tiny slivers of metal, burnt gear lube...

[wca_tim]

Most of all I'm looking for an impression from folks that have had a lot of experience with drive repair and changes of how bad it is that I had some very small metal shavings on the magnetic plug when I drained the lube. and some of the lube was burnt looking. Alpha gen one, 1.8 gear, original upper, sei lower. more details below for those who feel like reading... thanks!

My water pump impeller gave out the last time I was out and so I went to change it yesterday and when draining the lube, I found some small slivers of metal on the drain plug magnet (no big chunks) and the lube was much darker than usual. Pulled the cap on the drive and found the upper gears coated in burnt looking lube and with a few dark looking spots on them, but nothing to indicate that they were demaged - no unusual looking wear patters nor anything so blatant as a chipped tooth. The upper roller bearings and cup look fine and aside from the dark, burnt looking lube coating the upper gears, everything looks fine. I haven't had any noises or anything that would indicate a problem with the lower end. I should have checked the lube level before draining, but checkked it a couple of weeks ago and it was full so I didn't think about it. If it was low, it wasn't very low based on what came out.

The current drive is an original 1988 upper that I've run hard and long for several years on top of an SEI lower that I bought a few years ago. There has typically been a little very fine metal "sludge" on the plug and sometimes one or two fine slivers, this time there were more, but not enough that I got any more by filtering the lube. There were also a few lighter colored streaks in the lube (small amount of water?). I changed the lube and sealed, pressure tested and painted the drive just a couple months ago and it probably has 30 or 40 hours of run time on since. This was merc hp gear lube. I had been running mobile one, and never had a problem, but that could just be a coincidence as I've run the merc stuff before. I'm not running a drive shower, but last year had a thermocouple installed for a while to measure the lube temp in the upper housing and even running hard it never got so hot I was concerned. I need to change gear ratios as I'm maxed out on props with the current one and just cryo-treated a new set of hardened 1.62 gears and new bearings, but am not ready to invest the time right now to carefully put an (my first) upper together and was going to do that, a sternjack and possibly a shorter drive if I run across one at the same time when things slow down at work. If my lower is in good shape, I don't want to gernade the upper and need both, so I'm at a bit of a delima. do I:

1. change the impeller, put it back together, pressure test it, fill it and take the kids boarding. Check it often for a while. (I normally have been changing lube at from 25 or so to 40 hours max - I'm hard on things sometimes and know it).

2. order a new upper from sei so when I get the other built I'll just have a good spare.

3. ???

The machine shop owner had really nice alpha drive that they had apprently set up for someone else he said he'd make me a hell of a deal on if I needed one a year or so ago, so either way I'll check to see if he still has it and want's to get rid of it. Was in the same breath he gave me some really nice accessories, ie gaffrig, etc... and offered a hydromotive prop (wrong pitch range), so I'm assuming hell of a deal would be an attractive price.

 

[Don S]

Re: tiny slivers of metal, burnt gear lube...

I've changed gear lube like that on customers boats, if they didn't get them fixed, they usually failed completely withing a few more hours of running.
Those first shiny pieces may have come from a roller bearing that may be starting to fail, the hard facing coming off the rollers. When that happens, they also get very hot, thus the burned oil. It's not going to get any better, and you could end up loosing the whole drive due to contamination as the bearing fails, including gear loss.
I would drain the lube, seperate the upper and lower, then turn the ujoint shaft and feel for any rough spots while turning. Remove the raw water pump and do the same with the lower. This is just to see if you can feel anything, not a full test. For that you need to pull the upper and lower apart and inspect bearings and gears.
It's just a matter of time before it fails completely.

 

[wca_tim]

Re: tiny slivers of metal, burnt gear lube...

I've changed gear lube like that on customers boats, if they didn't get them fixed, they usually failed completely withing a few more hours of running.
Those first shiny pieces may have come from a roller bearing that may be starting to fail, the hard facing coming off the rollers. When that happens, they also get very hot, thus the burned oil. It's not going to get any better, and you could end up loosing the whole drive due to contamination as the bearing fails, including gear loss.
I would drain the lube, seperate the upper and lower, then turn the ujoint shaft and feel for any rough spots while turning. Remove the raw water pump and do the same with the lower. This is just to see if you can feel anything, not a full test. For that you need to pull the upper and lower apart and inspect bearings and gears.
It's just a matter of time before it fails completely.

