A
Anonymous
Guest
11 months ago I purchased my GS750 and it was in generally good condition for its age (27yo) but In the past week it developed a weird crunching noise when riding, It was sort of like tapping on plastic with a screwdriver.
Upon deeper investigations today the noise seemed to be coming from the rear wheel, so I checked the obvious, chain tension, brake pads etc, and nothing was detected.
I took the rear wheel off to check deeper inside and I noticed that the outer seal of the sproket mounting drum (drive hub) was noticably perished. I checked the bearing directly below this seal by hand and it was extremely crunchy when moved.
Upon removal of the seal to get to the bearing, the bearing fell to bits before I got it all the way out and there was some rusty matter present along with other crunched up metal from the bearing.
So it seems that I have found my "noise".
My diagnosis: The outside seal failed due to perishing which allowed water to penetrate into the bearing, and whilst the bearing still had grease, the grease was sort of drying out thus allowing the water to penetrate into the bearing.
Now FYI:
The Suzuki workshop manual refers to these bearings as:
right wheel bearing,
left wheel bearing,
sproket mounting drum bearing (and seal)
Ok now, In my case the left and right wheel bearings both feel fine, but for the sake of a few extra bucks, and whilst its out anyway I have decided to "go all the way" and will do them also!
My close inspection of the cush drive rubbers shows that they are fine, not hard and brittle, and not soft and mushy.
And the annoying part is that it seems this has been silently happening for some time, I checked everything else whilst the wheel was off, and I also discovered that the rear sproket has some noticable chips in the outer edges so I also decided to replace BOTH sprokets and chain.
The part numbers of the above items are as follows:
Right wheel bearing (disc side):
NSK 6204DU (it has a dust seal incorporated into it)
Left wheel bearing (sits in below the drive hub):
KOYO 6204Z (It is a standard sealed bearing and you could replace it with the NSK 6204DU)
I have ordered the drive hub bearing from my local Suzuki dealer because there was no numbers visible anywhere on it and when I get it I will post the manufacturer and part number.
The outside seal (on the hub) was also ordered from suzuki dealer as my bearing supplier can't locate one with the correct meaesurements.
Its measurements are 33mm ID, 62mm OD, and 7mm thick and the closest the bearing shoppe had was a 32mm x 62mm x 7mm so it would have most likely been too tight on the axle shaft.
I will post the seal and drive hub bearing part numbers early next week after I get them.
What I learnt from this is: When I buy something old and get it home I will ALWAYS check all the wheel (and fork etc) bearings and repack them!
Hope this helps you avoid this potentially life threatening problem!
Regards,
Andrew
Sunny Downtown Nanango
QLD
Aus
Upon deeper investigations today the noise seemed to be coming from the rear wheel, so I checked the obvious, chain tension, brake pads etc, and nothing was detected.
I took the rear wheel off to check deeper inside and I noticed that the outer seal of the sproket mounting drum (drive hub) was noticably perished. I checked the bearing directly below this seal by hand and it was extremely crunchy when moved.
Upon removal of the seal to get to the bearing, the bearing fell to bits before I got it all the way out and there was some rusty matter present along with other crunched up metal from the bearing.
So it seems that I have found my "noise".
My diagnosis: The outside seal failed due to perishing which allowed water to penetrate into the bearing, and whilst the bearing still had grease, the grease was sort of drying out thus allowing the water to penetrate into the bearing.
Now FYI:
The Suzuki workshop manual refers to these bearings as:
right wheel bearing,
left wheel bearing,
sproket mounting drum bearing (and seal)
Ok now, In my case the left and right wheel bearings both feel fine, but for the sake of a few extra bucks, and whilst its out anyway I have decided to "go all the way" and will do them also!
My close inspection of the cush drive rubbers shows that they are fine, not hard and brittle, and not soft and mushy.
And the annoying part is that it seems this has been silently happening for some time, I checked everything else whilst the wheel was off, and I also discovered that the rear sproket has some noticable chips in the outer edges so I also decided to replace BOTH sprokets and chain.
The part numbers of the above items are as follows:
Right wheel bearing (disc side):
NSK 6204DU (it has a dust seal incorporated into it)
Left wheel bearing (sits in below the drive hub):
KOYO 6204Z (It is a standard sealed bearing and you could replace it with the NSK 6204DU)
I have ordered the drive hub bearing from my local Suzuki dealer because there was no numbers visible anywhere on it and when I get it I will post the manufacturer and part number.
The outside seal (on the hub) was also ordered from suzuki dealer as my bearing supplier can't locate one with the correct meaesurements.
Its measurements are 33mm ID, 62mm OD, and 7mm thick and the closest the bearing shoppe had was a 32mm x 62mm x 7mm so it would have most likely been too tight on the axle shaft.
I will post the seal and drive hub bearing part numbers early next week after I get them.
What I learnt from this is: When I buy something old and get it home I will ALWAYS check all the wheel (and fork etc) bearings and repack them!
Hope this helps you avoid this potentially life threatening problem!
Regards,
Andrew
Sunny Downtown Nanango
QLD
Aus
