Reply
 
Thread Tools Search this Thread
 
Old 18 February 2019, 04:47   #1
Member
 
Country: UK - England
Town: Nr Faversham, Kent
Boat name: C Rider
Make: Avon
Length: 5m +
Engine: Yam 80
Join Date: Jan 2005
Posts: 486
Yamaha F80, water in gearbox

Drained the gearbox for the annual service and found alot of water and the oil was black and gloopy. Is this a diy job to strip, clean, inspect, replace seals and reassemble?
Attached Thumbnails
Click image for larger version

Name:	IMG_0352[1].jpg
Views:	122
Size:	99.3 KB
ID:	128524  
__________________

__________________
Searider - The Best 5.4 x Far
Swifty is offline   Reply With Quote
Old 18 February 2019, 07:24   #2
Member
 
Country: UK - England
Town: Liverpool
Length: no boat
Join Date: May 2015
Posts: 183
Hi Swifty, just working on my yam gearbox also....The oil should be a golden colour so if that oil is only a year old i'd say there's something wearing inside as a result of the water getting in..
There are two screws on the leg side. I'd remove the remaining oil and with a gentle hand pump,pressurise the gear box to 15psi (?). Using bottle of soapy water you'll see the bubbles and hence the culprit leaking seal(s)
The lower output shaft seal is more difficult to work on, so I'd find the offending leak first. Was it used in fresh or salt water? how old? Hope this helps. Nik
__________________

__________________
matata is offline   Reply With Quote
Old 18 February 2019, 07:57   #3
Member
 
Fender's Avatar
 
Country: UK - England
Make: Zodiac
Length: under 3m
Engine: Scull
Join Date: Dec 2014
Posts: 364
+1 for a pressure test - I change our leg oil at the start and also mid-season, that way I feel you can get ahead of any issues, good luck!
__________________
Fender is offline   Reply With Quote
Old 18 February 2019, 11:26   #4
Trade member
 
Country: UK - England
Town: Warrington
Boat name: Seal
Make: Excel
Length: 3m +
Engine: Outboard
Join Date: Dec 2017
Posts: 66
Send a message via Skype™ to goearth
What sometimes happens is that the prop hits something, and slightly bends the output shaft. This means that the seals cannot seal properly, letting in water.

Obviously don't know if that is the problem in this case; but I would suggesting seeing if the prop has any dings in it as a result of hitting something; and also checking the output shaft to ensure that it runs true. (I can't see all the blades of the prop from the photo.)
__________________
Martin Berman, Director, Go Earth Ltd
www.boatsearch.earth
mobile 07 803 938 805
email martin.berman@boatsearch.earth
goearth is offline   Reply With Quote
Old 18 February 2019, 21:36   #5
Member
 
Country: Other
Town: Langkawi, Malaysia
Length: no boat
Join Date: Dec 2005
Posts: 28
Since the gearbox needs to be worked on, would suggest to change both the drive shaft and prop shaft seal as well. Check both shaft to see if there is any scouring on the shaft where the seals comes in contact. Also do a run out test of the prop shaft with a micrometer to be safe.
__________________
Eric is offline   Reply With Quote
Old 19 February 2019, 02:05   #6
Member
 
spartacus's Avatar
 
Country: UK - Scotland
Town: Aberdeenshire
Boat name: Sula
Make: Ribcraft 4.8m
Length: 4m +
Engine: Tohatsu 60hp + aux
MMSI: 235087213
Join Date: Jun 2007
Posts: 3,719
RIBase
Quote:
Originally Posted by matata View Post
Hi Swifty, just working on my yam gearbox also....The oil should be a golden colour...
If you're using SAE 80/90 Yamlube, its golden syrup stuff, but Quicksilver SAE 90 high performance gear oil looks like this (except emulsification of course).
__________________
Is that with or without VAT?
spartacus is offline   Reply With Quote
Old 19 February 2019, 06:04   #7
Member
 
Country: UK - England
Town: Retford
Boat name: Spy-sea-one
Make: Excel 435
Length: 4m +
Engine: Suzuki Outboard/25/4
Join Date: Oct 2011
Posts: 5,563
The oil is very black is that exhaust contamination?
__________________
jeffstevens763@g is offline   Reply With Quote
Old 20 February 2019, 07:08   #8
Member
 
Country: Australia
Town: Dalmeny
Make: zodiac
Length: 5m +
Engine: outboard
Join Date: May 2015
Posts: 975
Here the most common cause of seals leaking is from fishing line getting around the prop then inside onto the shaft, where it can damage the seals.

