Tuesday, July 31, 2012

BMW Slash Two wheel bearing pop quiz - Let's play "what's wrong?"

Yesterday, after disassembling the wheel bearing and seals from Randy's Slash 2, I noticed that the wheel bearings needed to be replaced. Today, I obtained four new bearings. New SNR 30204A.

After arranging the parts on my workbench, I began to get confused.

Some of the spacers appeared to be incorrect.

I labeled them with "Wrong part?" 

Three of the end caps that retain the felt washers were mangled and are on order now.

There was also a missing felt seal that is on order. The other felt seals are in good shape.

Two of the collars appeared to be incorrect parts. Here's one:

Maybe someone made this part to replace a missing or damaged part?  Even so, the new part is shaped incorrectly and it has a large gouge in it.

This felt seal arrangement is an early design that was later replaced with a rubber seal system. However to do that, you need to upgrade several other parts. Here's a diagram showing the new style seal:

New Style Seal

From Bench Mark Works site:

36 31 4 038 230--$9.95--seal hub plug late R50/2-R69S
36 31 4 038 243--$25.00--wheel thrust sleeve LHS for late hub plug R50/2-R69S use in 36 31 4 038 272
36 31 4 038 272--$69.00--hub plug late style  R50-R69S requires use of new type sleeve 36 31 4 038 243 and 36 31 4 038 230 seal 

On the brake drum side, You can also eliminate #4, 5 & 6 by using this:
36 31 4 038 259S--$10.00--seal substitute for the felt ring and cover inside wheel RHS R50-R69S

So we are looking at close to $200 to upgrade to the new style seals. I felt that the upgrade was too expensive for this build.

I will order new end caps and seals in the old style, and will instead try to source used parts to replace the parts marked "wrong part?" in my photos below.

36 31 4 038 259F--$2.00--felt ring RHS and inside old style hub plug R50-R69S 
36 31 4 038 255--$6.50--cap for felt ring early wheel hub plug and inner wheel RHS felt seal R50-R69S

Hmm.  What to do!?!

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  1. SHould be easy to make a spacer like the bad part, it looks damaged, if not made wrong. I seem to remember that it is just a tube with accurately machined ends and length, should be easy to get someone to make it. I could do it, but you'd have to come up here...

  2. I think I'll post a note on the Slash 2 list to see if any packrats have any laying around!