TheSamba.com :: View topic - Constant problem w/ rear pass side CV axle breaking from hub

Thu May 28, 2009 3:44 pm

Greetings, fellow Vanagon owners!

I consider myself a somewhat seasoned Vanagon owner, as I've had a few of them, from Air cooled, H2O, to diesel; I am really at wits end regarding my 82 CA air cooled Westy: I havent been able to drive it for a distance longer than 3 miles for about 4 YEARS now, as everytime I get it "fixed", my Constant Velocity (CV) axle on my rear passenger side KEEPS breaking off from the hub! You know the 6 bolts that hold the CV axle to the hub? No joke, I literally break 3 bolts at a time after only driving around just 2 or 3 miles! It happened again last night, but THIS time it was AFTER I replaced the ENTIRE rear suspension on that side- including the entire axle hub assembly, which is bolted on 3 places (the rear shock absorber and the two in the front section of the IRS (Independent Rear Suspension) assembly. I thought THAT would have solved the problem- I WAS able to roll around town for about 40 miles THIS time, until it broke AGAIN! I have to constantly carry around at least 6 CV axle bolts on me at all times to replace the broken bolts whenever I try to roll around town! I have the stock Vanagon 14" rims and tires, and not aftermarket rims, so I'm out of ideas why its still doing this... I was told it may be from having too much weight inside, but I dont think that is the problem...

Now, what I HAVE noticed is when I would hit or sometimes gently press on the brakes, I feel a strong THUD or CLUNK from the rear, most likely from that same problem area.. AND its only ever happened on the passenger side- never the driver side.. The 6 bolts keep coming loose and I constantly need to retighten them with that 6mm allen wrench every few blocks (approx. a 1/4 to 1/2 mile) to prevent them from breaking off again..

Here's what I've done so far:
1) Replaced entire CV axle(including bearings on wheel hub side) 3 different times- same result

2) Replaced my stock wheel rim twice, in case something waws wrong with my rim- same result

3) Tried at least 5 times using lock-washers and threaded the bolts with 'Lock-Tite' (that blue goo you put on the threads of the bolts to keep them from loosening)- same result

4) Most recently replaced the entire axle hub (IRS) assembly- Now after doing THIS I was able to roll for about 40 miles before my CV axle broke off from the newly installed axle hub!

Has any other Vanagon owner had a problem with this? I've only had a problem with THIS particluar one, its never happened with my other ones I've owned.. Its still sitting there on the street as I type until I get my hands dirty with CV grease again to fool with it again... Any ideas? Thanks in advance for any feedback!

Thu May 28, 2009 3:55 pm

Are the axels the same lenth on both sides?
Automatics use different lenth axels, someone might have stuck an automatic axel on there.

Thu May 28, 2009 3:58 pm

Thanks- you are absolutely correct about that with the Automatic CV axles (1 being shorter than the other)- to my knowledge, it seems to be consistent with the correct size- BUT I'll have to remove it again and find out 4 sure... Thanks 4 bringing that up!

Thu May 28, 2009 4:02 pm

Yea, if it's got the short one on there, you might be breaking the bolts because it can't extend to it's full lenth of travel.

Thu May 28, 2009 4:48 pm

also bolts may not be tight, may not be strong enuff; threads may have grease or debris in them

Porsches use a special toothed washer (Schnorr) in theirs - do the VWs use that? If so, they must always be replaced of the bolts will loosen and likely break once they are loose.

Thu May 28, 2009 5:12 pm

20yrs ago, One of my weekend offroader friends had a very similar problem...When He'd solved it, He told me that,he must have bent the flange somehow,previously....and now his CV was rocking in the flange and loosening the bolts.
Is it possible to spin the axle and check for runout on the flange??

Thu May 28, 2009 7:44 pm

Thanks 4 all the helpful suggestions, my new friends! :lol:

Goffoz- I have a question 4 u: Regarding that weekend offroading buddy of yours, I just need a little more clarity on that flange he was speaking about; Did he say where that flange was located? For example, was it in the axle hub? The transmission itself? Or was his CV axle bent? Excuse my ignorance, I'm just feeling my way around here, being that I'm boldly going where no mechanic of mine has gone before...

Randywebb- I've tighened my bolts extremely tight, using a ratchet with the 6mm socket & extension to fit inside the head of the bolt- the tightening DOES help, but only by lasting perhaps at the most 30 miles instead of 3 miles.. As far as the Schnorr washers, I suspect that VW also uses these, too, just like many 70s and 80's VWs and Porsches would share virtually the same door handles (I learned that from being in the junkyard and noticing the 944s, 924s, and I saw a 911 also that had very similar pieces.. Anyway, the washers didnt seem to make a difference in my particular situation, I was told this same info by my buddy who owns a local VW parts shop, and to no avail, same result...

Mightyart- I just got back from the other side of town where my Westy is currently marooned- I didnt wanna lug all my tools on foot and the local bus, so I got a ride to take my tools over there so I can take the bus back over there and work on it with all my tools to get it to where I can roll it to where I can really work on it... I hope you're right about that auto tranny CV axle possibility- it makes a lot of sense, and being that I used to have an auto Vanagon I remember comparing them side to side and seeing the difference... I'll check it out once I get back over there..

Thanks 4 the gr8 ideas...

Thu May 28, 2009 8:07 pm

I have no idea what can cause your problem, but i have cv bolts that go loose too. one of the bolts on the outer rear joint i broken with a bit sitting in the hub (is that the right name for the part the cv bolts to?) and they all go loose but much slower than yours. Apparenly the bolts needs to be stronger than regular bolts, an torqued to 45nm.

