The 934CV Axle

Is the 934 CV Right for You?

The 934 CV axle isn’t for everyone. While it requires a bit more effort to install, it provides unmatched durability and peace of mind—something I'll explain further in this post.

I chose the 934 CV after hearing countless stories of CV failures. From my understanding, most failures aren’t due to shaft breakage, but rather inner cup binding, which causes the outer cup to fail and leads to bigger issues.

Why the 934 CV?

The 934 CV axle is another aftermarket option available in stock and custom lengths, much like other upgraded axles. What makes it appealing is its impressive articulation capability, handling up to 18 inches of wheel travel.

In my case, I run the JD Fabrication 934 CV kit on my 2004 4Runner with their +4 long-travel kit and King 2.5x8 coilovers. While the setup is rated for 14 inches of travel, I’ve limited it to 12 inches for simplicity.

Installation Challenges

One of the biggest hurdles with the 934 CV is installation. As seen in the photos, the subframe requires modification, and a filler plate must be welded back in—which JD Fabrication provides.

Another issue is clearance with the steering rack pinion. Factory CVs don’t have this problem due to their smaller inner housings, but when we assembled the 4Runner and tested for binding, we didn’t notice interference until I turned the steering wheel. It was clear something was rubbing badly, and after some inspection, we realized the steering pinion was making contact with the axle housing.

Finding a Solution

Since the 934 CV is relatively uncommon in the Toyota IFS world, finding a fix wasn’t easy. After reaching out to others, I found two potential solutions:

1. Switching to a CVJ or RCV axle – This was out of the question since I had already installed the filler plates and wanted the extra articulation.
2. Custom differential mounts – A solution suggested by 435syota, and while it looked solid, I wasn’t interested in fabricating new brackets.

Instead, I came up with a simpler fix—using U-shaped alignment shims I had on hand. These shims were ¼-inch thick and fit perfectly under the steering rack. Because of their shape, I could easily slide them in by loosening the bolt. This small adjustment gave me just enough clearance to prevent interference, allowing full steering motion without rubbing.

A Permanent Fix

Since then, I’ve developed a more reliable solution, now available on the website for 2nd Gen Tacoma, 4th Gen 4Runner, and FJ Cruiser owners. This premium-grade spacer is an easy-to-install fix that eliminates steering interference, making the 934 CV a more viable option for those wanting maximum articulation and strength.

Check it out in the shop and make your 934 swap hassle-free!