be a source of secondary damage^{119120121122123124125}.

Drive shafts are NOT interchangeable between manual and automatic gearbox variants. Confirming and generalizing the AT/MT distinction already documented on this card: the drive shafts (referred to loosely as "CVVT shafts" in this report) differ structurally between manual and automatic transmission variants and cannot be swapped between the two. The manual-transmission shaft has a different spline profile from the automatic's. The right intermediate shaft also differs between the two gearbox types — the two parts look visually similar but are internally different — so identification requires physically checking the spline configuration rather than relying on visual inspection alone^126127128.

Right-side CV joint (tripod/ШРУС) spline configuration — manual transmission. Detailed spline spec for the right-side, manual-transmission CV joint: 24 internal splines (sometimes reported as 26 — treat as an open discrepancy), 28 external splines, and a 44-tooth ABS ring. The right drive-shaft assembly includes an internal CV joint that feeds into an extension/intermediate shaft supported by a bearing. Critical part-number caveat: 5CA02550X is for the manual-transmission right drive shaft — this is a different series from the ...2550 numbers used elsewhere on this card, so verify the spline count physically before ordering, since a wrong spline count will prevent proper fitment^129130131.

Right drive shaft internal wear — vibration in pedals/steering at 65,000 km. At 65,000 km, one owner's right drive shaft developed internal wear that manifested as vibration felt in the pedals and steering wheel specifically under load/acceleration. The wear appears to be inside the CV joint or the shaft itself, causing an imbalance; the repair requires shaft replacement — consistent with the load/speed-dependent vibration pattern already documented at the top of this card — confidence: medium¹³².

OEM CV-joint retaining-ring undersizing, and Mazda Tribute CV-joint experience. A separate, detailed thread on OEM vs. Mazda-donor CV joints: the OEM CV joint may ship with an undersized retaining ring, which can allow the joint to pop out of its seat when the steering is turned to full lock. A Mazda Tribute (2000-2007) CV joint is reported to be a close physical match and can be installed, but has developed unexplained spinning/slipping issues in at least one case. The Mazda Tribute's retaining ring (smaller diameter) can be swapped onto the OEM joint, or vice versa, as a workaround for the ring-sizing issue. OEM replacement cost: roughly 8,500 RUB (RU market, Aug 2026). On teardown, if only the external CV joint is damaged, the internal joint can usually be reused — it is disassemblable and can be separated/reassembled with care (a precision job, explicitly not a job for an angle grinder)^{133134135136137138139140141142143144131145146147148}. Conflict: the Mazda Tribute CV joint is reported by one owner as "almost compatible" but caused an unexplained spinning issue after installation; another owner reports a successful swap after modifying the retaining ring. Community takeaway: the exact OEM joint remains the safest choice despite the ~8,500 RUB cost (RU market, Aug 2026), given these mixed Mazda Tribute results.

Media

Close-up photo of a used CV joint showing the spline profile

Caliper measurement photo of the drive-shaft spline diameter

Photo of the installed right-front drive shaft assembly, confirming completed replacement

Additional photo of the drive shaft replacement

Product listing screenshot showing right inner CV joint (шарнир привода внутренний правый) part B5CA022520 for the automatic FAW X80, priced 23,640 RUB, with disassembled CV joint component photos

Photo related to the OEM vs. Mazda Tribute CV-joint retaining-ring comparison and teardown

Additional photo from the CV-joint teardown/inspection discussion

Additional photo from the CV-joint teardown/inspection discussion

Related pages

• Drive shafts, CV joints & axle seals
• High-speed vibration and CV joint wear
• X80F catalog: chassis part codes
• Drive shaft vibration and CV joint repair
• Engine mount wear increases vibration

Sources

This page is compiled from 148 community messages. Every fact carries a numbered reference to its original author and message.

Last updated: 2026-10-29