A1 hub failure

[moliver]

Hey guys I have about 3.5 hours of track time on my 16valve Scirocco and the front axle nut on the passenger side loosened up a bit....caused the wheel bearing to be a blit slopy. I tightened it back up and it took care of the looseness in the wheel bearings. Here is the question, is this the first sign of a hub failure? If not what is the warning sign of a hub failure?

[joeg]

Could be if you are certain the nut was tight before you discovered the problem.

A good suggestion is to replace the bearing (and thoroughly check the hub).

Good luck.

[moliver]

I am not exactly certain how tight the axle nut was initally but I never felt an slop till last weekend after a session, the next session it rained so I was not pushing the car. This weekend I was searching for the slop and discovered the axle nut was a bit loose, tigtened it up and the slop went away. Now it feels fine.

Thanks for the comments/suggestions.
Mike

[RSTPerformance]

On our Audi's we tighten (or check) the axle nuts at least once every weekend of racing... we try to replace hubs and bearings at least twice a year... we have had hub failure and found that it is not a pleasent experience... sometimes just before it goes you can "smell" it overheating... (I have never smelt it however my brother smelt a weird smell and pulled into the pits once.... he was lucky to make it back to the garage...) my suggestion is to keep an eye on it... If you have to tighten it again you might want to consider replacing...

[moliver]

Do you guys tighten the nut to the proper torque or do you put as much torque on it as possible(long lever and people standing on it)?

Mike

[OTLimit]

The procedure here is to check at least once every weekend, with a long bar and a decently weighted person on the end of it (>190 lbs is pretty good). If you change the hub, we check after every session until the nut doesn't move anymore, and then back to routine checking.

We change hubs before major events, and the take-offs become emergency spares. We haven't had a failure in quite a while.

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Lesley Albin
Over The Limit Racing
Blazen Golden Retrievers

[RSTPerformance]

We tighten the nut to the proper torque.

Raymond

[Bildon]

All I can add to the Albin's (correct) procedure is to use a top grade synthetic grease (Swepco, Mobil 1, RedLine, etc) This will ensure that should you over heat the bearing you don't cook all the grease out immediately.

PS- On VWs, the factory torque spec is not sufficient for racing.
Blethen's, you may want to try the above technique if you are experiencing failures. Our hubs/bearings last for years this way.


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Bill Sulouff - Bildon Motorsport (http://www.bildon.com)
Volkswagen Racing Equipment
## 2002 ITB NYSRRC Champs ##

[Rick Phelps]

Originally posted by moliver:
Hey guys I have about 3.5 hours of track time on my 16valve Scirocco and the front axle nut on the passenger side loosened up a bit....caused the wheel bearing to be a blit slopy. I tightened it back up and it took care of the looseness in the wheel bearings. Here is the question, is this the first sign of a hub failure? If not what is the warning sign of a hub failure?
I am told that really is no fool proof way to id an incipient hub failure. I had one at Kershaw over Memorial Day at relatively low speed. Before it broke, I was having brake pedal softness (almost no pedal ) then bam! No brakes, and not much drive as it effectively shears it, even with a quaife. Kershaw has good run off areas, thankfully!
Change the hubs after each 3- 4 race weekends to be safe. Torque with an extender and a big guy on the end each race weekend, Per BSI ! I was very lucky!

Rick

[Greg Amy]

<font face=\"Verdana, Arial\" size=\"2\">Do you guys tighten the nut to the proper torque or...</font>

Hub/bearing failures was a consistent problem in the Rabbit Bilstein Cup. The solution was to buy a 3/4" drive breaker bar and appropriate socket, a very long pipe, and find the biggest, meanest, heaviest guy to stand on it prior to each session.

I did the same thing on the SSA Shelby CSX and never had a failure.

GregA

[Chuck Davis]

Originally posted by joeg:
Could be if you are certain the nut was tight before you discovered the problem.

A good suggestion is to replace the bearing (and thoroughly check the hub).

Good luck.

[Chuck Davis]

Having fought this problem for a long time I did the following.
I made washers that were 1/4" thick and slightly larger than stock. I surface ground them to assure they were flat and then had them hardened.
There are several types of axle nuts. I use the nuts that are the pinch style. Using a Dremel tool I ground slots into the end of the outter CV joint. This way you can stake the nut when you have torqued the nut to spec. Along with using Audi bearings & hubs (5mm larger than VW) I haven't had a hub or bearing failure in two years. (You have to have the uprights machined to accept the Audi stuff)
If you need more information e-mail me.

