worn wheel hub

0die

Veteran Member
Joined
Nov 29, 2012
Location
corpus christi, tx
TDI
1996 Passat wagon B4V
changing a bad wheel bearing and I discover that the hub is worn...

the outside half of the inner bearing race surface of the hub still measures 40.0mm

the inside inner bearing race surface of the hub measures 39.7mm and easily slips into the bearing..

somehow the inner bearing race and hub started slipping and wore down the hub...

when removing the axle nut I did notice that it wasn't all that hard to break loose...it's supposed to be 197ft lbs....

is it possible this is the cause and not due to a bearing failure?

 

Steve Addy

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Aug 7, 2002
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Iowa
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97 Mk3
Your pics are only coming through as thumbnails, can't really see much.

You're talking about front bearing carrier? If so those are common, any Mk3 4 cylinder uses the same carrier.

Steve
 

iluvmydiesels

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Nov 21, 2015
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phila area
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AHU
the axle nut has to be a minimum if about 37ftlbs, this is not a driving on torque, or the bearing will go, if the wheels are on the ground and turn. that part of the hub, cannt be sure from the info you give what went wrong. they are not hard to find. in fact the entire 'hub' assembly can be found. may be smart to start with a fresh one, for each side, as a suggestion.
 

0die

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corpus christi, tx
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1996 Passat wagon B4V
37lbs? My Haynes says the axle nut is 197lbs. that is a huge difference. this is the big nut on the end of the CV axle. If my manual is wrong that could be what caused the hub/bearing wear and failure...
 

Steve Addy

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Iowa
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97 Mk3
http://pics.tdiclub.com/showphoto.php?photo=128219&title=worn-hub&cat=all

does this work better? the white stuff on the hub is frost...since it came outta the freezer in anticipation of easier installation...

what's the bearing carrier? do you mean the steering knuckle?
Ah, yes those do wear, replacement is a good idea. I've had worn ones before, they aren't that expensive fortunately

I suppose bearing carrier is synonymous with steering knuckle. VW calls them a wheel bearing housing, I just simplify as bearing carrier.

Steve
 

0die

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corpus christi, tx
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1996 Passat wagon B4V
gotcha...I'd say mine is fine...the bearing carrier and outter race of the new bearing was still nice and tight...

it's the hub/inner race that is loose...the inside part of the hub that is...

what about the axle nut torque? I've seen 195lbs posted here, my manual say 197lbs and I've seen posted here where it's backed off after tightening so the washer barely moves (which isn't a lot of torque)
 

UFO

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A mile high
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2001 Beetle
I just re-tightened the wheel nut on my MKIV, and yes, the manual instructs an initial torque of 200 ft-lbs, BUT then the nut is loosened, then re-torqued to 37 ft-lbs, then tighten another 90 degrees.

So that is tight, more than 37 ft-lbs but perhaps not as much as 200 ft-lbs. On a MKIV, YMMV.
 

Steve Addy

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Joined
Aug 7, 2002
Location
Iowa
TDI
97 Mk3
gotcha...I'd say mine is fine...the bearing carrier and outter race of the new bearing was still nice and tight...

it's the hub/inner race that is loose...the inside part of the hub that is...

what about the axle nut torque? I've seen 195lbs posted here, my manual say 197lbs and I've seen posted here where it's backed off after tightening so the washer barely moves (which isn't a lot of torque)
Bentley talks about two different scenarios for axle nut torque, one without modified wheel hub and one with modified wheel hub. Apparently some early (Mk3 anyway) cars had sealant on the axle where it engaged the bearing, I'm not sure whether this applies to B4 cars or not. I have never seen it on a Mk3 in all my years, but that's not definitive.

Procedure w/o modified wheel hub is:
1) torque to 66 ft lbs
2) torque additional 1/8 turn (45 degrees)

Procedure with modified wheel hub is:
1) torque to 148 ft lbs
2) loosen 1 turn
3) torque to 37 ft lbs
4) tighten 1/12 turn (30 degrees)

I can't say that I have ever really paid attention to this procedure. The best I've done is maybe approximate the first procedure but I can't really confirm that. I've always hit these pretty hard on torque.

As for why the second procedure backs off and then resets to 37 ft lbs, all I can think of is that the first torque to 148 is to set components in position, like when we press bearings to bottom on circlips etc, although this is just speculation on my part.

Also, remember this comes from the Mk3 manual and not the B4, although since they use the same components (carriers, axles and CV's) I would guess the procedure ought to be the same.

Steve
 

0die

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corpus christi, tx
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1996 Passat wagon B4V
I just re-tightened the wheel nut on my MKIV, and yes, the manual instructs an initial torque of 200 ft-lbs, BUT then the nut is loosened, then re-torqued to 37 ft-lbs, then tighten another 90 degrees.

So that is tight, more than 37 ft-lbs but perhaps not as much as 200 ft-lbs. On a MKIV, YMMV.
I better re-read my Haynes...guess I missed that...well I didn't actually read the procedures this time cause I hadn't re-installed it yet...I was still in the process of pressing the hub into the bearing when the wear issue surfaced....

I just noticed that the nut came off very easy so i went straight to the torque specs in the end of chapter and read "197" with no other info...
 