And yes, porche and vw has a lot of similar parts, 930 cv's bolts straight on vanagon's, man use them on syncro's to gain travel and strengths.

Thu May 28, 2009 8:55 pm

Are you using a torque wrench? These bolts need to be extremely tight. Using a torque wrench would make sure you are getting them tight enough.

Good luck

Fri May 29, 2009 8:30 am

jizae wrote: Thanks 4 all the helpful suggestions, my new friends! :lol:

Goffoz- I have a question 4 u: Regarding that weekend offroading buddy of yours, I just need a little more clarity on that flange he was speaking about; Did he say where that flange was located? For example, was it in the axle hub? The transmission itself? Or was his CV axle bent? Excuse my ignorance, I'm just feeling my way around here, being that I'm boldly going where no mechanic of mine has gone before....
I didn't actually see the damage...He just told me about it
...and your post struck me as being almost exactly the same symptoms.
His problem was located,where the CV bolts to the axle stub...apparently its possible to distort/bend that surface..somehow?...and then you get a rocking motion with each rotation of the wheel.

Fri May 29, 2009 12:02 pm

I dunno re Vanagon, but on a Pcar 911 you need to do ALL the following to make sure the CVs are done right:

1. inspect wrenching fixture & threads of all bolts - replace if subpar - yes, the 911 bolts are a high strength type - 12.9 DIN NEVER use some hardware store crap.

2. clean bolts with brake cleaner & same for female threads in the flange - I use Q-tips - there must be NO grease in there -- NONE. Do NOT use Loctite or anything else.

3. ALWAYS use new Schnorr washers

4. 911 uses "moon plates" - may need to use them; replace if torn up

5. MUST use a torque wrench and put an accurate torqu on the fasteners.

you need to find out what VW specs. for this - NOT always what some PO put on there now.

Bolts are cheap - just buy all new if in doubt - buy real ones not crap substitutes.

Good Luck.

Fri May 29, 2009 1:57 pm

A really stupid question, but is the CV assembled correctly? Does it articulate freely when it isn't attached to the flange? It _might_ be possible for an incorrectly-assembled CV to be bolted on...

Fri May 29, 2009 2:03 pm

Once again, my new buddies, thanx so much 4 the assist on this!

As I type, I'm about 2 head over to the other side of town right now and investigate/troubleshoot whats going on with these symptoms with my CV axle constantly breaking bolts/coming off from the hub..

ReluctantArtist- Thanks again 4 that tip- I hadnt used a torque wrench- I'm gonna see if I can get one today- I only used traditional ratchets & sockets...

ThorAlex - Thanks too 4 the 45nm torque wrench suggestion- you & ReluctantAlex are right on target with this so thats what I'm gonna do.. I'm embarrased to admit this, but I've never in my life even USED a torque wrench, not to mention even SEEN one. I'm gonna do the due diligence today and pick one up momentarily... Thanks 4 the tip, too..

Goffoz- I'll let u know later this evening after I head over 2 my Westy if my symptoms match those of your offroading buddy who had the similar issue as me.. That TOO sounds VERY possible...

Randywebb- Indeed, I think I'm gonna double check to make sure that I've been using that 12.9DIN- I'm gonna check up on that today besides the torque wrench... Hopefully I can get the high strength type..

Thanks again everyone 4 all your help.. I'll keep u posted... Jizae OUT :wink:

P.S.: I FINALLY figured out how to put an avatar pic in my profile! I used my monster Vanagon model..

Fri May 29, 2009 2:09 pm

GeorgeL- You know what? I dont believe in stupid questions- If you dont know, then you dont know- I'm gonna try using a DIFFERENT CV axle altogether today, and see if I get the same result- It is entirely possible that two of my regular mechanics may have just been bolting in the same incorrectly assembled CV on over & over again.. I'll keep u posted- jizae OUT

Fri May 29, 2009 2:16 pm

I don't know if my torque wrench has nm on it, but I think the bentley calls for 32 or 33 lbs.

Fri May 29, 2009 2:17 pm

jizae wrote: GeorgeL- You know what? I dont believe in stupid questions- If you dont know, then you dont know- I'm gonna try using a DIFFERENT CV axle altogether today, and see if I get the same result- It is entirely possible that two of my regular mechanics may have just been bolting in the same incorrectly assembled CV on over & over again.. I'll keep u posted- jizae OUT

Well, perhaps silly, not stupid! :)

I hope that the second axle works out. It would be pretty difficult to bolt up a locked CV.

Another question is what happened to prompt the CV replacement. Something is obviously wrong and the preceding action might be a clue.

Fri May 29, 2009 2:40 pm

If something is bent, this sort of stuff will happen.

Axle, stub axle, etc.

All easy to test with the axle out and the van in the air. They have to be fairly out of whack for there to be a real problem.

A binding CV will do it too.

Now you sure you do not have a bad bearing or differential that is having some internal issues?????

If you have the wrong length axle, you may well do the same nasty thing.

If the CV is loose on the axle, you can get binding and damage.

I think little of bolts getting loose. They don't need to be real tight and will tend to fall out. (I have seen Vanagons with one axle on the ground and for sale cheap but I did not want another project.) Just be sure the the threads in the flange are good.

Now it is remote, but the binding my be internal to the CV because your van is lifted or some odd ball stuff like that, but don't seem likely.

Good luck...

Sat May 30, 2009 7:58 pm

This is a good, easy to follow method for rebuilding your cv's to make sure it's done correctly. It isn't hard, but it can be messy!

http://www.relitech.com/cvjoints.htm

Jeremy