Chuck Davis

[philstireservice]

Originally posted by RSTPerformance:
We tighten the nut to the proper torque.

Raymond

1000ft lbs might just be enough on those suckers...maybe,lol

------------------
Phil Phillips
94 Acura Integra GSR #4
ITS/H3/ST2
www.philstireservice.com
www.imprintedorginals.com

[RSTPerformance]

Chuck-

Is that legal to run larger Audi bearings in a VW??? If so is it leagal for me to run larger Audi bearings (from a differend year/make) in my Audi???

Raymond

[Bill Miller]

The front hubs on an A1 VW have been a known weak link for several years now (they're documented in Greg Raven's book). I use the 'tweak it as much as you can' rule. At home, I have a 3/4" impact gun w/ 150 psi and 80 gallons of air behind it and I make sure I snug it on there good. At the track, I use the breaker bar/pipe/biggest guy I can find method.

At the end of my first season, I had a hub failure. Fortunately, nothing happened other than ruining a stub axle. This was after 4 weekends/6 races. It's pretty cheap insurance to change them out on a regular basis.

Chuck,

I don't think machining the knuckles and using the Audi stuff is legal in IT. I have heard of people getting the hubs cryo-treated (IT legal), and as long as they're torqued enough, they last! Not sure what it costs to get a set of hubs cryo-treated though?

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MARRS #25 ITB Rabbit GTI
SCCA 279608

[metalworker]

I agree with what everybody has said about getting the nut as tight as possible. Your question was is the hub getting ready to fail? YES . I never have seen the nut just come loose. What is usually happening is the hub has broken inside the bearing, and the stub axle(CV Joint)is holding everything together, or the bearing is failing and the two inner races are wearing into each other. In either case you need to diassemble and look. Also look at the stub, make sure its not been stretched, the crashes don't come from the hub breaking, the come from the stub breaking, which is what is holding the whole assembly together.

[OTLimit]

Originally posted by metalworker:
[B]is the hub getting ready to fail? YES.[B]

Yeah, we all forgot to mention this part. When the person on the end of the bar reports that the nut moved, and he shouldn't have noticed it moving at all, then it's time to replace the hub NOW, not later.


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Lesley Albin
Over The Limit Racing
Blazen Golden Retrievers

[Chuck Davis]

Bill,

The rules in IT do not provide for equity...yet. The GCR does require you to have a safe race car. Making mods such as I mentioned using Audi parts for reliability (safety) should never be an issue. Look at the pictures of the A1 cars in this website doing cart wheels.

All, including you who recommend 200 lb. plus torque specs are kidding yourself. Look at the construction of the bearing. Two hardened (and I mean hardened) surfaces matting. 200# is more than adaquate! (Using the synthetic grease as Chris Albin suggests will extend the life of the bearing.) Get or make some good thick flat washers, grind a groove in the end of the stub axle with a Dremel Tool, torque the nut and then stake it....just like Honda does on all of their cars. (They had the same problem with loose axle nuts when they began racing front drive cars.) Your failures will not go away but you'll get to race more weekends without changing out the parts.

The real problem with the early hubs is the transition radius from striaght onto the back surface of the hub. If you reduce that radius it will have more yeild. If you shot pean the surface you will further reduce the tension.

If you choose to be a purest use some early A2 bearings and hubs. You'll have to widen the snap ring groove. Be sure to use the A2 snap rings.

Happy racing!

Chuck Davis

[Bill Miller]

Chuck,

Are you kidding me????

You're trying to legitimize cheating because it's a safety issue???? Take that crap down the road!

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MARRS #25 ITB Rabbit GTI
SCCA 279608

[Rick Phelps]

Originally posted by Bill Miller:
Chuck,

Are you kidding me????

You're trying to legitimize cheating because it's a safety issue???? Take that crap down the road!

Bill,

I have to be with Chuck on this. Where is improving/correcting an known weak point which can result in very serious consequences, " cheating"? I am not talking "philosophicly" but rather " real world".

No rules nurds please!

Rick

[Bill Miller]

C'mon Rick. This is not a case of stock parts being unsafe. If you treat and install the stock stuff properly, and change it out at reasonable intervals, there's no issue whatsoever. I know a Prod race that's got 3 seasons on a set of cryo-treated A1 hubs. And you certainly will see higher lateral loads w/ the slicks than w/ DOT tires.

