CV failure?, How can you tell? Options

[JeffBowlsby]

A few questions...How does a CV fail? Is it progressive or instantaneous? Any warning signs? How many miles does a CV typically last before it fails? When it fails, is it catastrophic? Can it cause an accident if you re at highway speeds or underbody damage? Can our 914s run with just one halfshaft...even temporarily?

I understand stock 914/4 CVs are NLA. What is the best recommended solution?

Got photos of a blown CV?

TIA. (IMG:style_emoticons/default/biggrin.gif)

[Eric_Shea]

The clicking sound Paul describes is probably a broken cage. When this happens you are close to catastrophic failure. They will also howl or moan.

Here is the link to the replacements:

http://www.pmbperformance.com/catalog/item...868/3857681.htm

We now use only “Loebro” replacement CV’s as we have found them to be exact spec to the originals.

Previous to using the Loebro CV’s exclusively, we have had two failures over the last three years. One was McMark and the other was Yarin. Both were replaced under warranty.

Mark was pulling out of a parking lot apron and extending the CV while applying torque. Hardly far from normal so it caused a bit of alarm. It just so happened they were on their way to RRC (I still feel bad about that) which brought them through SLC. While here, Andy and Mark examined the replacement Meyle CV and thought it might extend too far. This was based upon Andy’s knowledge and memory of recently putting together the CV’s for his 5-lug conversion. When Mark arrived back home and examined the broken CV, it looked as though it could have been caused by hyper-extension of the cage. We discussed this in great detail and also looked at the self limiting factors of the stub axles and the transmission flanges. The basic conclusion was that it was “kind of” inconclusive but I think all of us left the subject a little leery of the extra extension found in the Meyle joint.

Yarin was the other CV and it was on a car regularly used for auto-crossing with slicks. In that thread we had another member suggest looking at the Loebro CV’s again (we had both side-by-side originally but Mike Mueller, the original machinist, thought they were basically identical).

All this to say; upon comparing the Loebro against the stock 914 CV and the Meyle I decided to incur the extra $5-6 cost for Loebro kits moving forward. They are more consistent and have the exact extension characteristics as the originals. I am confident that we can bring what was less than a 1% failure rate down even further.