Axle or Drum Leak?

[Steven McWilliams JR]

Hey everyone,
My car was recently put together and gone through, and last weekend after coming off track, I noticed oil on the bottom of my tire, and there was a trail coming from the axle or drum down to the ground/tire. Is this gear oil somehow getting down the tube from the transmission? I don't want the oil to mix with the bearing grease and ruin a bearing. Is there any reason for this, or any simple fix? It's not leaking a whole lot so I'm going to go ahead and race Jul 17-19, but wouldn't mind solving the problem before then.

Thanks,
Steven

[fv195]

there is a seal at the end of the axel. biggest problem is gear oil on brake shoes, makes them grabby

[Dietmar]

Steven:

My advice is always free- what you do with it is up to you, but I would definitely fix the leak NOW! It will not go away. Only the brakes on that side will go away (stop working) as gear lube and brake shoes do not mix.

Sounds like one of many possibilities- seal, small "O" ring, spacer, axle nut not tightened, axle nut over tightened and the small shim is distorted.
I would take it apart.

Dietmar

[billinstuart]

As usual Dietmar is correct. Gotta have those o-rings positioned properly. It took me a few months to get the hang of assembling the bearing/seal stuff correctly, so I went to the bearing retainer set-up with the external drain hole to prevent lube from getting on the brakes.

[Steven McWilliams JR]

Ok, thanks guys, I'll check it out now, could one cause be from over filling the trans?
Just wandering

Thanks,
-Steven

[Dietmar]

Steven:

One could hope for overfill being the cause, but it is not.

Before you open anything, check for a bent axle - jack up the offending axle side and turn the wheel. Look to see if the drum gets closer to the backing plate as it turns. Also, check to see if the splines on the drum have opened up- the axle nut will be loose after you pull the cotter pin. If neither of these is obvious, look beyond the bearing retainer at the seal(s) and the outer spacer. A worn (rusted) spacer can cause a leak.
If you run into a problem, give me a call (after 9am). The number is at the top.

Dietmar

[SR Racing]

Ok, thanks guys, I'll check it out now, could one cause be from over filling the trans?
Just wandering

Thanks,
-Steven

Absolutely. Your fluid level in the trans should be about 1 inch below the fill hole. The VW manual indicates to fill to the bottom of the hole. However, you will get your trans much hotter and make 1.5+ G turns. The fluid will fill the axle tubes and some will drain out the drain holes in the axles retainer onto your tires just as you described. I would replace your rear axle seals in any case at this point. They are about the cheapest thing on the car. And you will always want to carry spares.

[Dietmar]

Steven:
Not sure which "drain holes" Jim is referring to in the "axles retainer", but if it is the hole in the backing plate, then you could have the bearing retainer that has the drain hole and employs a slinger ring inside the bearing retainer. Early backing plates did not have drain holes as the bearing retainers do not allow for the oil to leave the sealed area. If your leak is coming out this hole in the backing plate, then a new seal and/or "O" ring is in order.

If filling the trans to the hole and thereby putting more oil in the axle tubes COULD cause a leak, then every buggy or off-road VW ( with large tires for ground clearance) and POSITIVE camber would have a leak - this is not the case, at least not the ones that I have worked on; so I stand by my original statement that too much oil is not the cause of your leak.

Either way, you should determine the cause and fix it before the next event.
Dietmar

[brian]

I'm with Dietmar on this one. I recommend filling to one inch below the fill hole, any more will spit out the back of the tranny. At the speeds we run the oil is really splashed around and the tranny will have plenty of lube. When installing a new axle seal always put some grease or oil on the slide on inner race to prevent tearing the seal when dry and make sure the race does not have a wear groove where the seal rides.

[Steven McWilliams JR]

OK, I jacked up the offending side and spun the wheel, the drum did not get closer/further to the backing plate, and the axle nut was not loose when I took the cotter pin out.
THus, I beleive this is from over filling, we did put a whole lot of oil in, I am going to take the drum apart tomorrow and inspect it. can I get the O-rings from any local hardware/automotive store? I also beleive the wheel nuts were too tight, they were torqued at 75. I loosed them up a bit and set the car down, I'll check to see how much leaked out tomorow.
I did not slide the car too hard, although I did spin, I didn't hit any bumps or impact anything, which leads me to beleive that a bent axle is not the case.