This has nothing to do w/ being a 'rules nerd'. This has to do w/ flat out cheating, and then trying to justify it because it's a safety/reliability issue.

Don't get sucked in by the rhetoric. This is cheating, plain and simple. I have no desire to race w/ people who take this approach. And Chuck, I'll put you on notice here and now, if I'm ever racing against you, count on getting called to the tech shed!

I can't believe the unmitigated gall of someone that will essentially stand up and tell you that they're cheating and don't give a shit about the rules.

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MARRS #25 ITB Rabbit GTI (sold)
SCCA 279608

[RSTPerformance]

I like Chucks idea...


I know several people who do conversions on the Audi's putting Porche suspension into them... I think that I will need to do that after all I have hub failures... also we have had brake failures in the past so maybe the BIG porche brakes would be legal, since that is a safety hazard... and wait those drum brakes on the rear... those don't work worth shit so that is a safety issue time to put on disk brakes...

In our AS car you can modify several things in the engine with exception the the crank... this means if you get max power out of the engine then after about 20 hours of use the crank brakes... It happens with every AS Mustang... This inevetably puts big holes in the block and oil under the tires... looks like we can change that now also...

Should I continue my list, or has my point been made???


Raymond "Not Impressed" Blethen

[racer14itc]

Apparently there are a lot more prod cars running around in IT than I realized!

http://Forums.ImprovedTouring.com/it/wink.gif

Gotta agree with Bill on this one. Cheating is cheating, no matter how it is rationalized. If the rules don't say you can, then you can't! If something truly is a safety issue, petition the comp board for an exception (Olds Achieva rear hubs for example). Otherwise, do what the rest of us do: maintain the car on a regular basis and swap out LEGAL parts regularly.

MC

[Chuck Davis]

Bill,

You seemed a bit out of shape about my suggestion. Don't get to wacked out 'cuase if you were to make a semi complete inspection of IT cars at a given race weekend I can assure you that 75% would be in violation of the rules. My experience of many many years has shown that the rules winers are the most suspect.

[Chuck Davis]

Bill Miller

I spoke in haste regarding my last reply. I'm a very user friendly guy http://Forums.ImprovedTouring.com/it/smile.gif
With all the stuff that IT racers want changed the question is why don't they just do a Production car? With that in mind would you be in favor of reducing the age limit on IT cars to 1980 and implementing showroom stock rules. Then the whole thing becomes a matter of picking what you think is the best car for the job and making it purely a drivers contest. What 'ya think? The Comp Board would love it!

Chuck Davis

[OTLimit]

Do we have to have this discussion again?

Part of your car selection process should include a list of the deficiencies of the car. Duh. In this case, the spindle issues on the A1 cars is well documented and there are some less than legal "fixes." Please do not try to call every deficiency in a car a SAFETY ISSUE. It gets old, and I for one am tired of hearing it. Anything that you tell me is a safety issue and the "fix" increases the longevity of parts/assemblies immediately becomes suspect. The same reason you don't redline your motor on every shift.



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Lesley Albin
Over The Limit Racing
Blazen Golden Retrievers

[Bill Miller]

Chuck,

Don't try and change the subject. And 'a bit out of shape'? You're damn right I am. When somebody tries to tell me it's ok to cheat because it's a 'safety issue' and increases the longevity of the parts (not to be confused as being the same thing) and it's ok to cheat because 75% of the cars out there are cheating, I tend to get bent out of shape.

Based on your comments on this thread, I have no respect for you whatsoever. And, I will absolutely have you called to the tech shed if I'm at a race that you're in.

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MARRS #25 ITB Rabbit GTI (sold)
SCCA 279608

[Bildon]

Just a note to those of your reading this who were considering racing, or are now too scared to race an A1 Rabbit.

We ran one for 5 years and never broke a hub. I think we changed them maybe twice. Synth grease, mongo torque and quality OEM parts...you'll be OK.



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Bill Sulouff - Bildon Motorsport (http://www.bildon.com)
Volkswagen Racing Equipment
## 2002 ITB NYSRRC Champs ##

[Rick Phelps]

Originally posted by Bildon:
Just a note to those of your reading this who were considering racing, or are now too scared to race an A1 Rabbit.

We ran one for 5 years and never broke a hub. I think we changed them maybe twice. Synth grease, mongo torque and quality OEM parts...you'll be OK.
There are a lot of folks out there who will disagree strongly with you! Including those who have written a book or two.
Good luck, hope your crash will be a minor one! Not if, but when. I guess we could all get a couple of more races out of those old tires as well... but
Run those pads into the backing too. http://Forums.ImprovedTouring.com/it/smile.gif...

