Turbo CV Joint Belleville washers

zcoker · 01-19-2009, 04:34 PM

To use or not to use, that is the question. I know that there are a few threads about these cupped washers but nothing real specific, just general statements. Some shops claim to eliminate them when rebuilding CV's (Vertex) but before I do, I am missing one of the dam things and will search around before I bite the bullet. I have not seen any official text which states that they can be eliminated, so I am still a bit skeptical. There's too much axle play between the star and the C-clip when they are not in place. Most other shafts (bmw, etc) do not use the Belleville. Just checking to see if anyone has some laying around. The PO on my car had evidently replaced one CV boot/joint and tossed the Belleville washer. My only other alternative is to make one, get one close to spec and then have it machined to the other washer's dimensions...yikes!

930gt-40r · 930gt-40r's Garage

I've never replaced them myself on any of the axles Ive rebuilt. If I remember correctly, the last set I rebuild was on a Boxter S and they were not on there from the factory.

A930Rocket · 01-19-2009, 06:25 PM

I'm at a loss. What is a belleville washer?

mark houghton · 01-19-2009, 06:38 PM

But of course, it must be a washer made in Belleville...what else could it be?

Hopefully your loss will be my gain, as we're both wondering the same thing. I took one of my CV's appart last year to replace the boot, but still???

vmb · 01-19-2009, 07:11 PM

I just did my CV's in November, bought a bunch of these washers (also called schnorr, IIRC) for the reassembly. There may be extras in the box, I'll check tomorrow and can drop one (or how ever many you need) in the mail. If I can't find them, you can buy them from McMaster, same place I bought my washers and CV bolts.

sand_man · 01-20-2009, 04:45 AM

I use them...figured it was cheap insurance.

I bought them from MacMaster.

Hobbsie · 01-20-2009, 05:30 AM

zcoker, are you referring to the serrated washers under the attaching bolts? 8 or 10mm? I didn't realize they were concave.

sjf911 · sjf911's Garage

Schnorr and Belleville appear to be similar and are both radial spring washers that are available as serrated or smooth. The Belleville variant is available through McMaster.

stevie 77 930 · stevie 77 930's Garage

Rebuilt my CV's using the "moon cups" on both inner and outer joints. These cups keep all of the grease contained in the CV joint subsequently the flanges on the gearbox and the axles stay clean and grease free. The schnorr washers are used on the CV bolts. Most rebuild kits include these cups.

vmb · 01-20-2009, 08:13 AM

sorry zcoker, checked the garage this AM, no spares left.

zcoker · 01-20-2009, 02:01 PM

This washer (Belleville) is behind the cv joint star on the shaft itself. It's cupped and is designed to put tension on the C-clip which holds the entire cv assembly onto the splined shaft. Not to be confused with the CV bolt washers; I know about them. I have a pack of 100 Schnorr washers. On the 930 axles, if this larger Belleville washer is not present, there is quite a bit of free play with the entire CV joint. It's size is about 1.2" ID and almost 2" OD, so it is a big washer. I got the part number but Porsche does not have it anymore. So I was just checking around. I'll probably be making some anyway, just like I had to do on a lot of other stuff. Checking here first in case someone might have one laying around to save me some time. If i do get the new ones made, I'll have some extras.

full quack · 01-20-2009, 03:32 PM

The concaved or convexed washer(depending on what side you view it from), is absolutely designed to pre-load the center section and maintain proper tension on the cir-clip (i.e. snap ring). Without it in place there will be end play between the CV center section and the axle shaft shoulder to the cir-clip location. End play here is BAD. It WILL LEAD TO FAILURE of the CV axle shaft assembly, both quickly & badly.
When reassembling the CV axle unit, definitely re-use the big (Belleville) washer. As long as the washer is still "cupped" it will perform the needed function.
You do not need to replace with new, unless the washer is damaged. If the washer is damaged due to wear, odds are so is the axle shoulder that the center section butts up against.

Mark

A930Rocket · 04:01 PM

I've rebuilt my axles several times and replaced them with rebuilt units as well. I don't recall anything besides the C-clip. Why would Porsche discontinue them if needed?

I know there has been debate on the schnor washers, but I've never used them. I do use the concave washers though and mark the bolt with a marker to see if it has moved over time. This has worked successfully over the years.

Early 930's had a gasket for the end if each cv joint to keep the grease in. My 87 has the stamped metal caps.

timc · 01-20-2009, 04:03 PM

I remember the washers coming off the axles on my earlier 911's, but when I did my 930 axles, there were no washers. I torque the bolts, and ck them at services.

zcoker · 01-20-2009, 04:13 PM

Mark, that's my point, what you said but they are not available from Porsche anymore. I've looked, I've ordered them but get denied. I am missing one. Somebody did some garage R&R on my axles at one time and tossed one washer, so I only have three intact. And I don't want to buy new turbo axles because of one missing washer. I've heard that they have to be pressed to seat the clip. No problem. I'm rebuilding the CV's and I am stuck with this washer--Belleville or whatever one wants to call it-- issue. One tech even told me that they serve a dual purpose: the washer, if noted, extends over the cross-hatch on the inboard side of the CV's thus blocking the balls inside. A safety measure, I guess. I can see that point easily when taking out the balls, just tilt the CV enough and they fall out.

My only other alternative is to size the Belleville's with Macmaster-Carr as close as possible and then machine them to spec. At least I have templates to go by.

full quack · 01-21-2009, 12:11 PM

Hey there zcoker,
Those cupped washers are real common in machine tool applications. They are used in milling machine draw bars & machine table ball screws. You may be able to find a replacement at a large bearing supply house that services the machine tool industry.
These cupped (Belleville washers) are REALLY important to be there in the assembly. My car is an 1983 model, so maybe Porsche axle designs, have changed over the years, thus the apparent occurrence of some folks on this forum having them while others do not.
All I know is if yours had they originally, they need to be there now. This is not a Briggs & Stratton engine, you can not leave parts out and expect a good end result.

Mark

zcoker · 01-21-2009, 03:20 PM

Thanks Mark for the tip. I did not plan on leaving them out as some here do. I think VW started that fad. The Bentley also says something about tossing them, or so I've heard.

billjam · billjam's Garage

Quote:

Originally Posted by full quack

These cupped (Belleville washers) are REALLY important to be there in the assembly. My car is an 1983 model, so maybe Porsche axle designs, have changed over the years, thus the apparent occurrence of some folks on this forum having them while others do not.
All I know is if yours had they originally, they need to be there now. This is not a Briggs & Stratton engine, you can not leave parts out and expect a good end result.

Mark

I would love to see exactly what these washers look like against a CV joint.
I know what belleville washers are and I have never seen them on any of my 911s or 930s.
Perhaps all POs got rid of them?
Anyone got a drive-shaft apart for a photo shoot?
Bill

zcoker · 01-22-2009, 12:56 PM

The washer on the bottom/right is the original Belleville from the 930 shaft. The others, well, those are going to look like the originals when I finish with them on the lathe. They all have the correct spring rates and are of the same material. If you can't get 'em, make 'em!

full quack · 01-22-2009, 05:24 PM

Hey there zcoker,
I'm looking to buy a mill & a lathe. Just seems you can not live without them these days.
Damn I miss owning a full machine shop, it's been 4 years since being bought out, and now I'm going through machine withdrawals.
Got a lead on a Bridgeport mill as we speak, wish me luck!
Mark