Aquadrive Thrust Bearing: Warm and Whistling

[PhilC]

10 year old Aquadrive unit unit (B20 or 30?) engine hours 1600, 150hp VW marine engine. Noticed a whistling noise having developed that appears to be coming from the thrust bearing under higher revs (engine rpm 2000) and possibly a very subtle bearing rumble. Tested temperature with a digital thermometer and (this is after 16hours straight of motoring) the thrust bearing sitting at around 75deg deg c with the shaft at 35deg c.

Some questions:
Does this sound like the early stages of a bearing failure
Anyone else had bearing failure of these units?
Anyone managed to replace the bearing or is it a new assy from Aquadrive
Possible to do in the water - think I can slide the shaft back if the taper connection can be released although have a face seal (PSS) that might make this a tricky operation.

[PhilC]

So we have removed the the thrust, yet to open it up to look at the bearings. Unit is quite smooth but quite a lot of resistance. Feels like it is running quite a lot of preload. Anyone know where to get information on the bearings used and the preload to set them up?

[DougR]

Current distributor:
Aqua drive USA, a division of Mack Boring

Info@aquadriveusa.com
908-964-5656

[PhilC]

Thanks for the response. Talked directly to the manufacturer in Sweden. Will post an update once more is known.

[Tcubed66]

Just ordered my thrust bearing kit from Hanson Marine Engineering in Maryland. John Mills is who you want to talk to. Expensive item.

[dfelsent]

Hansen Marine is in Marblehead, Massachusetts. Jon is awesome. As are Bob, Fred, and the rest.
Less than a mile from me.
Their support is fantastic too. Call and ask for help. You will get it.

[dfelsent]

Oh yeah. And I had an Aquadrive fail. Bellows burst. Grease all over.
Replaced it (with one I bought from Hansen) and eventually realized the shaft strut was misaligned. The thrust bearing mount was offset. The engine was misaligned. The shaft was bent.
After digging out and rebedding the strut, having the shaft/prop/coupler trued, remounting the thrust bearing and aligning the engine it all ran smooth as silk.
I don’t know, but would not be surprised, if the alignment issues were the cause of the failure at about 2700 hours.
Btw, it was clear that the misalignment was not a factory issue, but later work.

[PhilC]

Eventually we removed the unit to inspect. Bearing was silky smooth, took into local agent, compared to rebuilt unit off the shelf. Felt very similar. So we reinstalled. Interestingly temperature while running under load is still higher than I would like. Yesterday measured at 80deg C. Anyone else used a digital thermometer to check temp on theirs while running? Highest temp I could find is on the aft end, on the periphery of the part of the thrust attached to the shaft.

[botanybay]

Originally Posted by PhilC

Eventually we removed the unit to inspect. Bearing was silky smooth, took into local agent, compared to rebuilt unit off the shelf. Felt very similar. So we reinstalled. Interestingly temperature while running under load is still higher than I would like. Yesterday measured at 80deg C. Anyone else used a digital thermometer to check temp on theirs while running? Highest temp I could find is on the aft end, on the periphery of the part of the thrust attached to the shaft.

Hummm, Mine is "just warm", definitely can keep my hand on it without issue. I had a note around somewhere from the guys at Mack Boring who gave expected temperatures.

[PhilC]

Originally Posted by botanybay

Hummm, Mine is "just warm", definitely can keep my hand on it without issue. I had a note around somewhere from the guys at Mack Boring who gave expected temperatures.

Thanks for your response,

The main bearing carrier is 'warm' but the flange on the shaft (the bit thats spinning) cannot be checked by hand unless the gearbox is put in neutral and the shaft stopped. Is it possible that the flange on yours is also hot (80deg)?

Phil

[botanybay]

Originally Posted by PhilC

Thanks for your response,

The main bearing carrier is 'warm' but the flange on the shaft (the bit thats spinning) cannot be checked by hand unless the gearbox is put in neutral and the shaft stopped. Is it possible that the flange on yours is also hot (80deg)?

Phil

I will definitely check. I am touching the carrier as you note. Planning on heading over to Catalina in a couple of weeks and so should have 3 hrs of good motoring (unless there is wind).

In my case I have a Perkins M90 driving a 2:1 reduction drive with the engine running about 1800 RPM to make 7 knts or a shaft RPM of about 900. I am swinging a 24" Maxprop and pushing about 30 Tons of boat.

Are you able to get a good shot of it with an IR Thermometer? Are you checking it from the forward end or aft end. (i.e. the end with the CV Joints or the Shaft End)

[PhilC]

Are you able to get a good shot of it with an IR Thermometer? Are you checking it from the forward end or aft end. (i.e. the end with the CV Joints or the Shaft End)[/QUOTE]

yes, good access for IR thermometer. I'm checking it from the aft end, shooting my IR thermometer along the shaft from just above the stern tube onto the spinning flange.

Would really appreciate knowing that my bearing is actually abnormally hot.

[KlausMortensen]

Originally Posted by PhilC

Thanks for the response. Talked directly to the manufacturer in Sweden. Will post an update once more is known.

I have just replaced bearing in my CVA20200 unit and found out its just a normal wheel bearing.... Purchased a SKF VKBA 1439 bearing and installed it.... Did some more investigation and found out the CV joints are type 15 from the vendor GKN ... Rubber flex is also available from GKN....

[davil]

Originally Posted by botanybay

Hummm, Mine is "just warm", definitely can keep my hand on it without issue. I had a note around somewhere from the guys at Mack Boring who gave expected temperatures.

======================================
4 years cruising, always warm to touch (using my hand) not enough to call it hot.
Always concerned about temp as I installed the flange with epoxy and did not want the epoxy "melt"
Of course, the specs define how much of an angle is within tolerance.

[PhilC]

Quite a lot of motoring over the summer due to some large high pressure systems we passed through. About 300 hours in total. Temperature of outer edge of thrust flange consistently around 80deg.