There are more than 280 million vehicles on North American roads, and many of them are clunking, clicking, or shaking right now. Drivetrains are more complex than ever, so getting an axle complaint right the first time takes more than swapping parts.
In this episode of Shop Owner Solutions, Shop Owner Magazine editor Doug Kaufman talks with Miguel Cornejo, Product Manager at TrakMotive. They cover what’s killing axles today, how to diagnose them by sound and sight, and how to avoid installation mistakes that send cars back to the bay.
In This Episode
- 00:00 – Introduction
- 01:28 – Meet Miguel Cornejo, TrakMotive
- 02:19 – The top three causes of axle failure
- 04:40 – What to inspect when the old axle comes out
- 05:31 – Sourcing the right replacement: OE numbers and VIN decoding
- 07:57 – Problem vehicles: Subaru, Mopar, Hyundai and Volkswagen
- 10:00 – When the axle isn’t the real problem
- 11:13 – Clicking vs. clunking: identifying a failed axle
- 12:36 – Compare old and new before you install
- 13:00 – Choosing a product line: XTT, HDX and Monobloc
- 15:20 – Installation best practices
- 17:57 – TrakMotive tech resources and support
- 19:21 – Wrap-up
Why CV Axles Fail
Miguel names three causes behind most failures he sees:
- Road conditions. Salt and snow speed up corrosion and wear out boots. Commutes are longer, roads aren’t getting better, and one pothole hit at the wrong angle and speed can be enough.
- Vehicle modifications. Lift kits aren’t just for trucks anymore. Changing the undercar geometry puts the joints at steep angles and adds stress that leads to early failure.
- Improper installation, especially the wrong axle. A part that’s close but not exact, or a rushed install, is one of the most common causes of early failure.
Quick tip: Check the boots at every oil change. A torn boot or grease slung around the wheel well usually means the axle doesn’t have long to go.
Diagnosing a Failed Axle
- Clicking or popping when turning: usually the outboard joint. The ball bearings are dry or the joint has failed.
- Clunk when the transmission engages or on/off throttle: usually the inboard joint, from excess slack.
- Shudder or vibration on acceleration: play in a joint, most often the inboard.
- Torn boot or grease spray: the axle has failed or is about to.
When the old axle comes out, inspect the circlip for damage and the splines for missing teeth. Check the transmission fluid for debris. Make sure the axle came out as one complete piece. Any of these can point to a bigger problem.
When It’s Not the Axle
A new axle can’t fix a problem it didn’t cause. Miguel’s examples:
- Older Subarus: The horizontally opposed engine moves side to side, and the factory mounts were soft and wear out fast. Worn mounts can cause heavy vibration on acceleration after a new axle goes in. Check the mounts before warrantying the part.
- Worn engine and transmission mounts in general: The old, worn axle may have been absorbing drivetrain movement. A new, tighter axle exposes it.
- Out-of-balance tires: Often blamed on the axle, and often fixed with a balance.
Sourcing the Right Replacement
Year, make and model only gets you part of the way. Manufacturers share one chassis across several vehicles, and two-door vs. four-door or turbo vs. naturally aspirated versions can use different axles. A YMM lookup can return seven or eight options.
- Best: the OE number from the original axle, for an exact one-for-one match
- Next: TrakMotive’s VIN decoder
- Mopar: the OE number and VIN don’t always match what’s on the vehicle, so go by compressed length and spline count, and call tech support if needed
- Hyundai and Volkswagen: shared platforms make lookups messy, so get the OE number
Before you install, compare the new axle with the old one: compressed length, inner and outer stub lengths, spline counts, and inner and outer seal diameters.
Choosing a Product Line: Xtended Travel™ for Lifted Vehicles
The Xtended Travel™ line is built for lifted vehicles and also works as a heavier-duty replacement on stock-height vehicles:
- Two-piece design with a roller-bearing shaft for about 40 mm of extra plunge travel
- Eight-ball joint (vs. six-ball) with 47° of articulation, compared with 26° on a standard OE replacement
- Upgraded TPE boot that resists tears from debris and off-road use
- Upgraded cold-weather grease, also used in the HD Xtreme™ line
- Fits stock height up to about a 6″ lift. Beyond that, other modifications are usually involved and fitment isn’t guaranteed.
Installation Best Practices
- Never let the axle hang. If you need to step away after seating the inboard side, support it with a bungee or rope. Hanging can separate internal clips and cause failure later.
- No impact guns on final torque. Torque to OE specifications.
- Make sure the circlip fully engages in the transmission.
- Pull the inboard side out with even pressure. It works like a finger trap: uneven force makes it harder.
- Clean the splines and inspect the circlip before installing.
This episode originally aired on Shop Owner Solutions from Shop Owner Magazine, sponsored by TrakMotive. Listen to the original episode →