[Chuck Davis]

Hi Bill,

I assume from your signature that the number below your name is your SCCA number. If so you're forgiven 'cause you're to young to understand.

Question. Did your Rabbit have a horn that was operational?

Chuck Davis

[RSTPerformance]

My Audi doesn't have an optional horn, but I think I am going to take it out... It is a safety hazard when I am trying to change the oil http://Forums.ImprovedTouring.com/it/smile.gif

Raymond " I think my Audi is a safety hazard" Blethen

After my post I realized that I havn't changed the ooil since last year.... Crap I need to do that!!!

[This message has been edited by RSTPerformance (edited June 17, 2003).]

[Bill Miller]

Chuck,

Again, you try and change the subject. And, it doesn't really matter when you joined the SCCA to know that cheating is cheating. Or did I miss that issue of the ITCS? http://Forums.ImprovedTouring.com/it/rolleyes.gif

And yes, my car has a horn. It is not functional however, since I'm allowed to use any steering wheel, and the one I chose doesn't have a horn button. Don't see anything in the ITCS that requires the horn to be functional, just that it doesn't say I can remove it. And, since I'm allowed to use any steering wheel (except wood), that leave it open if I want a horn button or not.

Nice try!

BTW, it has a washer bottle too!

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MARRS #25 ITB Rabbit GTI (sold)
SCCA 279608

[RSTPerformance]

Ok I am done with my sarcastic posts against Chuck... I think he gets the idea we are not impressed...

NOW TIME FOR A SERIOSE QUESTION...

Would running ducting (from a front air dam/spoiler) to the brakes and wheel hub area keep the hub cooler thus extending its life???

I know in the GCR it states that you can run ducting to the brakes, but doesn't say that you can run them to a "hub" however seems to me that it would be impossible to run it to the brakes and not also be pointed at the hub...

Just a thought??? What do you think.

(I am more interested in if this would help extend the life of the hub, rather than if it is 100% IT legal or not... In the back of my mind we are continually thinking of running production)

Raymond "trying to cool off" Blethen

[Greg Amy]

Raymond, the problem with the VW hubs is not heat, it's mechanical design. The hub has smaller shaft diameters and sharp radii which make it very susceptible to fatigue failure.

Think of it this way: as the car goes into a corner hard the hub is being fatigued, or flexed, just as you would when you are bending a coat hanger, except in the case of the hub it's happening through 360 degrees and not just in a single plane. A crack will inevitably develop in that sharp radius which quickly propagates into total failure of the shaft (hub).

This doesn't all happen in a millisecond; in fact if you were to remove and inspect the hub via magaflux or FPI after each weekend you'd probably catch the initial cracking well before hub failure. Howver, that's not economically feasible, as it's much cheaper to put your hubs on a replacement schedule based on cycles and hours.

Given that this is a problem only in extreme harsh environments like racing the design is quite sufficient for the street; street Rabbits go their entire lifetime without hub failure. But, as in all things racing, this is one case where the cost of regular replacement is far less than the cost of a single failure.

Greg

[LOBSTA1]

Hi All and I too Ran a 1981 itb rabbit on the west coast (burned up at Holtville injctor line broke) anyways I fully agree the hubs are a safty issue and I have seen them fail at the worst times!!! Not on us we would run six-eight weekends and then change them, german oe units, mega toqure then tighten till strip (almost) Sny grease and recheck all the time. Just m 2 cents thanks Glenn

[Mark LaBarre]

I re-pack mine with Mobil 1 synthetic grease, 175 Ft#'s torque and check re-torque EVERY time I check or torque the wheels. I replace them every 10 track day's or so and have had no problems. Even ran a year on a welded diff (2-wheeling through the corners) on a set of season old hubs and bearings.
Mark

[Eric Parham]

I worry about this type of failure, especially since I think I'm the only one I know who hasn't had it. I use the stock A1 hubs, but use a meatier nut (mid '90s 4-cyl style) so that I can put A LOT of torque on the hub. I believe that the meatier nut is IT compliant as replacement hardware. I generally stand (don't bounce) far enough out on the pipe to put 450 ft-lbs on the nut. It keeps the hub from failing, and the only things I've broken are the nuts (but they're inexpensive in comparison). That's what's been working for me, and I'm not that easy on equipment http://Forums.ImprovedTouring.com/it/wink.gif