My advice would be to find a decent mobile mechanic who could show you how to change the seals incase it happens again.

As the guys state, gearbox oil is like golden syrup, I replace mine every 100hrs where it looks the same clear golden colour on removal as the day I put it in. By the way 100hrs comes around four times per year on my engine.
__________________
jonp is offline   Reply With Quote
Old 21 February 2019, 04:36   #9
Member
 
Country: UK - England
Town: Nr Faversham, Kent
Boat name: C Rider
Make: Avon
Length: 5m +
Engine: Yam 80
Join Date: Jan 2005
Posts: 486
Thanks for the comments. I have always changed the oil regularly and never seen this before.
I am going to attempt a pressure test first to identify where the original problem is. For cleaning out the gunk, I was going to flush with diesel to get as much crud out before filling with oil.
__________________
Searider - The Best 5.4 x Far
Swifty is offline   Reply With Quote
Old 21 February 2019, 05:17   #10
Member
 
Country: UK - Scotland
Town: north ayrshire
Boat name: charlie girl
Make: reiver 3.8/regal3760
Length: 10m +
Engine: 40hp 2st 2x6lp 315
Join Date: Jul 2009
Posts: 2,280
Bear in mind that a pressure test may not show the fault as the shaft seals are in pairs back to back, one to keep oil in the other water out
It might help you but it isnt definitive. a vacuum test may help to find leaks going inwards but again its not 100% as its a static test ,personally I'd replace all the seals in the box for peace of mind . Yamaha seals are just metric seals so relatively easy to source from a bearing stockist if the genuine items are extortionate prices or long lead time, just make sure they have stainless garter springs
__________________
beamishken is offline   Reply With Quote
Old 21 February 2019, 08:39   #11
Member
 
Country: UK - England
Town: Liverpool
Length: no boat
Join Date: May 2015
Posts: 183
Do you remember what colour the oil was going in?. How many hours has it been in? Nik
__________________
matata is offline   Reply With Quote
Old 25 February 2019, 07:29   #12
Member
 
Country: UK - England
Town: Nr Faversham, Kent
Boat name: C Rider
Make: Avon
Length: 5m +
Engine: Yam 80
Join Date: Jan 2005
Posts: 486
Thanks for all your comments.

So had a try with pressurising and the input shaft and prop shaft blew easily but there was no obvious signs of failure, shifter shaft held fine.

Have opened up the gearbox and washed out the emulsified oil and the trapped water (was sitting somewhere out of reach of the drain??). Inspecting the contents there's no sign of corrosion or damage. - pictures attached. Main shafts don't appear to have deep grooves where the seals run.

I am going to order new seals allround and water pump gaskets. Only dodgy looking bit is the water pump lower casing, but may clean up ok.

Anything else worth checking at this stage?
Attached Thumbnails
Click image for larger version

Name:	IMG_0354[1].jpg
Views:	72
Size:	139.9 KB
ID:	128560   Click image for larger version

Name:	IMG_0355[1].jpg
Views:	74
Size:	121.4 KB
ID:	128561   Click image for larger version

Name:	IMG_0356[1].jpg
Views:	68
Size:	155.3 KB
ID:	128562  
__________________
Searider - The Best 5.4 x Far
Swifty is offline   Reply With Quote
Old 25 February 2019, 09:01   #13
Member
 
spartacus's Avatar
 
Country: UK - Scotland
Town: Aberdeenshire
Boat name: Sula
Make: Ribcraft 4.8m
Length: 4m +
Engine: Tohatsu 60hp + aux
MMSI: 235087213
Join Date: Jun 2007
Posts: 3,719
RIBase
Renew 'o' ring on dog clutch gear rod. Also 'o' ring under water pump above drive shaft bearing.
__________________
Is that with or without VAT?
spartacus is offline   Reply With Quote
Old 25 February 2019, 15:36   #14
Member
 
A1an's Avatar
 
Country: UK - Scotland
Town: Fort William
Make: Humber Destroyer
Length: 5m +
Engine: Yamaha F80
Join Date: Mar 2012
Posts: 2,323
RIBase
What is the history to the gearbox? How many hours on it? Were you the last person to service it?


Personally id have changed the prop shaft seal and put new washers on the fill/vent plugs and run it to see if water appeared again before tearing the whole gearbox apart.


