Knocking from rear end

[MsTaboo]

[IdahoDoug]

Be sure to double check the axle rotation changes if any are made. It's more than keeping the rotation the same, in fact the true desire is to reverse the torque direction on each CV to start wear on a fresh surface. However, this is trickier than you'd think and I highly recommend someone talking to a tech bring in the diagram from the Van Cafe article (unsure if its up on the new website with RMW) showing how to do this correctly.

On the art school in the woods. Wow. Small world. My girlfriend attended that one magical summer. Very cool place with powerful and beautiful memories of things I treasure to this day. Thanks for mentioning it.

Doug
_________________
1987 2WD Wolfsburg Vanagon Weekender "Mango", two fully locked 80 Series LandCruisers. 2017 Subaru Outback boxer. 1990 Audi 90 Quattro 20V with rear locking differential, 1990 burgundy parts Vanagon. 1984 Porsche 944, 1988 Toyota Supra 5 speed targa, 2002 BMW 325iX, 1982 Toyota Sunrader

[gears]

Switch CVs left to right, leave the axles on the same sides.

The knocking on my Syncro Westy comes from worn lower shock mounting bolts (and steel bushing sleeves) on HD rear shocks .. a simple job I've postponed for no good reason.
_________________
aka Pablo, Geary
9.36 @ 146 in '86 Hot & Sticky
'90 Syncro Westy SVX
'87 Syncro GL 2.5
https://guardtransaxle.com

[t3 kopf]

Switching the axles around but leaving them on the same side will not change the direction of force applied. The only way to do it is to change the drivers side axle to the passenger side and vice versa.
_________________
'90 Carat w/ '95 phase 1 EJ22 OBD2 conversion

[gears]

.. which is exactly why you want to leave the axles on the same side, while swapping only the CVs from side to side.
_________________
aka Pablo, Geary
9.36 @ 146 in '86 Hot & Sticky
'90 Syncro Westy SVX
'87 Syncro GL 2.5
https://guardtransaxle.com

[fxr]

[t3 kopf]

The OP has already established he has a manual.
_________________
'90 Carat w/ '95 phase 1 EJ22 OBD2 conversion

[gears]

Yes. I'm not an axle expert, but in dragracing it was well known that changing axles side to side would lead to premature failure. As I often hear of broken axles when off-roading Syncro vans, I have to wonder if those broken axles had changed sides at some time.
_________________
aka Pablo, Geary
9.36 @ 146 in '86 Hot & Sticky
'90 Syncro Westy SVX
'87 Syncro GL 2.5
https://guardtransaxle.com

[IdahoDoug]

Gears,

Was that drag racing with solid axles, or with independent CV type axles? I could see solid axle shafts having been twisted with use, then reversed and they'd perhaps take less energy to "untwist" with torque and then end up twisted in the other direction causing point stresses here and there. And a bang.

On the CV's the purpose is to cause the ball to switch sides in the cage and start wearing a groove in the opposite ramps. So it always made sense to me to do it the way Van Cafe's site specified (including diagrams). It is SOOOOO easy to do this wrong, and I did it once before double checking the diagram and having to move things around.

Gears, you'd appreciate this. Last night my son Dirk (whom you've met) and I finished working on what will be his Supra in the garage by sitting and watching an episode of the Hoonigan's website showing the Donut Garage and cars doing burnouts. They showed in slow mo a perfect example of axle windup and release on an old rat rod. It was cool. Also, a guy in a Porsche 912 with a 6 cylinder stuffed into it shatters a custom aluminum drive shaft. Lots of carnage!!

Doug
_________________
1987 2WD Wolfsburg Vanagon Weekender "Mango", two fully locked 80 Series LandCruisers. 2017 Subaru Outback boxer. 1990 Audi 90 Quattro 20V with rear locking differential, 1990 burgundy parts Vanagon. 1984 Porsche 944, 1988 Toyota Supra 5 speed targa, 2002 BMW 325iX, 1982 Toyota Sunrader

[dhaavers]

[E1]

+1 on the share.
_________________
‘84 Westy, 2.1L with Digijet, 5.43 R+P, GT Gears
"Adding power makes you faster on the straights.
Subtracting weight makes you faster everywhere."
— Colin Chapman

[Wildthings]

What is going to break the axle is the difference between the maximum forward torque and the maximum reward torque on the axle. Swapping the axles side to side would effectively be increasing the maximum torque differential. For a high powered dune buggy lets say the axle can handle only 10,000 full load cycles before it would break, but on a stock van in street use where the maximum loads might be half or even a third of what a dune buggy or off road crawler sees, the number of cycles the axle can with stand might well be in the hundreds of millions or essentially infinite.

Most every rear engine VW out there has had the axles moved from side to side multiple times over the years and there is no epidemic of axles breaking that I have heard of and I don't think that the epidemic will suddenly start tomorrow.

[t3 kopf]

Though I can understand how that could happen, I don't think that anyone in a vanagon who isn't drag racing has anything to fear concerning swapping axles. I would think that the CV joints would be the most vulnerable point on the axle and would give out before the shaft itself. especially on those who are running abnormally high lifts and wheels.
_________________
'90 Carat w/ '95 phase 1 EJ22 OBD2 conversion

[IdahoDoug]

Dhaavers/E1,

Don't say I didn't warn you. If you have never seen this bunch, you will not be able to stop laughing and watching their automotive mayhem. It's Ken Block's (rally champion) garage, staffed by a bunch of auto enthusiasts with a destructive slant. Automotive icons and celebrities are encouraged to stop by with hot cars and do burnouts, or try to get up the loading ramp burning rubber, cross the cargo area, get through a narrow concrete doorway into the shop, spin come back out the door still burning rubber, get back to the parking lot and do donuts in its narrow confines, etc. Its a tiny lot in LA which leads to unexpected drama when they run out of room. You will see engines blown, tires shredded, priceless classics do $50,000 in damage in 3 seconds, etc.

