Reconstructing Constant Velocity (CV) Joints

[safe]

If the flange is thinner then the spline on the shaft is too long. Not acceptable, you should have the correct cv-joint.

[1-ev.com]

I think total length of the axle that what matters... Of course quality of it is the always PLUS...

Originally Posted by safe

If the flange is thinner then the spline on the shaft is too long. Not acceptable, you should have the correct cv-joint.

[safe]

Originally Posted by 1-ev.com

I think total length of the axle that what matters... Of course quality of it is the always PLUS...

The cv should not be able to move on the spline, there it a spring washer there to keep it tight. If the cv is thinner than what should be there the axle can move and wear.

[logray]

First of all, fantastic thread...

Working with an '87 SC G50 trans. Need to replace both boots on one axle. Have a few questions.

1.) My 3/4" drive torque wrench only goes to 300ft lbs. If I go to 300 and try to fudge the extra 39ft lbs does anyone think this would cause problems, or should I rent something that goes to 339. 300t lbs is a huge amount of torque, and in fact my F150 uses that spec on it's spindle nut. Also sourced a new spindle nut since they are single use. From earlier in the thread...

rcecale said he "fudged" the torque... "Unfortunately, my torque wrench only went to 250 ft lbs. Using my cheater bar, I applied the 250, and then used my breaker bar to "fudge" the rest of the torque. I'm confident they are tight enough for spec."

"...Torque Carrera nut to 333 ft/lbs."

Bentley says 339 ft/lbs.

2.) Pressing joints... Pelican book says inner CV joint should "come right off" once the circlip is removed, without mention of a press. Yet earlier in this thread in several places there is talk about having to use a shop press (perhaps only for the outer joint???). I only need to remove the inner joint so I can replace the boots and clean/inspect/repack the joints. Am I going to be stuck here without a press?

3.) Working with an '87 SC G50 trans, should I go ahead and order the Schnorr or NordLock washers, M8x55 bolts, and moon plates? A little confused as to what combo to use. If anyone has a surplus set of kit they would be willing to sell that would be fantastic!!!

Thanks in advance!

[rick-l]

If it is like my 88, the outer joint does not come off and the inner one did require a nudge with a press. I did not have a press of course so I supported it with two pieces of wood and beat the shaft out with a hammer and a piece of wood.

For torque I weighed myself and stood weight x distance out along the cheater bar.

[logray]

Thanks, that makes me feel better about the torque, I've used similar methods in the past. With 300ft lbs plus a little extra, that nut won't be going anywhere.

Ok, so no press to get it off, but what about re-assembly... it sounds like once it's cleaned up it should just slide on or is some coaxing with a hammer also required?

[1-ev.com]

you r correct, but I am talking about total SIZE of the axle, is that matter... while where bolts torque IS appropriate...

Originally Posted by safe

The cv should not be able to move on the spline, there it a spring washer there to keep it tight. If the cv is thinner than what should be there the axle can move and wear.

[safe]

Originally Posted by 1-ev.com

you r correct, but I am talking about total SIZE of the axle, is that matter... while where bolts torque IS appropriate...

Well the shaft/axle length isn't gonna change, never said anything like that.
But using a thinner CV is not acceptable as it can move on the spline.

[Discseven]

Originally Posted by rcecale

...
Porsche says “NOTE: Since the new CV joints have a sheet metal
housing, washers [moon plates] 911.332.191.00 must be used
when installing.” It says nothing about bolt length or Schnorr
lock washers.

Nice one Randy... always wondered about those plates.

[Discseven]

Originally Posted by Nickshu

Got my half shafts out of the box today (from Pelican). They appear to have different CV's on each one!! Contacted Pelican customer service and emailed them these photos:








Can anyone identify why they would be different?? The thinner joint with no seal on it looks most like the ones I took off the car, but neither are a perfect match.

Nick,

I believe the CV on the left is installed backwards. My understanding is the the groove in the CV should always be towards the end of the shaft.

Someone check me on this please.