I'm of the belief 'if it aint broke don't fix it'
__________________
There is a place on this planet for all of Gods creatures.........right next to my tatties and gravy.
A1an is offline   Reply With Quote
Old 25 February 2019, 16:12   #15
Member
 
Country: UK - England
Town: Liverpool
Length: no boat
Join Date: May 2015
Posts: 183
Hi Swifty, you've done a great job. I'm watching this with interest as we have a dribble of water in the oil in ours. Did you have diffs removing the output carrier or generally dismantling it due to corrosion etc??
__________________
matata is offline   Reply With Quote
Old 25 February 2019, 17:15   #16
Member
 
spartacus's Avatar
 
Country: UK - Scotland
Town: Aberdeenshire
Boat name: Sula
Make: Ribcraft 4.8m
Length: 4m +
Engine: Tohatsu 60hp + aux
MMSI: 235087213
Join Date: Jun 2007
Posts: 3,719
RIBase
That water pump lower housing looks like Swiss cheese. If the surface has deteriorated to such an extent, it would be worth replacing. No point buying new waterpump gaskets if they're not seated properly. There's Yamaha parts diagrams on Boats.net. Easy to navigate with engine year. Think part is around £90 plus shipping.

While you're there check the sacrificial anodes on the engine to see they are doing their job, including the earth cables on the leg.

I've started using Salt Away at the end of the season. Granted it wouldn't stop water ingress on a failed seal, but think of the cooling passages, water jacket, thermostat.
__________________
Is that with or without VAT?
spartacus is offline   Reply With Quote
Old 26 February 2019, 10:11   #17
Member
 
Country: UK - England
Town: Nr Faversham, Kent
Boat name: C Rider
Make: Avon
Length: 5m +
Engine: Yam 80
Join Date: Jan 2005
Posts: 486
To answer your questions...

I have indeed ordered a new water pump housing at £81 along with all O rings and seals. Total is about £150 for parts.

The ring nut was a bugger to remove. I started by drifting it off but it started to flatten, it's made of alloy, so made a jig out of sheet steel and a couple of M8 bolts. Two of us using long prybars between the jig and the propshaft shifted it.
Hub carrier came out easily with a puller but I did have to make some extension arms for the puller to reach from the end of the prop shaft.

The engine is circa 1998 and total hours are unknown, but probably a couple of thousand. It's done 350 hours since the power head rebuild a few years ago. Gearbox was overhauled two years ago by Yam dealer as the gearshift was getting clonky. They had to drill the ring nut to remove it. I was very relieved when they reported all internals were in good condition.

I usually change engine & gear oil every year, spark plugs & impeller every three years. I didn't change oil last year due to the rebuild and low hours. With hindsight, I should have done it anyway and not trusted the dealer. We live and learn.
__________________
Searider - The Best 5.4 x Far
Swifty is offline   Reply With Quote
Old 26 February 2019, 11:29   #18
Member
 
Country: UK - England
Town: Retford
Boat name: Spy-sea-one
Make: Excel 435
Length: 4m +
Engine: Suzuki Outboard/25/4
Join Date: Oct 2011
Posts: 5,563
swifty any idea why the oil is black very interested because i've seen it before in a johnson 15 hp it smelt like exhaust fumes but wasn't sure it had the correct oil but this had no water ingress.

cheers jeff
__________________
jeffstevens763@g is offline   Reply With Quote
Old 26 February 2019, 12:20   #19
Member
 
Country: UK - England
Town: Nr Faversham, Kent
Boat name: C Rider
Make: Avon
Length: 5m +
Engine: Yam 80
Join Date: Jan 2005
Posts: 486
Quote:
Originally Posted by jeffstevens763@g View Post
swifty any idea why the oil is black...

cheers jeff
Nope, it didn't really smell of EP90 either! It had the consistancy of epoxy glue and the total volume of what came out was less than half the normal capacity. Maybe oil was being forced out when running hot and water sucked in as it cooled down.

I think I was lucky to uncover the problem before complete destruction.
__________________
Searider - The Best 5.4 x Far
Swifty is offline   Reply With Quote
Old 26 February 2019, 12:59   #20
Member
 
Country: UK - England
Town: Retford
Boat name: Spy-sea-one
Make: Excel 435
Length: 4m +
Engine: Suzuki Outboard/25/4
Join Date: Oct 2011
Posts: 5,563
Quote:
Originally Posted by Swifty View Post
Nope, it didn't really smell of EP90 either! It had the consistancy of epoxy glue and the total volume of what came out was less than half the normal capacity. Maybe oil was being forced out when running hot and water sucked in as it cooled down.

I think I was lucky to uncover the problem before complete destruction.
I remember in the old days when the cylinder head gasket went on the car you had a creamy residue in the rocker box but that was cream to white in colour
__________________

__________________
jeffstevens763@g is offline   Reply With Quote
Reply

Tags
yamaha

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 02:53.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
×