Speedi-Sleeve for Bowthruster shaft

Paul Osterberg

I know some of yo use a speedi sleeve on the bow-thruster shaft. I'm planing the same but I'm a novice so need some help, what dimension did you use? any specific things I need to consider?
Paul on SY Kerpa SM#259, Lagos, Portugal

Peter de Groot

Hi Paul,
I installed a custom bronze Speedi-sleeve about a year ago. sav-amel was shut down for Covid. I had 30mm seals left onboard from the previous owner. The 29mm FRP amel shaft had some wear marks and it was not perfectly round. The sleeve made sense.

My caution would be to pay attention to the insertion tool. My sleeve went on a little tight, but ultimately seated well thanks to the insertion tool getting it there without distortion . I used RTV behind the sleeve but as you can imagine most of it got wiped off during the insertion process

I’m curious what it will look like at the next service.
In the meantime SAV reopened and I purchased the Amel components

Peter de Groot
LaQuerida SM207
Barra de Navidad, Mexico

Bill Kinney


A speedi-Sleeve can be a difficult fit on the bow thruster shaft, mainly because the sizes can be tough to match.  You need to put an accurate set of calipers on the shaft, and carefully measure the diameter to the nearest 0.02mm.  The diameter of these as manufactured is 30.00mm, but they wear quickly. Speedi-sleeves are only available in discrete sizes, and the shaft diameter NEEDS to match EXACTLY the available sizes of sleeve from SKF.  

With a new shaft, there are speedi-sleeves available that will work for the 30mm diameter.  Unfortunately there are gaps in the sizing.  Right now I am woring on a boat with a shaft size that has worn down to 29.50 mm.  There is no sleeve to fit this.  To make matters worse, this is a bit small for a 30mm seal and a bit big for a 29 mm seal.  

My recommendation in this case was to install a 29mm seal now, and buy a new shaft from Amel.  When the new shaft arrives, install a 30mm sleeve on it, use 30mm inside diameter seals, and it will never wear again.

It's totally a great idea that the bow thruster has no metal parts in contact with salt water--but the wear on the GRP shaft is fast, and significant.  Adding a sleeve is a good idea, but it needs to match carefully with the existing diameter of the shaft.

A caveat to all above:  "Speedi-sleeve" is a trademark name for the product from SKF, the big bearing and seal manufactuer.  There might be others making a similar product in more metric friendly sizes that I am not aware of. If you know of such, please let me know!

Paul Osterberg

Thanks Bill!
i found a sleeve with the inner diameter tolerans 29,31-41, guess not to difficult to adjust the shaft to fit, then use a lip seal with inner diameter of 29,5 mm. had a closer look and found that the leak is at the other end through the screws on the lid, should be easier to fix, i just to for granted it was the shaft, will save the speedi sleeve for later 
Paul on SY Kerpa SM#259, Lagos Portugal