K75/100/1100 Steering Head Bearing Update

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Discussions everywhere on the topic of K75/100/1100 Steering head bearing alternatives to OEM were a bit confusing to me because I am terrible at putting together a proper search string to find what I need. …. To get to the heart of my problem:  “What ‘numbered’ size Steering Head bearings are in my 1994 K75RT and where can I buy alternatives to the now $125.00 cost of replacements.  There are lots of posts on installation, so I won’t get into that here. 

Motobricks has a short write up here, which did not show up in my original forum search queries (because I apparently can’t “search”):   

http://www.motobrick.com/index.php?topic=1231.0


Chris Harris has a couple of videos on how to do this job here:
 WARNING!  LOTS OF PROFANITY, but he’s a great mechanic:       




Let it be known I’m not an engineer, scientist, journeyman professional mechanic or a competent “searcher” poster or photographer (obviously).  Please feel free to flame and correct this post as necessary.  I perused over many forums to just get at the answer, and I found some data was that incomplete and in at least one case, wrong all together.

The OEM bearing (Per MAX BMW fiche- and it fits ALL K75, 100, 1100 Series and others) is BMW P/N  07 11 9 985 070   Tapered Roller Bearing – 28 x 52 x 16 @ $29.95 each.  HOWEVER, it appears this part number has been SUPERCEDED to P/N 31 42 7 663 941; this part has a NEW AND IMPROVED price of $62.60 each.  $125.00 for two taper bearings?   I have a bearing house near me, but they deal with “industrial bearings” only and apparently there’s a difference between industrial and automotive types, and they couldn’t/wouldn’t help. Lazy counterperson, I suppose.   My local BMW dealer stocks exactly nothing, and there’s not a bike shop in this city I trust to give me any info on a spark plug, let alone possible Japanese bike cross references, so to the internet I went.

According to one blogger’s post, a bearing number of 30205 was declared the correct size.  This is incorrect as the OD and Width are correct, but the ID was 25mm and 28 mm is the correct size for the ID.

I’m doing this write up for the sake of other newbies….as I took that blogger’s info, blindly (why? See ‘unable to search’ above), bought the 30205 bearings without a second thought (stupid), then promptly  installed the cups before checking to see if the cones even fit.  Now non-returnable due to cup installation, it was back to square one.

According to another, a bearing number of 32028 was given; this is incorrect, as that bearing’s ID is something like 144mm !! The number was missing a ‘forward slash’ which proved critical.

25 mm ID is INCORRECT on this 30205 bearing.  Needs to be 28mm.

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This is the OEM steering head bearing I removed (times 2).  They are “Cup and Cone” type tapered roller bearings.

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28mm ID on the OEM bearing.

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Its pretty clear I don't know how to post multiple pics in a post....sorry !!!

BMW used SKF’s  320/28 X/VT108  on my K75, and I assume this bearing brand is what they have as their replacement part ;  ID=28mm OD=52mm Width=16mm.  The “forward slash” is very important between the 320 and 28, as without it you’ll get a very different bearing.  The suffix “X” is vital.  I found little on the suffix VT108; it doesn’t affect function, but it seems to reflect that it’s a tapered bearing, has a chamfer and requires a good quality grease for lubrication.  Add to this if you have additional information.

On the ADV forum there was a lot of chatter about Napa Auto Parts BR32 being a substitute for their F Series bikes…. so I did some research and found these have the same OEM dimensions and that the F series bikes share the same OEM bearing P/N  for the K75, K100, K1100 Series as well. If you’re overseas, Napa is an auto parts chain in the US. I will say they mounted up and fit perfectly.

The product line is “Napa Bearings” for this exact part number, which I’m led to believe is the better quality of the two categories that Napa sells.  Napa lists this bearing as a fit for ‘manual transaxle input shaft-outer’ for some Ford Escape, Fusion, Escort and Honda Civic models.

NAPA Auto Parts BR32  ($26.95 ea.) 28 x 52 x 16…..The box shows “SKF” but ‘NSK Japan’ was stamped on the bearings. 

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Napa BR32 on left – OEM on the right

SKF, NSK, NTN and FAG manufacture bearings in size 320/28 X.  SKF’s number is 320/28 X/Q…. NSK’s number is HR320/28 XJ… NTN’s number is 4T-320/28 X and FAG’s number is 320/28-X.  And of course, Napa Auto Parts BR32 (which is an NSK bearing in an SKF box!)  I was unable to determine if Timken carries this size.  And I’m sure there’s a budget Chinese bearing out there too.