[proffighter]

This may help:

[nickelplated5s]

Proffighter's diagram (PET) doesn't show the washers, pay attention when you disassemble. I think the Elephant Racing thread shows them. You can also get away with swapping zip ties for the clamps. Track trick from a smarter mechanic than I.

[ClickClickBoom]

Hey,
There is a lot of information in this thread, that's why the entire thread must be read in context. As I deduced earlier, once you depart from Porsche OEM parts there are variables introduced by aftermarket manufacturers, and attention to detail should be used to achieve maximum results. There is also a debate of accounting vs engineering and the resultant effects on assemblies.
There has been been discussion by more learned members on this board about the Porsche OEM choices for these assemblies, and the lack of Schnoor washers in the manufacturing/assembly process. If the early assemblies used the Schnorr washers and had no problems and later assemblies deleted the Schnorr washers and had problems. Draw your own conclusions.
The math is not difficult, the difficulty comes from having to read 19 pages of posts, and the resultant necessity to measure and determine the correct length bolt to be used for the assembly of parts being used.
After spending many hours online, and reading hundreds of pages of technical specifications as well as reading here the opinions of posters who collectively have hundreds of years experience maintaining and building Porsches, it has become clear that the CV assembly, while simple, requires attention to detail for a successful outcome.
It was also crystal clear, that the use of a correct washer and bolt system is essential. The fact that the application uses a 12.9 grade bolt, implies a higher stressed application and the necessity of correct component assemblies.
I made the mistake of treating the CV assembly with a cavalier attitude and was treated to a flat bed tow truck ride home. I have since found hardware religion and am using new 12.9 bolts of the correct length, Nord-Lock NLX washers, moon plates and surgical cleanliness in the assembly process.
eric

[proffighter]

Not to destroy your evaluation, but here is what I have since 10 years and according manual:



Did I said without moons, Schnorrs, etc...?

BTW it's a 930 Turbo '81

[ClickClickBoom]

Originally Posted by proffighter

Not to destroy your evaluation, but here is what I have since 10 years and according manual:



Did I said without moons, Schnorrs, etc...?

BTW it's a 930 Turbo '81

Glad it's worked for you. I suggest you argue with Grady and the others way more knowledgeable than me. I stand by my previous post, it's your car, you may do what you like, I hope it continues to work well for you.

[proffighter]

Well it's more simple to me. Just what Porsche recommends and what my expirience was.

Here is my source (note: For a turbo only!)

[ClickClickBoom]

Once again, if you read the entire thread you might be enlightened. Grady and others far more knowledgable than you or I have weighed in and discussed the merits. Do yourself a favor and read the entire thread, then come back and discuss.

[proffighter]

Originally Posted by ClickClickBoom

Once again, if you read the entire thread you might be enlightened. Grady and others far more knowledgable than you or I have weighed in and discussed the merits. Do yourself a favor and read the entire thread, then come back and discuss.

Well I red the whole thread... How do you know my knowledge?

As I said before, I trust the Porsche manual/parts catalog because my knowledge!

I said clearly that it's in my case a turbo, so 12.9 grade M10 bolts and no dust cover/moons which are softer steel. Therefore the Schnorr washer would be directly be between the bolt and the flange, which is hardened. Schnorr washers are depending on version not made for stronger than 10.9 grade bolts. Conclusion: No function possible. If you don't believe me, check this from Schnorr itself:

SCHNORR® safety washers are available in two versions: the standard safety washer type “S” is available for screws of sizes M1.6 to M36 and of the property classes up to 8.8. For screws of property classes 8.8 and 10.9, higher pretension forces might be necessary. These are covered by our reinforced washers type “VS

[proffighter]

BTW, I am not against washers there in general, but then use some made for the bolt grade like this:

[winders]

In the 930 CV joint application, the M10 bolts torqued to 61 ft-lbs don't need any type of lock washer. The clamping force is sufficient to prevent loosening.

My race car uses 930 CV joints with the M10 bolts with no washers. I check the torque of the M10 bolts before every event and they have never been loose.

The M8 bolts use on other Porsche CV joints, torqued to 34 ft-lbs, are a different ball game. They need some help to prevent them from loosening.

Scott