Thanks Don!

I'll take the kiddos to do something elsethis afternoon and do what you suggest. I have a suspicion it is something in the upper and maybe that I caused it if the lube got a little low (or lets be honest here, I know that an alpha drive borders on being a consumable the way I'm using it). if both upper and lower turn smoothly, I'll pull the upper apart and hope i find the source of the problem there. If I can isolate the source of the issue to the upper, I'll go ahead and get a new upper from sei and then use this upper (which is freshly painted has nice driveshaft, new ujoints, etc...) to build my first one when I have time.

If I put a new upper half on this lower and then the lower goes, is there a big chance it'll ruin the new upper? I would think that's a lot safer than the other way around, but just haven't broken enough of these to know (thank goodness).

I appreciate the benefit of your experience!

(ps. where's the cheapest place to get the tools to set up the shims in the upper? I've been balking at spending the asking price for them...)

 

[Don S]

Re: tiny slivers of metal, burnt gear lube...

If the upper is the cause, the metal was on the drain plug on the lower. That means the metal had to go through the lower to get there.
This is what happens when just an upper or just a lower get looked at and repaired. The old will contaminate the new.
Dissasemble and inspect both the upper and lower.

 

[wca_tim]

Re: tiny slivers of metal, burnt gear lube...

If the upper is the cause, the metal was on the drain plug on the lower. That means the metal had to go through the lower to get there.
This is what happens when just an upper or just a lower get looked at and repaired. The old will contaminate the new.
Dissasemble and inspect both the upper and lower.

Thanks! Not the answer I wanted to hear... but the one i expected...

I'll stop out at Joey's shop tomrrow to see if they're still got a whole drive I can buy for an attractive price to get back on the water (take daughter and her friends tubing and boarding for the rest of the season), reprop accordingly and then find someone to clean out the lower on this one. Even if the guys at the machine shop would do it for me, I doubt they want to mess with these any more and I know they're always plenty busy with their core business. I'm not even sure who in the area to take it to, but will stop out at one of the shops where I often buy parts and talk to one of the techs. I've spoken with one of them several times when he's been helping at the parts counter on the weekend and had a favorable impression. I'm not sure I'm ready to invest in the tools needed to reassemble a lower correctly at this stage (or ever). I'm thinking that when daughter gets another year or two older, I'll put a v-6 back in this boat for her and her friends to use without me and look for another, more focused, project for me (this engine in small inboard hydro? maybe something in the 25 foot class with a blown big block? or even a really fast little outboard tunnel hull set up?). Sorry to ramble / think outloud. type toooo fast.

Enjoy your day! and thanks again...

 

[jtybt]

Re: tiny slivers of metal, burnt gear lube...

I agree with everything Don said.

Did you by any chance check for bluing of the bearings and/or gears? That's a sure indication of overheat. Did the oil have a burnt smell?

Best thing to do if you have the time is disassemble everything to flush and clean everything and reassemble. That wouldn't require re-shimming or the need for a shimming tool.

A non recommended short-cut is remove the drive, pop the top an pour diesel into the drive as you turn the drive shaft to try 'n flush the drive. Paint thinner(mineral spirits) will also work and give you a better idea of what is being flushed. Of course, you have to re-flush with drive oil before re-filling with drive oil.

 

[wca_tim]

Re: tiny slivers of metal, burnt gear lube...

thanks! I haven't looked carefully at the gears in the upper yet, but I won't be a bit surprised if they show signs of overheat. the lube that was really burnt looking was mainly on the upper gears (I didn't idle for long on the way in so I doubt things had a lot of chance to mix). I brought the upper roller bearings and cap in the house rinsed them down with acetone and dried them and they looked good - some wear, but no discoloration, unusual wear or damage was apparent.

Don't know about the smell - I don't have any sense of smell.

not nearly so worried about taking the upper apart as the lower. at this point I'm pretty much assuming the upper is toast and that the lower is what I would need to disassemble and thoroughly clean out - and that's what I don't have the tools for. I'll pull the upper apart tonight and clean the gears up for inspection, etc... If I determine that's the source of the damage, then I'll order a new upper and drop the lower off to have it cleaned out.

either way I'm going to check on the 1.5 ratio whole drive tomorrow. I've got plenty of props that will work with it and it would be good to have another spare now anyhow.