ToddA1

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Aug 3, 2011
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NJ 08002
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'96 B4V, '97 B4 (sold), '97 Jetta (scrapped)
I torque with a 1/2 breaker bar and a cheater pipe. Tighten it up, then lay into it, just a little. Never had an issue with this torque spec.

-Todd
 

iluvmydiesels

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phila area
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AHU
im not sure of what UFO posted, and i wasnt trying for confusion. the info as many/most of us know i take from the shop manual. like i said what i listed, as i said, wasnt for driving. final torque before you go for a drive is aprox 200ftlbs. we have different ways of getting there. i personally while the car is still up on stands, and about the last thing before putting the wheels on, etc, lowering to the ground, is take one of my impacts to that nut, and hit a few times. this is where the minimum of 37ftlbs comes in, theres need to know this if needed. after lowering and such, before driving. i take a 1/2 long breaker and tighten. to finish i now take a 3/4" bar with a pipe and get to it. about 200 either way you look at it.

added:except for very early models(mk1)this method works mk1,mk2,& mk3s
 
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0die

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corpus christi, tx
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1996 Passat wagon B4V
OK, found my Bentley pdf on the hard drive...

1995-1997 Passat:

section 40-2 (page 2 of 82) states 37 ft lbs if reinstalling axle to move vehicle if axle has already been removed in order to prevent bearing damage...this is obviously if you are moving the car around the repair shop, the axle hub is required to be temporarily reinstalled to keep the 2-piece inner race from separating...

section 40-15 (page 15 of 82) states 195ft lbs when installing axle (base suspension, pictures depict 4 bolt rotors)

section 40-36 (page 36 of 82) states 66 ft lbs plus 1/8 turn when installing axle (plus suspension, pictures depict 5 bolt rotors)

section 40-45 (page 45 of 82) states 66 ft lbs plus 1/8 turn when installing axle (plus/5 bolt cars)

So what I'm gathering is the correct axle nut torque is 195 on the 4 bolt wheel car and 66+1/8 on the 5 bolt cars....

Why the UK Haynes says 197 I don't know unless it's a rounding error converting NM to Ft LBS

would this be correct?
 

Windex

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Cambridge
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05 B5V 01E FRF
You are over-thinking this...

Get a new hub, replace the bearing (and CV/axle if the splines were affected) install all the parts and tighten the bejeepers out of that nut (use a new one).

I've replaced countless bearings on FWD cars (VW and otherwise) and never had one come loose at the correct torque.

Install the parts, tighten to 200lb/ft and motor on.

If you are super concerned, go for a decent drive after the install and check the torque on the nut when you get back. Most new axle nuts I've seen have locktite on them, so I think you will be fine.
 
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0die

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corpus christi, tx
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1996 Passat wagon B4V
I'm good with the 195 ft lbs...

original question remains...what caused the hub to wear? Bearing failure or loose axle nut or other?
 

iluvmydiesels

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phila area
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improper installation of the bearing or this hub part. this part may have taken wear previously and wasnt noticed and this is the end result, just a guess.(??). cheap bearing and/or installation. axle nut being loose is a possibility, i suppose, and after bearing went you didnt notice and kept on driving(??).

dont read in to the haynes manual difference, 195ftlbs, to 197ftlbs, a difference you cannt notice with home hand tools. its 195ftlbs, i state about 200. haynes is ok, shop manual is that much gooder. its nice you looked up the bentley pdf, now your getting the info from the right place.
 

Windex

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Apr 1, 2006
Location
Cambridge
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05 B5V 01E FRF
Based on your picture and description that the nut was not very tight, I would say that the bearing race spun on the hub due to the lack of clamping force from that loose nut.

Haven't seen it before on a FWD sealed bearing setup, but have seen insufficient torque on a hub nut cause a spun race many many times on the heavier side of things (HD trucks - bearing torque at 500 lb ft).
 

0die

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Nov 29, 2012
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corpus christi, tx
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1996 Passat wagon B4V
I don't know how tight the nut was since I didn't use a torque wrench while removing...but I'm pretty sure it was well less than the 200# it was originally set with when I last replaced the bearings since I didn't have to work too hard to break it loose...

That said, the hub is a pretty tight fit since it must be pressed in...even if the nut slacked up some, that race "should" have been tight on the hub I would think...I guess even a minute amount of free play would cause it to work back and forth or side to side even just a fraction of a millimeter and slowly wear down the hub shaft and/or race...

it's been driven a few weeks since it started "drifting" to that side...I had assumed alignment got knocked outta wack from a pothole or something...wasn't til I heard the low speed scraping that I inspected and found the "play" in the bearing...running the car in gear on a jackstand with a stethoscope is can hear the grinding inside the bearing
 

0die

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Nov 29, 2012
Location
corpus christi, tx
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1996 Passat wagon B4V
BTW...when using my HF bearing press to remove the old bearing outter race, the big bolt stripped out :-O so I had to beat it out with the BFH and correct size adapter...and yes both snap rings were out and the hub already out as well...

The new bearing went in no problem with a 3/4" threaded rod and nut replacing stripped bolt...
 
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