Wednesday, March 14, 2012

Vanagon CV Joints and Harbor Freight

I've previously mentioned that Westly's constant velocity (CV) joints were getting a bit clangorous.  The CV joint is an important part of the drive train that allows power to be transmitted at variable angles from the transmission, through the axle, to the wheel.  A CV joint is needed because the mounting of the transmission is fixed, whereas the wheel position may be up, down, turned, positive or negative camber, etc.
The Vanagon CV joint 
The Vanagon drive train consists of a combination transmission and final drive (transaxle) in the rear of the van, ahead of the engine.  From the sides of the transaxle protrude axles, a right side and a left side.  These axles have a CV joint on either end, bridging the gap between the transaxle and the rear wheel hub.  With the manual transmission, the right and left axles are interchangeable. The automatic transmission uses two different lengths.

Two-wheel drive Vanagons use a total of four CV joints each weighing about 4 pounds (the Syncro has four more up at the front differential).  They are the Rzeppa type (invented by a Ford Motor Company engineer in 1926) consisting of two grooved spheres with a large ball contained by a ring in each groove, allowing about 45 degrees of articulation.  The spline in the center accepts the axle shaft.  Each joint is packed with grease and covered by a flexible rubber boot.
The axle, CV joints and boots, ready to bolt in
They are very durable, but do need some periodic attention.  As long as they are in good working condition, they can be rotated every 25,000 miles or so to equalize the wear, checking the grease while they are off.  The main problem is that if a boot is torn at all, water and dirt will enter which eventually makes a useless slurry of the grease - then the joint commences to degenerate.  The imminent failure makes itself known by a cacophony of knocking, particularly during deceleration and turning.  Of course, when they fail they tend to fail big, and in some place like Bummerville, California on a holiday weekend (no personal experience with this).

Some of Westly's CV joints had been replaced, but I wanted to have a fresh start and renew all four.  I checked with my Local Vanagon Expert who told me not to waste my time with pre-assembled axle rebuilds (such as that pictured above), or anything but GKN/Lobro manufactured parts.  I ordered up a kit from Van Cafe which came with all new joints, boots, fasteners, grease, and cookies (for eating, not part of the CV assembly).  This kit fits buses ('68 on) and all Vanagons.

When the kit arrived, my Local Vanagon Expert expertly guided me through removing, rebuilding and replacing the axles with the new parts.  Actually he ended up doing almost all the work while I held the trouble light in position and kept wood in the stove (it was December).  Thanks again - I owe you!

If you're up to tackling a CV joint replacement yourself, Van Cafe has a detailed write up on the procedure.

The first drive was wonderfully quiet and smooth.  After 1,000 miles or so, I re-torqued the mounting bolts to 33 ft lbs with my Harbor Freight torque wrench.

Speaking of Harbor Freight, a new one recently opened nearby.  Any mention of Harbor Freight among those who use hand and power tools is sure to result in a lot of opinions and anecdotal evidence flying around.  Virtually everything in the store comes from China and the quality varies widely.  I heard some good advice about the tools:  "If your life or making a living depends on your tools, you probably don't want to buy them at Harbor Freight".  That said, I have many tools in my shop that I probably would not own except that they were "ridiculously low" priced there.  I understand the political, economic and environmental sides of the debate as well, but don't want to go into that here except to say that we seem to have painted ourselves into a consumer-driven corner with Chinese imports with no easy way of stepping out.

For more thought-provoking discussion about Harbor Freight, check this out.

1 comment:

  1. I buy simple tools at the Freight like breaker bars, ball-joint pullers, rags. I would never buy a micrometer or a chop saw from there, I'd be afraid it might blow up and cut me in half. They do have some cool ratchet set parts I'd never seen before...