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There is one basic visual difference between the OEM and BR32 and that’s a chamfer on the inner bearing race which will not affect installation or function. These are pressed on the steering stem and the top ‘knurled nut’ from the other side anyway.  I can’t see losing any strength due to the loss of material here. Also, the cage that holds the bearing rollers in the cone is stamped metal on the OEM, and has the appearance of a cast piece on the Napa bearing. These bearings are the same physical size, the picture makes them look different to each other. (see "not a good photographer" above)....

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As to longevity?  The off-road F-Series guys give these the thumbs up.  After all, it is listed as a car “input shaft brg for a Manual Transaxle", me thinks that would be a harsher environment than holding up a front end of a bike.

I found this little gem when digesting the fact that it was going to take 2 weeks (maybe, no, MOST LIKELY more) to get an OEM fork seal locally….(note: fed up,  I have since ordered an OEM seal from another dealer, so I didn’t go this route, but the later model K75,100,1100’s do have SHOWA forks and so do many Japanese models, so do with this what you will….)

Fork Seal Cross Reference for models with 41 x 54 x 11 seals:       
                             http://www.startline.co.za/PDF/19%200-Fork%20Seal%202015.pdf

Here’s a new OEM seal with its markings.  It’s triple lipped and it looks just like a Honda seal……

OEM Fork Seal (from 8/91 – Showa Fork) is: BMW Part Number 31 42 2 312 838…(41 x 54 x 11).  The seal has these markings embossed into it:  NOK BR20031. …41-80….88-4 …..Wiper/Dust cap has BR3420F embossed on it.  I Googled the NOK number and found that several Japanese bikes use this seal, although, for example, Honda P/N 51490-MER-R61 is sold only  as a set with both seal and dust wiper…so you’d probably have to buy two sets to get the wipers to match….or maybe not….

I hope this helps anyone that's wrestling with this type of project........

[mr_10brook]

I installed All Balls brand which I believe were recommended by frankenduck.

 I did watch the Chris Harris videos before attempting and still had a little difficulty and made my own bearing preload tool from a piece of copper plumbing and torque to spec.

I did need to re-tighten the bearings after a few hundred miles with no issues since. Throw away the dust seal they provide and buy the BMW washers/dust cover which are only a few bucks each. (some people reuse, but are very easy to destroy when removing old bearings)

 The total in parts will be around 30 bucks.

http://www.ebay.com/itm/NEW-All-Balls-Steering-Stem-Bearing-Seal-Kit-for-BMW-FAST-FREE-SHIP-22-1024-/161468489310?hash=item2598459e5e&vxp=mtr

[billday]

When I did my steering bearings a couple years back, I accidentally ordered two dust caps. Be glad to mail my extra to anyone who wants it. PM me.

[Scud]

Very useful topic - and the link to the videos, which I watched a few times. This is my first time doing this job - and it was going slowly but smoothly.... till now.

I used All Balls bearings - got the races in the frame and just installed the top bearing on the nut. However, I used the dust seal that came with the All Balls kit. The seal has a rubber outer lip, which I thought seemed like a nice improvement over the OEM. But now it is very difficult to turn the bearing. Is this why it was recommended to not use it? Has anyone had a similar experience? Should I install as-is - or maybe get a new bearing and BMW dust seals for top and bottom? I have not installed the lower bearing yet - pending advice.

Edit: When I slip an old race over the bearing with the rubber dust seal it moves much more easily. Seems like it will work fine - but I am still curious why people say not to use the All Balls dust seals with the rubber.

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You can still use your AllBalls bearings.  Just purchase the dust seals OEM....you'll need 2.

[Scud]

Thanks for the reply. I went ahead last night and used the rubber seals that came with the All Balls bearings. Here's what I found:

When installing the bearing on the top nut (over the rubber seal) it was difficult to turn - it moved freely, but I could tell there was resistance due to the rubber. When I put an old race over the bearing it moved more easily.

I decided to try the lower bearing and seal - figuring I could remove it if needed. This one also offered a little resistance.

However - when I put the triple clamps back on the bike, they moved freely and effortlessly. The resistance from the rubber seal is inconsequential against the leverage of the triple clamps - and will be even less relevant against the leverage of the handlebars.

Conclusion - initially, the rubber seal seemed like it was going to cause a problem, but I think it may be an improvement over the OEM design. It seals the bearing, whereas the OEM design is more of a shield, which relies on grease filing the space between the bearing and the all-metal dust seal.

It's going to be a while till I can give a ride report as I have other stuff to do on the bike first.

I was intimidated by this job, but this thread and the videos made it possible for me to do it.