I went over to Blind Chicken Racing and looked up CV Joints 101. The 914 CV is a slightly modified Type 1 joint. Type 1 shows to have 12 degrees of articulation. Going to update to 911SC rear stubs and hubs requiring 100mm CV joints. Type 4, Thing 181, 924/944 are all 100mm with 22 degrees of travel. VW Bus and Vanagan are 100mm too but with 17 degrees of travel.

Bus CV joints are about 1/2 the price of 924/944 with 5 degrees more travel than the stock 914. Any reason they would not be more than heavy duty enough for the job?

Yes, stronger and cheaper. I don't know but suspect they make the joints with larger angles stronger because they're on heavier cars that generally have more suspension travel. When I put in the Subaru transmission I used 100mm bus CV's on the inside and 914 outers. Idea was to leave a weak link that would break before the transmission, and in fact I've broken a LOT of 914 CV's, never one of the bus's. It's probably protected things but it's been a lot of work, so I'm ready to ditch the 914 CV's on the outside in favor of bus both in and out.

You only need as much articulation as you have. To gain more, material is removed and the grooves are extended. CV's are slightly thicker too.

I run some ridiculous 930 style CV's with 45° of articulation. These are high HP units designed for 4x4 truck front axles. No more breaks for me with 300M cages...

I always go for the stock angle (or more).

When we began selling Type 1 CV's, we used the Meyle units. They did not fully extend. We've found the GKN/Loebro joints have the proper articulation and those are the only 914/Type 1 joints we sell now because of this.

Real world issue? Mark De Bernardi was pulling out of a grocery store parking into traffic. The lot apron caused the CV to hyper extend beyond the Meyle's angle as the torque was being applied to merge into traffic. His cage cracked, causing the CV to fail. He did a "lot" of research as to why and this is when we found the angles were not correct. So, that angle is important... the bus CV's should be more than adequate.

I really liked SirAndy's how-to on using the 944 CVs, but the bus CVs seem like they'll do the trick. Does anyone know if the length of the bus CVs are the same as the 914 Cvs, or does the shaft need to be machined for them as well?

The stock 914 axle MAY NOT need machining according to comparison chart over at Blind Chicken racing. Shows the Type 1 (914) to be 32.14mm thick and the Type 2 to be 32.0 thick. SO, I guess it will be a matter of putting one on the shaft and trying it out.

Maybe DB will chime in and let us know IF he had to machine one end for the set up he is using.

I think the spline count is the same between the Type I CVs and the 914 ones as well. The only difference that I can recall is that you either have to convert the flange over to 6-bolt attachment, or convert the CV to 4-bolts and two roll pins.

I think the Bus CVs may be the same, but I'm not sure.

--DD

Bus Lobro CV joints on the way. We will see how the fit on the stock axle.

I'll look it up but bus CV's are way bigger than T1/914CV's.
Bigger OD and bigger axle shaft.

You might be right, but here's some light reading for you....I'm not doing it

http://www.thesamba.com/vw/forum/viewtopic.php?t=517688

Mark, I will be using 100mm 911 SC hubs, stubs and 915 trans flanges.

Unfortunately I won't help much. With the 901 trans we used stock CV's and axles in and out. Changing to the Subaru transmission kept the stock 914 axles and CV's on the outside, then used the 100mm bus CV's on the insides with some adapter flanges to the Subaru output stubs. Second car kept the stock outer 914 CV's on and resplined 914 axles into the stock Subaru inner CV's. None of that helps with the original question.

From experience the bus CV's are stronger, but I don't think the strength has much or anything to do with the angles, more because of bigger cages and larger diameter balls.

OK, the 100mm bus CV's came in today. Disassembled them to show the difference. Bus CV's are a whole lot stronger all the way around. They will bolt up just like the 944 CV joint conversion that Andy posted in the classic section. They WILL REQUIRE MACHINING same as the 944 CV's. The bus CV is the same as the 944 with less articulation but 5 more degrees than the stock 914. In conclusion they will be overkill for a stock 914 but will let you use the 911 SC rear hubs and stubs along with the 915 axle flanges. The bus CV's are cheaper than the 944 and are easy to come by. Boot kits usually have everything you need for install except the 911 gaskets.

Sweet! Axle components are next on my shopping list for my gold car. This will help the process. Thanks Mark!

Awesome! Thank you!

How about a 70 degree bootless CV?

https://www.instagram.com/p/7nsmpyw4zn/

Probably end up in off the road and military applications.

I have a set of both Bus and 944 CVs with axles and flanges if anyone needs them measured with a caliper.

Brett

914 stock axle shafts are 20 1/4". If I remember correctly the Bus ones are shorter. 944's are short about 1/4" if you use one side of the auto trans axle. Need to re-read the axle thread.

Wondering if this is false economy if not using good parts?

Meaning could a GKN/Loebro Type I CV be just as strong as an EMPI* Bus CV?

*EMPI comes up quite a bit when looking at CV joint failures.

Yep, that is why Eric Shea says he ONLY sells GKN/Lobro.

I didn't have any CV failures until my supplier changed from unbranded to Empi 2 years ago. I changed to GKN/Lobro as soon as the data started coming in from a couple of track drivers.
Wndsrfr installed one of my older (pre-Empi I believe) axle assemblies right before Daytona last weekend and had no issues other than some grease slinging.
Although I never expected my stock replacement axle assemblies to be used in high powered track cars.

I think I can answer that. I have bus CV's on one end of the axle and at different times OEM 914/T1/Lobro replacements on the other. The bus ends don't break, I've only broken the OEM 914/T1/Lobro CV ends. The bus CV's are a lot stronger, and you can see why in the photos up above.

Wow, looks like a Nadella joint that was disassembled, cut in half, and then put back together again.

--DD

Bus CV's are very stout.

I think we must be careful when comparing apple and oranges though. I "always" advise customers going with over 140-150hp to go with the larger CV's. GKN or not, the smaller Type1 CV's are not rated for higher HP applications. Porsche used them with the 914-6 but, that was the "only" six cylinder production car I know of that had such small CV's.

It's an extremely common failure point for modified cars. It's also a common failure on stock cars that are now approaching 46 years of age.

Here's my guide:

Stock to 130HP - GKN/Loebro
Higher HP (above 140-150) - I still like GKN/Loebro but we use 108mm 911 CV's with custom floating axles exclusively.

Ultimate 108mm CV
http://www.rcvperformance.com/product-deta...spx?sku=SI-15RF
Must use a sliding axle but comes with a "no questions asked lifetime warranty".

I have these with 300M cages so I son't think they will ever break.

Click to view attachment

Mike, how much did the axles cost to go with those CV joints?

$110 each side (two different lengths) from Pacific Customs.
http://www.pacificcustoms.com/porsche-930-...moly-axles.html