They talk these people into jumping their cars, putting the nose against a concrete wall to burn rubber down to rims, they drag race the length of a shipping container. Things go horribly wrong, usually involving a fully restored Porsche, vintage race car, etc.

Here's the link of the episode with the '55 doing a burnout and you can see the tires grab, release and repeat. What's happening is the axles are twisting and untwisting and the slow-mo lets you see it clearly. Enjoy: https://www.youtube.com/watch?v=j7elRjtVbYM

Doug
_________________
1987 2WD Wolfsburg Vanagon Weekender "Mango", two fully locked 80 Series LandCruisers. 2017 Subaru Outback boxer. 1990 Audi 90 Quattro 20V with rear locking differential, 1990 burgundy parts Vanagon. 1984 Porsche 944, 1988 Toyota Supra 5 speed targa, 2002 BMW 325iX, 1982 Toyota Sunrader

[MarkWard]

In over 40 years, I have never seen a cv axle in a stock application snap for any reason. Not saying it can't happen, but who can be sure after 30 years their CV axles haven't had their rotation direction swapped. I don't think it is something to lose sleep over. You should not place the balls in different ramps when you resassemble the joints after cleaning.
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☮️

[djkeev]

Oh, just great!

Took my Van to the local VW club meeting Monday night (CJVWS) and wouldn't you know it, the Right Rear axle starts knocking on left turns?

Jacked it up, all is tight, no loose bolts or joint play.

I think that I need to pull the axle and regrease the CV's. It has been probably 15,000 miles or more since I redid them. Maybe the cold temperatures?

Anyway.........

Dave
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Stop Dead Photo Links how to post photos

Ghia
http://www.thesamba.com/vw/forum/viewtopic.php?t=392473

Vanagon
http://www.thesamba.com/vw/forum/viewtopic.php?p=6315537#6315537

Beetle
https://www.thesamba.com/vw/forum/viewtopic.php?t=482968&highlight=74+super+vert

[IdahoDoug]

Dave,

Just for grins, buy a $3 needle fitting for your grease gun and try the "shoot grease in the boot" cure. I'd be curious how fast it quits knocking. Within minutes, or a half day of errand running, etc.

Mark,

Your comment about the balls needing to stay where they were is extremely important. I have opened joints (CV and Birfields) greased and haphazardly put the balls wherever on reassembly only to be rewarded with horrendous knocking as the balls wore the ramps to their particular size. They'll shut up but I know perfectly well that's only after removing metal to get them to match and that is now in my fresh grease.

For years now, I use a procedure of marking the ramps and the balls to ensure they stay where they were. The result? Silent joints after regrease.

No mechanic will take the time to do this but for all you DIY'ers I think it's good procedure.

I think this should be discussed and put into an FAQ and I volunteer you to do it!
_________________
1987 2WD Wolfsburg Vanagon Weekender "Mango", two fully locked 80 Series LandCruisers. 2017 Subaru Outback boxer. 1990 Audi 90 Quattro 20V with rear locking differential, 1990 burgundy parts Vanagon. 1984 Porsche 944, 1988 Toyota Supra 5 speed targa, 2002 BMW 325iX, 1982 Toyota Sunrader

[AndyBees]

In 1986, in our 83 Air-cool tin-top driving south on the Cassiar Highway (HWY 37) in north central British Columbia (dirt road then), I began hearing this strange noise that sounded like a helicopter overhead. So, after a quick inspection beside the road, I proceeded on south for well over 100 miles (no other choice) to a little community (New Hazelton) on the Yellow Head (16). I stopped at a Standard Service Station at closing time. The two dudes put the Van up on the rack and greased the CV Joints using a very long needle.... problem solved. $20 donation and I was on my way in 15 minutes!

Then, in the summer of 2014 in Dawson City, Yukon, I had a new made in Germany Lobro CV Joint to begin whacking on my 84 tin top... I removed both axles in the Campground and re-greased them.... no more whacking.

So, hopefully the OP's CV Joints only need some grease, or better yet, just tightening the bolts!

_________________
'84 Vanagon Tin-top, ALH TDI. 1989 Tin-top
1983 Air-cool, 225k miles, 180k miles mine. Seven trips to Alaska from 1986 thru 2003.

[Wildthings]

The CV's on my quite new '91 Multivan started making noise when they had less than 30K on them. Being in a remote location with few resources at this time I managed to come up with a grease gun from one source, a short needle and some plain jane lithium grease from another. The noise disappeared immediately and I didn't every pull down the joints until the tranny failed a dozen plus years later.

[gears]

It seemed we'd see at least one Syncro axle break each year at SyncroFest, back when guys were actually off-roading their Syncros hard (although 4 times as many CV cages broke).

According to Tom Lengyel, "Axles usually break at the inner side of the cv splines, leaving the broken stub in the star wheel of the cv joint. They seem to break on both the inner and outer joints."

I'm betting that Seth saw his fair share of breakage (in his monster off-road Syncro, before upgrading to custom axles & CVs).
_________________
aka Pablo, Geary
9.36 @ 146 in '86 Hot & Sticky
'90 Syncro Westy SVX
'87 Syncro GL 2.5
https://guardtransaxle.com