Quest for Speed

It's been a while since I posted last but have some Questions for the masses.

I have a 2001 Powerquest 380 Avenger with 500efi's running XR drives on the ITS system. The engines and drives are not the original and were installed last year. I took the boat in for a 100 hour service to have the dealer look over everything before the warranty ran out. The engines/drives have about 60 hours on them. I have changed the engine oil and drive oil 3 times since installed and run Redline Heavy shockproof gear oil. The boat is run at 4,000rpm 60% of the time, 3,500 rpm 35% of the time and 5,000 5%. The boat rarely leaves the water, maybe had a dozen times the drives have come out of the water and I have never hit the rev limiters.

The drives were pulled and there is water in both drives . The mechanic told me that the merc gear lube will mix with the water to help prevent excessive wear in a case like this and that the Redline does not allow the water to mix and will create pockets of water and therefore no lubrication. Both drives have to be reseeled, both need new gears and one needs a new gimbel bairing. I dodged a bullet and merc is covering the repairs (may be worth paying mercs prices if they back their products this well).

I have two questions:

1. Why would both drives have leaking seals with so few hours? Is there something in my driving habits that could have caused the failure?

2. Should I go back to Merc gear lube? Is the Redline more for the racer who tears down often and changes fluid everytime the boat is run?

Thanks, I know someone here will have some insight as to what happened.

Cord

iTrader: (2)

My opinion-stick with the merc green. They manufactured the drive and custom make the oil specifically for their drive. The oil has the properties that they feel are critical for the drive to live. I once put the question to a engineer who worked on developing the bravo drive. He said that they had tested other products. Some products had properties that had definite advantages over the merc product. The problem is that many of the products had disadvantages over the merc oil. But none of the other oils had the optimal combination of all the properties.

P Offshore

I have run lots of hours (100's) with Redline and Merc gear lubes and can't really tell the difference. I have also run over 800 horsepower on these Bravo's without failure; but I have never had water in my gear lube. It seems to me that no matter what gear lube you run until you keep the water out there would be a risk of failure!

nitro/max

I was told theres a update seal on the xr drive. Not sure if this is why the water is geting into the drive. Do you have to keep adding to the drive oil? I think my xr drive is leeking drive oil, there only 8 hours on it.

migpilot

Quest for speed


What year is the ITS and Engine combo. Also how fast is the boat with that setup (curious) Were you getting any drive whine?

I have the same setup (boat and engines) with no apparent problems in 70 hours but there is a faint whine coming from the starboard drive when compared with the port. Not sure if it is a function of drive direction (spinning opposite). I have been running merc green all along. Like you I have changed the drive oil three times and my driving habits are very close to yours.

P.S. was that boat originally powered with a volvo DPX?

Quest for Speed

Migpilot, the system is an 02 and I have no whine from either drive. I did have to add drive fluid to port side the last run before service but did not see any water in the resevoir.

I am running around 81 for top speed but the boat is not yet propped properly. I have run three different sets of props and have not gotten above what I want yet. I am going to go to one of the local prop shops and see if they will let me demo a number of props to find the right set-up. My current set cruise great so I don't want to play with them but they only hit just shy of 5,000 rpm.

migpilot

Quest,

My boat turned out to have a slightly higher top speed running at 5000 than it does now with lab finished 33'S pitched to 31 by merc at 5300. 80 is the best I have seen at 700 feet msl and cold lake michigan conditions

Just drained my drives last night with barely a hint of flakes and clean lube at 80 hours total time. Is it possible that your drives didn't get serviced properly. I am sure our drives were manufactured within week of each other.

Quest for Speed

Thanks. That's why I won't touch the current props I have, don't want to mess up a good thing.


Anyone else have any ideas why water would get into both drives and wrench both sets of gears without tearing up the bearings?

Mr Gadgets

Propshaft seals can pick up some fishing line and let water in. The upgrade seal that was talked about is a new seal retainer for the input shaft. It wont let the seal be forced out of the retainer because it has a lip. Usually the resevoir bottle will need filling if that seal has been pushed forward and leaking.

One thing to do is have the drives presure tested after assembly, some do positive and negative psi to catch a problem..


Good luck

Dick

migpilot

The thrust faces of the gears obviously are at the greatest risk of failure with a lube breakdown with the bearing be able to withstand these conditions longer. I am thinking that your drives may not have been serviced properly allowing for some air to be trapped in the drive. When the drives cooled it may have literally sucked water into the drives. The procedure for refilling is fairly specific about reinstalling the vent plug then continuing to pressure feed the drive to fill the drive monitor resovoirs. This allows the dribble valve to have the proper pressure on each side of it to let the lube flow both way to allow for heat expansion and contraction at the same time making sure there is no air in your drive. What other commonality besides a possible manufacturing defect do the drives have in common.