Thanks for all your help, I'll tell you how it goes,
Steven

[Dietmar]

Steven:
Any of the suppliers above will have the seal kit- about $3-$4 or so . All the parts will be included.

Hope this helps
Dietmar

[brian]

As was stated before, overfilling will NOT cause your leak. It's like blaming a leaking drain plug on overfilling. Either the thing is sealed or not. Oil is fed out to the axle bearing and as long as the axle is in a negative camber condition, it will drain back to the tranny. The oil rings are metric and while you may be able to find some that will be close, you'll still need the gasket that goes between the retainer and backing plate. Chances are you can find a seal kit at any professional parts house.

[cendiv37]

Before Dave steps in here I'll steal his thunder

You MUST use a hard washer between the spacer and the bearing. The kits you will get often include a cheap soft thin washer that will crush over time, loosening up the axle nut and causing all manner of troubles. The kits are still useful and include the rest of the parts you need (seal, o-rings and paper gasket). The FV specialist suppliers should be able to supply you with the hard washers you need. These can then be reused with the rest of the typical kits as long as they do not get damaged by a drum getting loose.

Also, the assembly sequence of the washer, o-rings, spacer and paper gasket is not obvious and you can easily put the small o-ring on the wrong side of the washer (it goes on the outside) or the large o-ring on the wrong side of the paper gasket (I think it goes on the inside, before the gasket). The exploded diagrams don't always make it clear so the best way to learn is to get some help and take notes on the order. Someone correct me if I have anything wrong here by memory... I am getting old.

[Steven McWilliams JR]

Thanks guys,
Matt hayes came over and put all new O-rings and seals, and it hadn' leaked yet, so it's all good

Thanks guys,
Steven

[jaymzz]

Before Dave steps in here I'll steal his thunder

You MUST use a hard washer between the spacer and the bearing. The kits you will get often include a cheap soft thin washer that will crush over time, loosening up the axle nut and causing all manner of troubles. The kits are still useful and include the rest of the parts you need (seal, o-rings and paper gasket). The FV specialist suppliers should be able to supply you with the hard washers you need. These can then be reused with the rest of the typical kits as long as they do not get damaged by a drum getting loose.

Also, the assembly sequence of the washer, o-rings, spacer and paper gasket is not obvious and you can easily put the small o-ring on the wrong side of the washer (it goes on the outside) or the large o-ring on the wrong side of the paper gasket (I think it goes on the inside, before the gasket). The exploded diagrams don't always make it clear so the best way to learn is to get some help and take notes on the order. Someone correct me if I have anything wrong here by memory... I am getting old.

So is there an online diagram on how that all goes together? My car is eating seals up left and right for some reason. I thought it was the axles so I replaced them. I am putting new seals in tomorrow and kind of wondering if I have all the spacers in correctly and can not seem to find a diagram anywhere with how it all goes together.

[Dietmar]

Jay:

Short of buying the VW manual for about $100, the best reference if VW's are foreign to you is John Muir's: How to Keep the VW Alive for the Complete Idiot.

In the mean time, Bruce outlined the assembly above.

You should have a small spacer with a bevel that goes on the axle- inside the axle tube. Butts up against the flange on the axle.
Next, drive on the bearing until it is seated, next to the bearing goes the thin washer, then the small "O" ring. At this time, the backing plate should be on the axle tube, put the paper gasket on the backing plate (easier to get the next step done). Use some elephant snot ( sealer). Now put the large "O" ring over the bearing. Depending on the retainer that you have- the one with the drain hole and the slinger inside with the seal, or the earlier style with only the seal, you need to slide the larger spacer over the axle. (With the old style retainer you can put the spacer in later- either way works). Some more sealer on the retainer, slide it over the axle and attach with the four bolts. 45# is good enough.
You said that you were "eating" seals. If you are sure it is the seal, then I can't give you much more info.
Years ago I chased a leak time and again and eventually found the outer spacer had a small rough spot on the bevel (which goes over the small "O" ring by the way) and caused the "O" ring to tear each time. Changed the spacer- no leaks.

