Have questions or want to discuss cycling? Join Now or Sign In to participate in the BikeRide community.


Shimano FH-RM40-8 Freehub
#1
I have a Trek 4300 with Shimano FH-RM40-8 for the rear wheel hub which i am trying to service. It makes 1 knocking sound on every spin. Got a few questions:
- Can the Body Fixing Bolt be removed from the Freewheel Body? If yes, how?<br />
- Is there any trick to to remove the balls from the Freewheel Body? Can't seem to dislodge them as easily on the other side.
http://www.paul-lange.de/produkte/shimano/support/explosionszeichungen_archiv/FH/FH-RM40-8.pdf

  Reply
#2
To remove the freehub (Part 14) you undo bolt part 12. This requires a large 10mm Allen key inserted down the centre. Hold the wheel, insert the Allen key down the centre and make sure it is inserted far enough. You will probably have to use the long section and then put a tube or spanner on the short end. (right handed thread)<br />
To remove the balls I just poke around and flick them into the centre QR hole. Push them through and out the other side. (The grease holds them in place.) Some Shimano hubs have seals which can make it awkward to get the balls out but none are shown on the diagram.
You say you get a "knocking" every revolution.<br />
How is this showing?<br />
If it's only doing it when you are pedalling then I doubt it is the freehub.<br />
It may be a cracked ball or ( as happened to me) something completely different.<br />
I thought it was the hub but it turned out to be a slack spoke clicking when the tyre was pumped up hard. (once every rev' of the wheel.)

Ride hard or ride home alone!
  Reply


Possibly Related Threads...

Forum Jump:

[-]
10 Latest Posts
New to the Forum - Introduction
Yesterday 05:38 PM
Would you like a pizza after cycling?
Yesterday 02:10 AM
Hardtail as only bike?
07-12-2026 05:23 PM
Spoke Count Preference
07-12-2026 09:17 AM
Pros & Cons of presta valve vs schrader ...
07-12-2026 03:34 AM
Are you mainly into Mountain Biking, Roa...
07-12-2026 02:20 AM
New around here
07-11-2026 10:53 AM
Favorite MTB brand?
07-10-2026 03:16 AM
29"front & 26" rear? Thoughts?
07-10-2026 03:13 AM
suspicious broken part after service--is...
07-09-2026 02:45 PM

[-]
Join BikeRide on Strava
Feel free to join if you are on Strava: www.strava.com/clubs/bikeridecom

[-]
Top 5 Posters This Month
no avatar 1. Flowrider
27 posts
no avatar 2. meamoantonio
17 posts
no avatar 3. GirishH
17 posts
no avatar 4. ReapThaWhirlwind
15 posts
no avatar 5. Mr. Beanz
13 posts