Raymarine ST4000 MK2 Wheel Drive - Ball Bearing Size?

[Tpoo]

Does anybody know the size (diameter) of the stainless ball bearings used in the Raymarine ST4000 MK2 wheel drive? I think they are 1/4 inch but if anyone knows for sure, it would be a big help. There's 21 of them and they ride inside a plastic cage. Managed to recover most of them when the unit split apart when I touched it (the two halves don't seem to be secured together very well). But still need to replace a few missing ones.

Anyway, I've searched and searched online to find the size of these bearings and for some reason this information appears be highly confidential <sarc>. Will go buy a set of vernier calipers if I must, but just trying to take the lazy way out right now. Thank you for your help.

Tpoo

 

[Tally Ho]

Sorry….the service manual doesn’t list the size…

https://www.defender.com/pdf/261503_SERV.pdf

Greg

 

[Tpoo]

Thank you, Tally Ho. Therein lies the problem...but I've heard from someone else that they're 8 mm, or 5/16 inches (more or less equivalent),

 

[Tally Ho]

Good luck!

must have been an “oh sh@t“ moment when those bearings bounced all around the cockpit

my older design St4000 doesn’t have ballbearings…


but be careful if you open up the gear box attached to the motor…lots (like 60) little gears in there…don’t ask he how I know ..

Greg

 

[Ron20324]

Get a gauge for measuring drill bitS. Put the ball in the hole that lets it go/no-go. SAVE IT FOR THE NEXT TIME.

 

[Arctic Pro]

I must be missing something. Why not measure one of the balls you saved? A cheap micrometer would be best but you can eyeball a tape measure for reasonable accuracy. You're not looking for 1/1,000th accuracy here.

 

[Ron20324]

Take the ball to a tool store. Measure with the most expensive tool they have. WRITE IT DOWN ! Put the tool back on the shelf. Go get a beer with the savings.

 

[Morgan donor]

Contact Raymarine?

 

[siberydws]

Does anybody know the size (diameter) of the stainless ball bearings used in the Raymarine ST4000 MK2 wheel drive? I think they are 1/4 inch but if anyone knows for sure, it would be a big help. There's 21 of them and they ride inside a plastic cage. Managed to recover most of them when the unit split apart when I touched it (the two halves don't seem to be secured together very well). But still need to replace a few missing ones.

Anyway, I've searched and searched online to find the size of these bearings and for some reason this information appears be highly confidential <sarc>. Will go buy a set of vernier calipers if I must, but just trying to take the lazy way out right now. Thank you for your help.

Tpoo

What did you conclude? Are they 8mm 316L stainless steel balls? Where did you source the balls if you did? Thanks!