If you are running with too much play on the axle tube retainer, this could lead to a leak also. I seem to remember that you changed axle tubes a while back.

Also, there is a third style retainer that looks like the early style but actually fits the IRS suspension. It should not be used for our application as the inside step is different from the swing axle style retainer.

Hope this helps.
Dietmar

[Steven McWilliams JR]

We didn't replace the large washer behind the bearing: we found the large O ring to be ripped, and the paper gasked to be really worn down, so we just replaced the seals and not the washer. It hasn' t leaked yet.
Thanks Matt for helping me out, and everyone else for their diagnosis and tips,
Steven

[SR Racing]

Here is one :

http://sracing.com/Store/FV_Stuff/REF5.jpg

Jim

[jaymzz]

You guys are awesome! Thank you very much.

I didn't end up replacing the housing just beat out the original plates to get it to stop leaking. The local VW shop I have been buying my parts from gave me some German seals to use and told me that other people are having the same problems with the seals I was buying. Everything on my axles is now new to try to get it to stop leaking. From the looks of the diagram I did have a part in there wrong, so thanks for all of your help.

[cendiv37]

Not to further confuse the issue, but, in looking at the reference drawing (Thanks Jim!), I'm confused by two things.

1. The items pointed at by the #1 arrow(s) are the items included in a typical seal kit. By this, it indicates that the thin washer included in the kit goes between the the seal spacer (#6) and the drum. I have never used a washer there.

2. The thin washer I use (and which I believe must/should be a hard washer) is the only part in the diagram that has no label. It appears between the two o-rings in the diagram.

I know that the early, "smoothy" drums had a slinger that went in the position shown for the outer thin washer as shown, but I don't think I've ever seen a washer there on a "later" swing axle drum that has the thicker bearing retainer with the oil drain through the backing plate.

Dietmar, Jim, anyone else, what's your take?

My guess is that as long as it's hard, an additional washer won't hurt. I know from experience it isn't needed. I can see where it might possibly spread the contact load a bit on the softer drum.

[Dietmar]

Bruce:

The drawing shows the use of the bearing retainer with the drain hole commonly found on later assemblies- it is not the open faced bearing retainer that most are used to using.
That "extra" shim that is shown on the drawing is the slinger that goes BETWEEN the seal and the bearing retainer. The seal is installed from the back of the retainer (meaning inside) after the slinger is installed. The slinger is larger (o.d) than the hardened shim between the bearing and the small "O" ring.
Use of this retainer requires use of the backing plate that has a drain hole to function as intended.

Dietmar

[Matt King]

I know that the early, "smoothy" drums had a slinger that went in the position shown for the outer thin washer as shown, but I don't think I've ever seen a washer there on a "later" swing axle drum that has the thicker bearing retainer with the oil drain through the backing plate.

So are the early drums interchangeable with the later ones without changing the style of bearing retainer?

[Dietmar]

Matt:

Use any drum with any retainer.
Dietmar

[1969zeitler]

I am putting my axles back together and I have the type that has the drain hole in the outer bearing retainer and the seal installs from the inside. It also has the slinger between the seal and the retainer. Mine did not have a washer between the bearing and the sleeve. Do I need one? The one in the seal kit looks a little thin as some of you have said.

[cendiv37]

Roger,

You do need the thin washer to put against the outside of the bearing itself, before the small o-ring (as described by Dietmar above). Without it, you will likely have a leak. I just ran into this with a fellow competitor who kept oiling his rear brakes on one side. We added the proper washer and his troubles were over.

The problem is that the thin washers sold in the seal kits are too soft (not so much too thin) and they can actually bend under the pressure of the o-ring as the drum is tightened. Or worse, they can't withstand the compressive forces they receive between the very hard spacer and bearing races and they crush and then chafe, relaxing the axle nut pressure which lets the drum get loose. The cheap ones can be permanently bent just using your fingers. A good one will put up a pretty good fight before yielding (though you don't want to bend it).

Your best bet is to get good ones from a reputable FV supplier or to find a good used real VW part. They don't really wear out as long as the drum doesn't get loose for some other reason.