Z1 Transmission Bearing

  • JT-NZ
  • JT-NZ's Avatar Topic Author
  • Offline
  • User
  • User
    Registered
  • Posts: 8
  • Thanks: 2

Z1 Transmission Bearing

30 Jan 2026 20:20
#921076
I'm helping my friend reassemble his '73 Z1 engine. The output shaft bearing (part number 92045-021) needs to be replaced and we have sourced a new one locally from a bearing supply store which has the correct bearing number - BL305NC3. The original bearing is open on both sides, however, the one we have sourced has a shield on one side. Once located in the half ring, the shield is on the outside of the case. Our thinking is that this should be fine as the open side is still exposed to the engine oil being as it's on the inside of the case.
Can someone confirm if our thinking is ok please ?
The following user(s) said Thank You: willemZ900

Please Log in or Create an account to join the conversation.

  • zed1015
  • zed1015's Avatar
  • Offline
  • User
  • User
    Registered
  • Posts: 3226
  • Thanks: 1913

Re: Z1 Transmission Bearing

31 Jan 2026 02:02
#921083
Just remove the shield.
They are easy to pull out..
AIR CORRECTOR JETS FOR VM CARBS AND ETHANOL RESISTANT VITON CHOKE PLUNGER SEAL REPLACMENT FOR ALL CLASSIC AND MODERN MOTORCYCLE CARBURETTORS
www.kzrider.com/23-for-sale/611992-air-c...lide-mikunis?start=0





The following user(s) said Thank You: asphalt900, Street Fighter LTD

Please Log in or Create an account to join the conversation.

  • asphalt900
  • asphalt900's Avatar
  • Offline
  • Sustaining Member
  • Sustaining Member
    Registered
  • Posts: 1539
  • Thanks: 1031

Re: Z1 Transmission Bearing

31 Jan 2026 02:51
#921084
Ditto what Zed1015 said, just pop it out with a small stout/fairly sharp flat blade screwdriver Ish tool. Question though? These bearings are hard to find in the states from any bearing warehouse! What is the manufacture of the bearing you bought? Also the number "BL305NC3" should have a "Z" added, will be stamped on the box. Z stands for metal shield in bearing lingo. One Z, one shield. Two Z's, both sides shielded. 
The following user(s) said Thank You: StreetfighterKz, Wookie58

Please Log in or Create an account to join the conversation.

  • JT-NZ
  • JT-NZ's Avatar Topic Author
  • Offline
  • User
  • User
    Registered
  • Posts: 8
  • Thanks: 2

Re: Z1 Transmission Bearing

31 Jan 2026 14:51
#921093
Ok, thanks guys.
Asphalt900, I used the bearing number in the parts book, but checking my receipt it is a "BL305ZNR". The brand is NSK and the local guys who are NSK agents bought it in from Australia for me (I'm in New Zealand).
The following user(s) said Thank You: willemZ900

Please Log in or Create an account to join the conversation.

  • Cra-z1
  • Cra-z1's Avatar
  • Offline
  • User
  • User
    Registered
  • Posts: 353
  • Thanks: 275

Re: Z1 Transmission Bearing

01 Feb 2026 09:33 - 01 Feb 2026 09:36
#921101
I buy them from APE, sourcing them on your own may save you some cash but APE has them in stock. I think it's a good practice to replace that output bearing along with the countershaft bearing. They also offer a super heavy duty bearing if you intend to do some racing.
Last edit: 01 Feb 2026 09:36 by Cra-z1.
The following user(s) said Thank You: Wookie58

Please Log in or Create an account to join the conversation.

Moderators: Street Fighter LTD
Powered by Kunena Forum