oil sample analysis

[Clamdigsgal]

Hi,
I am looking at a 2009 ranger 25R for purchase and have done a sea trail and had a survey and oil sample analysis done on this vessel. The sea trail went well with smooth operation, shifting etc. This unit has 480 hrs on it and the engine sample came back descent but the transmission (Twin Disc MG-5005A) showed high levels of copper (1654ppm), Iron (245ppm), Lead (36ppm), Tin (78ppm) and Silicon (91ppm). The owner shared with us that they had a collision with a rock at some point and damaged the shaft, propeller and keel. This was repaired at a reliable repair shop and can see no visible sign that any damage had ever occurred. The oil analysis company is not aware of this collision damage and stated that these high levels of metals could be from "break in wear". Could this be the case or should I be concerned that there is damage to this unit?

 

[mjq1987]

I'm assuming the owner didn't do any other samples prior to the one you had analyzed for the survey so there's nothing to compare this one to. I don't know when this reverse gear is considered broken-in, but my unit's break-in period is the first 100 hours of operation. Also, do you have proof that the owner changed the reverse gear oil and filter prior to this sample, or at all?

If the oil has never been changed, I would consider that a potential problem for the reverse gear longevity, but I am not an expert and have no way to quantify it...just goes against the manufacturer's design/maintenance considerations and good engineering practices. If it has not been changed, that could totally explain the elevated levels of wear metals seen in the sample, but the negative effects of having heavily contaminated oil in the gear case for an extended period of operations may be a current/future issue.

If the oil has been changed according to the factory recommendations, I would still consider the elevated levels to be a problem especially since the boat grounded on a rock. Was shaft/engine alignment checked as part of the survey?

I'm sure it's not cheap but you could have a marine mechanic do a borescope inspection to check mechanical wear in the unit.

Good luck!

 

[NorthernFocus]

One off oil samples are of questionable value. However when they are way out it means something. As already mentioned it is possible that the gear oil has never been changed. Rather than pay someone for an inspection that is likely to produce additional questions rather than any answers, why not simply adjust your offer price accordingly and reference the report as reason for doing so. I'd not walk away from the boat if that's the only issue that you're worried about. Fixing/replacing the gearbox is one of the easier and less expensive things to do on the boat.